Bug Summary

File:lib/Analysis/InstructionSimplify.cpp
Warning:line 377, column 20
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name InstructionSimplify.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/Analysis -I /build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn329677/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/Analysis -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-04-11-031539-24776-1 -x c++ /build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp

/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp

1//===- InstructionSimplify.cpp - Fold instruction operands ----------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements routines for folding instructions into simpler forms
11// that do not require creating new instructions. This does constant folding
12// ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
13// returning a constant ("and i32 %x, 0" -> "0") or an already existing value
14// ("and i32 %x, %x" -> "%x"). All operands are assumed to have already been
15// simplified: This is usually true and assuming it simplifies the logic (if
16// they have not been simplified then results are correct but maybe suboptimal).
17//
18//===----------------------------------------------------------------------===//
19
20#include "llvm/Analysis/InstructionSimplify.h"
21#include "llvm/ADT/SetVector.h"
22#include "llvm/ADT/Statistic.h"
23#include "llvm/Analysis/AliasAnalysis.h"
24#include "llvm/Analysis/AssumptionCache.h"
25#include "llvm/Analysis/CaptureTracking.h"
26#include "llvm/Analysis/CmpInstAnalysis.h"
27#include "llvm/Analysis/ConstantFolding.h"
28#include "llvm/Analysis/LoopAnalysisManager.h"
29#include "llvm/Analysis/MemoryBuiltins.h"
30#include "llvm/Analysis/ValueTracking.h"
31#include "llvm/Analysis/VectorUtils.h"
32#include "llvm/IR/ConstantRange.h"
33#include "llvm/IR/DataLayout.h"
34#include "llvm/IR/Dominators.h"
35#include "llvm/IR/GetElementPtrTypeIterator.h"
36#include "llvm/IR/GlobalAlias.h"
37#include "llvm/IR/Operator.h"
38#include "llvm/IR/PatternMatch.h"
39#include "llvm/IR/ValueHandle.h"
40#include "llvm/Support/KnownBits.h"
41#include <algorithm>
42using namespace llvm;
43using namespace llvm::PatternMatch;
44
45#define DEBUG_TYPE"instsimplify" "instsimplify"
46
47enum { RecursionLimit = 3 };
48
49STATISTIC(NumExpand, "Number of expansions")static llvm::Statistic NumExpand = {"instsimplify", "NumExpand"
, "Number of expansions", {0}, {false}}
;
50STATISTIC(NumReassoc, "Number of reassociations")static llvm::Statistic NumReassoc = {"instsimplify", "NumReassoc"
, "Number of reassociations", {0}, {false}}
;
51
52static Value *SimplifyAndInst(Value *, Value *, const SimplifyQuery &, unsigned);
53static Value *SimplifyBinOp(unsigned, Value *, Value *, const SimplifyQuery &,
54 unsigned);
55static Value *SimplifyFPBinOp(unsigned, Value *, Value *, const FastMathFlags &,
56 const SimplifyQuery &, unsigned);
57static Value *SimplifyCmpInst(unsigned, Value *, Value *, const SimplifyQuery &,
58 unsigned);
59static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
60 const SimplifyQuery &Q, unsigned MaxRecurse);
61static Value *SimplifyOrInst(Value *, Value *, const SimplifyQuery &, unsigned);
62static Value *SimplifyXorInst(Value *, Value *, const SimplifyQuery &, unsigned);
63static Value *SimplifyCastInst(unsigned, Value *, Type *,
64 const SimplifyQuery &, unsigned);
65
66/// For a boolean type or a vector of boolean type, return false or a vector
67/// with every element false.
68static Constant *getFalse(Type *Ty) {
69 return ConstantInt::getFalse(Ty);
70}
71
72/// For a boolean type or a vector of boolean type, return true or a vector
73/// with every element true.
74static Constant *getTrue(Type *Ty) {
75 return ConstantInt::getTrue(Ty);
76}
77
78/// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
79static bool isSameCompare(Value *V, CmpInst::Predicate Pred, Value *LHS,
80 Value *RHS) {
81 CmpInst *Cmp = dyn_cast<CmpInst>(V);
82 if (!Cmp)
83 return false;
84 CmpInst::Predicate CPred = Cmp->getPredicate();
85 Value *CLHS = Cmp->getOperand(0), *CRHS = Cmp->getOperand(1);
86 if (CPred == Pred && CLHS == LHS && CRHS == RHS)
87 return true;
88 return CPred == CmpInst::getSwappedPredicate(Pred) && CLHS == RHS &&
89 CRHS == LHS;
90}
91
92/// Does the given value dominate the specified phi node?
93static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) {
94 Instruction *I = dyn_cast<Instruction>(V);
95 if (!I)
96 // Arguments and constants dominate all instructions.
97 return true;
98
99 // If we are processing instructions (and/or basic blocks) that have not been
100 // fully added to a function, the parent nodes may still be null. Simply
101 // return the conservative answer in these cases.
102 if (!I->getParent() || !P->getParent() || !I->getParent()->getParent())
103 return false;
104
105 // If we have a DominatorTree then do a precise test.
106 if (DT)
107 return DT->dominates(I, P);
108
109 // Otherwise, if the instruction is in the entry block and is not an invoke,
110 // then it obviously dominates all phi nodes.
111 if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() &&
112 !isa<InvokeInst>(I))
113 return true;
114
115 return false;
116}
117
118/// Simplify "A op (B op' C)" by distributing op over op', turning it into
119/// "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is
120/// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS.
121/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)".
122/// Returns the simplified value, or null if no simplification was performed.
123static Value *ExpandBinOp(Instruction::BinaryOps Opcode, Value *LHS, Value *RHS,
124 Instruction::BinaryOps OpcodeToExpand,
125 const SimplifyQuery &Q, unsigned MaxRecurse) {
126 // Recursion is always used, so bail out at once if we already hit the limit.
127 if (!MaxRecurse--)
128 return nullptr;
129
130 // Check whether the expression has the form "(A op' B) op C".
131 if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS))
132 if (Op0->getOpcode() == OpcodeToExpand) {
133 // It does! Try turning it into "(A op C) op' (B op C)".
134 Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS;
135 // Do "A op C" and "B op C" both simplify?
136 if (Value *L = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse))
137 if (Value *R = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
138 // They do! Return "L op' R" if it simplifies or is already available.
139 // If "L op' R" equals "A op' B" then "L op' R" is just the LHS.
140 if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand)
141 && L == B && R == A)) {
142 ++NumExpand;
143 return LHS;
144 }
145 // Otherwise return "L op' R" if it simplifies.
146 if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
147 ++NumExpand;
148 return V;
149 }
150 }
151 }
152
153 // Check whether the expression has the form "A op (B op' C)".
154 if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS))
155 if (Op1->getOpcode() == OpcodeToExpand) {
156 // It does! Try turning it into "(A op B) op' (A op C)".
157 Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1);
158 // Do "A op B" and "A op C" both simplify?
159 if (Value *L = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse))
160 if (Value *R = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) {
161 // They do! Return "L op' R" if it simplifies or is already available.
162 // If "L op' R" equals "B op' C" then "L op' R" is just the RHS.
163 if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand)
164 && L == C && R == B)) {
165 ++NumExpand;
166 return RHS;
167 }
168 // Otherwise return "L op' R" if it simplifies.
169 if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
170 ++NumExpand;
171 return V;
172 }
173 }
174 }
175
176 return nullptr;
177}
178
179/// Generic simplifications for associative binary operations.
180/// Returns the simpler value, or null if none was found.
181static Value *SimplifyAssociativeBinOp(Instruction::BinaryOps Opcode,
182 Value *LHS, Value *RHS,
183 const SimplifyQuery &Q,
184 unsigned MaxRecurse) {
185 assert(Instruction::isAssociative(Opcode) && "Not an associative operation!")(static_cast <bool> (Instruction::isAssociative(Opcode)
&& "Not an associative operation!") ? void (0) : __assert_fail
("Instruction::isAssociative(Opcode) && \"Not an associative operation!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 185, __extension__ __PRETTY_FUNCTION__))
;
186
187 // Recursion is always used, so bail out at once if we already hit the limit.
188 if (!MaxRecurse--)
189 return nullptr;
190
191 BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
192 BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
193
194 // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely.
195 if (Op0 && Op0->getOpcode() == Opcode) {
196 Value *A = Op0->getOperand(0);
197 Value *B = Op0->getOperand(1);
198 Value *C = RHS;
199
200 // Does "B op C" simplify?
201 if (Value *V = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
202 // It does! Return "A op V" if it simplifies or is already available.
203 // If V equals B then "A op V" is just the LHS.
204 if (V == B) return LHS;
205 // Otherwise return "A op V" if it simplifies.
206 if (Value *W = SimplifyBinOp(Opcode, A, V, Q, MaxRecurse)) {
207 ++NumReassoc;
208 return W;
209 }
210 }
211 }
212
213 // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely.
214 if (Op1 && Op1->getOpcode() == Opcode) {
215 Value *A = LHS;
216 Value *B = Op1->getOperand(0);
217 Value *C = Op1->getOperand(1);
218
219 // Does "A op B" simplify?
220 if (Value *V = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) {
221 // It does! Return "V op C" if it simplifies or is already available.
222 // If V equals B then "V op C" is just the RHS.
223 if (V == B) return RHS;
224 // Otherwise return "V op C" if it simplifies.
225 if (Value *W = SimplifyBinOp(Opcode, V, C, Q, MaxRecurse)) {
226 ++NumReassoc;
227 return W;
228 }
229 }
230 }
231
232 // The remaining transforms require commutativity as well as associativity.
233 if (!Instruction::isCommutative(Opcode))
234 return nullptr;
235
236 // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
237 if (Op0 && Op0->getOpcode() == Opcode) {
238 Value *A = Op0->getOperand(0);
239 Value *B = Op0->getOperand(1);
240 Value *C = RHS;
241
242 // Does "C op A" simplify?
243 if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
244 // It does! Return "V op B" if it simplifies or is already available.
245 // If V equals A then "V op B" is just the LHS.
246 if (V == A) return LHS;
247 // Otherwise return "V op B" if it simplifies.
248 if (Value *W = SimplifyBinOp(Opcode, V, B, Q, MaxRecurse)) {
249 ++NumReassoc;
250 return W;
251 }
252 }
253 }
254
255 // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely.
256 if (Op1 && Op1->getOpcode() == Opcode) {
257 Value *A = LHS;
258 Value *B = Op1->getOperand(0);
259 Value *C = Op1->getOperand(1);
260
261 // Does "C op A" simplify?
262 if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
263 // It does! Return "B op V" if it simplifies or is already available.
264 // If V equals C then "B op V" is just the RHS.
265 if (V == C) return RHS;
266 // Otherwise return "B op V" if it simplifies.
267 if (Value *W = SimplifyBinOp(Opcode, B, V, Q, MaxRecurse)) {
268 ++NumReassoc;
269 return W;
270 }
271 }
272 }
273
274 return nullptr;
275}
276
277/// In the case of a binary operation with a select instruction as an operand,
278/// try to simplify the binop by seeing whether evaluating it on both branches
279/// of the select results in the same value. Returns the common value if so,
280/// otherwise returns null.
281static Value *ThreadBinOpOverSelect(Instruction::BinaryOps Opcode, Value *LHS,
282 Value *RHS, const SimplifyQuery &Q,
283 unsigned MaxRecurse) {
284 // Recursion is always used, so bail out at once if we already hit the limit.
285 if (!MaxRecurse--)
286 return nullptr;
287
288 SelectInst *SI;
289 if (isa<SelectInst>(LHS)) {
290 SI = cast<SelectInst>(LHS);
291 } else {
292 assert(isa<SelectInst>(RHS) && "No select instruction operand!")(static_cast <bool> (isa<SelectInst>(RHS) &&
"No select instruction operand!") ? void (0) : __assert_fail
("isa<SelectInst>(RHS) && \"No select instruction operand!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 292, __extension__ __PRETTY_FUNCTION__))
;
293 SI = cast<SelectInst>(RHS);
294 }
295
296 // Evaluate the BinOp on the true and false branches of the select.
297 Value *TV;
298 Value *FV;
299 if (SI == LHS) {
300 TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, Q, MaxRecurse);
301 FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, Q, MaxRecurse);
302 } else {
303 TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), Q, MaxRecurse);
304 FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), Q, MaxRecurse);
305 }
306
307 // If they simplified to the same value, then return the common value.
308 // If they both failed to simplify then return null.
309 if (TV == FV)
310 return TV;
311
312 // If one branch simplified to undef, return the other one.
313 if (TV && isa<UndefValue>(TV))
314 return FV;
315 if (FV && isa<UndefValue>(FV))
316 return TV;
317
318 // If applying the operation did not change the true and false select values,
319 // then the result of the binop is the select itself.
320 if (TV == SI->getTrueValue() && FV == SI->getFalseValue())
321 return SI;
322
323 // If one branch simplified and the other did not, and the simplified
324 // value is equal to the unsimplified one, return the simplified value.
325 // For example, select (cond, X, X & Z) & Z -> X & Z.
326 if ((FV && !TV) || (TV && !FV)) {
327 // Check that the simplified value has the form "X op Y" where "op" is the
328 // same as the original operation.
329 Instruction *Simplified = dyn_cast<Instruction>(FV ? FV : TV);
330 if (Simplified && Simplified->getOpcode() == unsigned(Opcode)) {
331 // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS".
332 // We already know that "op" is the same as for the simplified value. See
333 // if the operands match too. If so, return the simplified value.
334 Value *UnsimplifiedBranch = FV ? SI->getTrueValue() : SI->getFalseValue();
335 Value *UnsimplifiedLHS = SI == LHS ? UnsimplifiedBranch : LHS;
336 Value *UnsimplifiedRHS = SI == LHS ? RHS : UnsimplifiedBranch;
337 if (Simplified->getOperand(0) == UnsimplifiedLHS &&
338 Simplified->getOperand(1) == UnsimplifiedRHS)
339 return Simplified;
340 if (Simplified->isCommutative() &&
341 Simplified->getOperand(1) == UnsimplifiedLHS &&
342 Simplified->getOperand(0) == UnsimplifiedRHS)
343 return Simplified;
344 }
345 }
346
347 return nullptr;
348}
349
350/// In the case of a comparison with a select instruction, try to simplify the
351/// comparison by seeing whether both branches of the select result in the same
352/// value. Returns the common value if so, otherwise returns null.
353static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS,
354 Value *RHS, const SimplifyQuery &Q,
355 unsigned MaxRecurse) {
356 // Recursion is always used, so bail out at once if we already hit the limit.
357 if (!MaxRecurse--)
17
Taking false branch
358 return nullptr;
359
360 // Make sure the select is on the LHS.
361 if (!isa<SelectInst>(LHS)) {
18
Taking true branch
362 std::swap(LHS, RHS);
363 Pred = CmpInst::getSwappedPredicate(Pred);
364 }
365 assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!")(static_cast <bool> (isa<SelectInst>(LHS) &&
"Not comparing with a select instruction!") ? void (0) : __assert_fail
("isa<SelectInst>(LHS) && \"Not comparing with a select instruction!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 365, __extension__ __PRETTY_FUNCTION__))
;
366 SelectInst *SI = cast<SelectInst>(LHS);
367 Value *Cond = SI->getCondition();
19
Calling 'SelectInst::getCondition'
22
Returning from 'SelectInst::getCondition'
23
'Cond' initialized here
368 Value *TV = SI->getTrueValue();
369 Value *FV = SI->getFalseValue();
370
371 // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
372 // Does "cmp TV, RHS" simplify?
373 Value *TCmp = SimplifyCmpInst(Pred, TV, RHS, Q, MaxRecurse);
374 if (TCmp == Cond) {
24
Assuming 'TCmp' is equal to 'Cond'
25
Assuming pointer value is null
26
Taking true branch
375 // It not only simplified, it simplified to the select condition. Replace
376 // it with 'true'.
377 TCmp = getTrue(Cond->getType());
27
Called C++ object pointer is null
378 } else if (!TCmp) {
379 // It didn't simplify. However if "cmp TV, RHS" is equal to the select
380 // condition then we can replace it with 'true'. Otherwise give up.
381 if (!isSameCompare(Cond, Pred, TV, RHS))
382 return nullptr;
383 TCmp = getTrue(Cond->getType());
384 }
385
386 // Does "cmp FV, RHS" simplify?
387 Value *FCmp = SimplifyCmpInst(Pred, FV, RHS, Q, MaxRecurse);
388 if (FCmp == Cond) {
389 // It not only simplified, it simplified to the select condition. Replace
390 // it with 'false'.
391 FCmp = getFalse(Cond->getType());
392 } else if (!FCmp) {
393 // It didn't simplify. However if "cmp FV, RHS" is equal to the select
394 // condition then we can replace it with 'false'. Otherwise give up.
395 if (!isSameCompare(Cond, Pred, FV, RHS))
396 return nullptr;
397 FCmp = getFalse(Cond->getType());
398 }
399
400 // If both sides simplified to the same value, then use it as the result of
401 // the original comparison.
402 if (TCmp == FCmp)
403 return TCmp;
404
405 // The remaining cases only make sense if the select condition has the same
406 // type as the result of the comparison, so bail out if this is not so.
407 if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy())
408 return nullptr;
409 // If the false value simplified to false, then the result of the compare
410 // is equal to "Cond && TCmp". This also catches the case when the false
411 // value simplified to false and the true value to true, returning "Cond".
412 if (match(FCmp, m_Zero()))
413 if (Value *V = SimplifyAndInst(Cond, TCmp, Q, MaxRecurse))
414 return V;
415 // If the true value simplified to true, then the result of the compare
416 // is equal to "Cond || FCmp".
417 if (match(TCmp, m_One()))
418 if (Value *V = SimplifyOrInst(Cond, FCmp, Q, MaxRecurse))
419 return V;
420 // Finally, if the false value simplified to true and the true value to
421 // false, then the result of the compare is equal to "!Cond".
422 if (match(FCmp, m_One()) && match(TCmp, m_Zero()))
423 if (Value *V =
424 SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()),
425 Q, MaxRecurse))
426 return V;
427
428 return nullptr;
429}
430
431/// In the case of a binary operation with an operand that is a PHI instruction,
432/// try to simplify the binop by seeing whether evaluating it on the incoming
433/// phi values yields the same result for every value. If so returns the common
434/// value, otherwise returns null.
435static Value *ThreadBinOpOverPHI(Instruction::BinaryOps Opcode, Value *LHS,
436 Value *RHS, const SimplifyQuery &Q,
437 unsigned MaxRecurse) {
438 // Recursion is always used, so bail out at once if we already hit the limit.
439 if (!MaxRecurse--)
440 return nullptr;
441
442 PHINode *PI;
443 if (isa<PHINode>(LHS)) {
444 PI = cast<PHINode>(LHS);
445 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
446 if (!ValueDominatesPHI(RHS, PI, Q.DT))
447 return nullptr;
448 } else {
449 assert(isa<PHINode>(RHS) && "No PHI instruction operand!")(static_cast <bool> (isa<PHINode>(RHS) &&
"No PHI instruction operand!") ? void (0) : __assert_fail ("isa<PHINode>(RHS) && \"No PHI instruction operand!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 449, __extension__ __PRETTY_FUNCTION__))
;
450 PI = cast<PHINode>(RHS);
451 // Bail out if LHS and the phi may be mutually interdependent due to a loop.
452 if (!ValueDominatesPHI(LHS, PI, Q.DT))
453 return nullptr;
454 }
455
456 // Evaluate the BinOp on the incoming phi values.
457 Value *CommonValue = nullptr;
458 for (Value *Incoming : PI->incoming_values()) {
459 // If the incoming value is the phi node itself, it can safely be skipped.
460 if (Incoming == PI) continue;
461 Value *V = PI == LHS ?
462 SimplifyBinOp(Opcode, Incoming, RHS, Q, MaxRecurse) :
463 SimplifyBinOp(Opcode, LHS, Incoming, Q, MaxRecurse);
464 // If the operation failed to simplify, or simplified to a different value
465 // to previously, then give up.
466 if (!V || (CommonValue && V != CommonValue))
467 return nullptr;
468 CommonValue = V;
469 }
470
471 return CommonValue;
472}
473
474/// In the case of a comparison with a PHI instruction, try to simplify the
475/// comparison by seeing whether comparing with all of the incoming phi values
476/// yields the same result every time. If so returns the common result,
477/// otherwise returns null.
478static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
479 const SimplifyQuery &Q, unsigned MaxRecurse) {
480 // Recursion is always used, so bail out at once if we already hit the limit.
481 if (!MaxRecurse--)
482 return nullptr;
483
484 // Make sure the phi is on the LHS.
485 if (!isa<PHINode>(LHS)) {
486 std::swap(LHS, RHS);
487 Pred = CmpInst::getSwappedPredicate(Pred);
488 }
489 assert(isa<PHINode>(LHS) && "Not comparing with a phi instruction!")(static_cast <bool> (isa<PHINode>(LHS) &&
"Not comparing with a phi instruction!") ? void (0) : __assert_fail
("isa<PHINode>(LHS) && \"Not comparing with a phi instruction!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 489, __extension__ __PRETTY_FUNCTION__))
;
490 PHINode *PI = cast<PHINode>(LHS);
491
492 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
493 if (!ValueDominatesPHI(RHS, PI, Q.DT))
494 return nullptr;
495
496 // Evaluate the BinOp on the incoming phi values.
497 Value *CommonValue = nullptr;
498 for (Value *Incoming : PI->incoming_values()) {
499 // If the incoming value is the phi node itself, it can safely be skipped.
500 if (Incoming == PI) continue;
501 Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse);
502 // If the operation failed to simplify, or simplified to a different value
503 // to previously, then give up.
504 if (!V || (CommonValue && V != CommonValue))
505 return nullptr;
506 CommonValue = V;
507 }
508
509 return CommonValue;
510}
511
512static Constant *foldOrCommuteConstant(Instruction::BinaryOps Opcode,
513 Value *&Op0, Value *&Op1,
514 const SimplifyQuery &Q) {
515 if (auto *CLHS = dyn_cast<Constant>(Op0)) {
516 if (auto *CRHS = dyn_cast<Constant>(Op1))
517 return ConstantFoldBinaryOpOperands(Opcode, CLHS, CRHS, Q.DL);
518
519 // Canonicalize the constant to the RHS if this is a commutative operation.
520 if (Instruction::isCommutative(Opcode))
521 std::swap(Op0, Op1);
522 }
523 return nullptr;
524}
525
526/// Given operands for an Add, see if we can fold the result.
527/// If not, this returns null.
528static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
529 const SimplifyQuery &Q, unsigned MaxRecurse) {
530 if (Constant *C = foldOrCommuteConstant(Instruction::Add, Op0, Op1, Q))
531 return C;
532
533 // X + undef -> undef
534 if (match(Op1, m_Undef()))
535 return Op1;
536
537 // X + 0 -> X
538 if (match(Op1, m_Zero()))
539 return Op0;
540
541 // X + (Y - X) -> Y
542 // (Y - X) + X -> Y
543 // Eg: X + -X -> 0
544 Value *Y = nullptr;
545 if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) ||
546 match(Op0, m_Sub(m_Value(Y), m_Specific(Op1))))
547 return Y;
548
549 // X + ~X -> -1 since ~X = -X-1
550 Type *Ty = Op0->getType();
551 if (match(Op0, m_Not(m_Specific(Op1))) ||
552 match(Op1, m_Not(m_Specific(Op0))))
553 return Constant::getAllOnesValue(Ty);
554
555 // add nsw/nuw (xor Y, signmask), signmask --> Y
556 // The no-wrapping add guarantees that the top bit will be set by the add.
557 // Therefore, the xor must be clearing the already set sign bit of Y.
558 if ((isNSW || isNUW) && match(Op1, m_SignMask()) &&
559 match(Op0, m_Xor(m_Value(Y), m_SignMask())))
560 return Y;
561
562 /// i1 add -> xor.
563 if (MaxRecurse && Op0->getType()->isIntOrIntVectorTy(1))
564 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
565 return V;
566
567 // Try some generic simplifications for associative operations.
568 if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, Q,
569 MaxRecurse))
570 return V;
571
572 // Threading Add over selects and phi nodes is pointless, so don't bother.
573 // Threading over the select in "A + select(cond, B, C)" means evaluating
574 // "A+B" and "A+C" and seeing if they are equal; but they are equal if and
575 // only if B and C are equal. If B and C are equal then (since we assume
576 // that operands have already been simplified) "select(cond, B, C)" should
577 // have been simplified to the common value of B and C already. Analysing
578 // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
579 // for threading over phi nodes.
580
581 return nullptr;
582}
583
584Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
585 const SimplifyQuery &Query) {
586 return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query, RecursionLimit);
587}
588
589/// \brief Compute the base pointer and cumulative constant offsets for V.
590///
591/// This strips all constant offsets off of V, leaving it the base pointer, and
592/// accumulates the total constant offset applied in the returned constant. It
593/// returns 0 if V is not a pointer, and returns the constant '0' if there are
594/// no constant offsets applied.
595///
596/// This is very similar to GetPointerBaseWithConstantOffset except it doesn't
597/// follow non-inbounds geps. This allows it to remain usable for icmp ult/etc.
598/// folding.
599static Constant *stripAndComputeConstantOffsets(const DataLayout &DL, Value *&V,
600 bool AllowNonInbounds = false) {
601 assert(V->getType()->isPtrOrPtrVectorTy())(static_cast <bool> (V->getType()->isPtrOrPtrVectorTy
()) ? void (0) : __assert_fail ("V->getType()->isPtrOrPtrVectorTy()"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 601, __extension__ __PRETTY_FUNCTION__))
;
602
603 Type *IntPtrTy = DL.getIntPtrType(V->getType())->getScalarType();
604 APInt Offset = APInt::getNullValue(IntPtrTy->getIntegerBitWidth());
605
606 // Even though we don't look through PHI nodes, we could be called on an
607 // instruction in an unreachable block, which may be on a cycle.
608 SmallPtrSet<Value *, 4> Visited;
609 Visited.insert(V);
610 do {
611 if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
612 if ((!AllowNonInbounds && !GEP->isInBounds()) ||
613 !GEP->accumulateConstantOffset(DL, Offset))
614 break;
615 V = GEP->getPointerOperand();
616 } else if (Operator::getOpcode(V) == Instruction::BitCast) {
617 V = cast<Operator>(V)->getOperand(0);
618 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
619 if (GA->isInterposable())
620 break;
621 V = GA->getAliasee();
622 } else {
623 if (auto CS = CallSite(V))
624 if (Value *RV = CS.getReturnedArgOperand()) {
625 V = RV;
626 continue;
627 }
628 break;
629 }
630 assert(V->getType()->isPtrOrPtrVectorTy() && "Unexpected operand type!")(static_cast <bool> (V->getType()->isPtrOrPtrVectorTy
() && "Unexpected operand type!") ? void (0) : __assert_fail
("V->getType()->isPtrOrPtrVectorTy() && \"Unexpected operand type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 630, __extension__ __PRETTY_FUNCTION__))
;
631 } while (Visited.insert(V).second);
632
633 Constant *OffsetIntPtr = ConstantInt::get(IntPtrTy, Offset);
634 if (V->getType()->isVectorTy())
635 return ConstantVector::getSplat(V->getType()->getVectorNumElements(),
636 OffsetIntPtr);
637 return OffsetIntPtr;
638}
639
640/// \brief Compute the constant difference between two pointer values.
641/// If the difference is not a constant, returns zero.
642static Constant *computePointerDifference(const DataLayout &DL, Value *LHS,
643 Value *RHS) {
644 Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS);
645 Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS);
646
647 // If LHS and RHS are not related via constant offsets to the same base
648 // value, there is nothing we can do here.
649 if (LHS != RHS)
650 return nullptr;
651
652 // Otherwise, the difference of LHS - RHS can be computed as:
653 // LHS - RHS
654 // = (LHSOffset + Base) - (RHSOffset + Base)
655 // = LHSOffset - RHSOffset
656 return ConstantExpr::getSub(LHSOffset, RHSOffset);
657}
658
659/// Given operands for a Sub, see if we can fold the result.
660/// If not, this returns null.
661static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
662 const SimplifyQuery &Q, unsigned MaxRecurse) {
663 if (Constant *C = foldOrCommuteConstant(Instruction::Sub, Op0, Op1, Q))
664 return C;
665
666 // X - undef -> undef
667 // undef - X -> undef
668 if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
669 return UndefValue::get(Op0->getType());
670
671 // X - 0 -> X
672 if (match(Op1, m_Zero()))
673 return Op0;
674
675 // X - X -> 0
676 if (Op0 == Op1)
677 return Constant::getNullValue(Op0->getType());
678
679 // Is this a negation?
680 if (match(Op0, m_Zero())) {
681 // 0 - X -> 0 if the sub is NUW.
682 if (isNUW)
683 return Op0;
684
685 KnownBits Known = computeKnownBits(Op1, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
686 if (Known.Zero.isMaxSignedValue()) {
687 // Op1 is either 0 or the minimum signed value. If the sub is NSW, then
688 // Op1 must be 0 because negating the minimum signed value is undefined.
689 if (isNSW)
690 return Op0;
691
692 // 0 - X -> X if X is 0 or the minimum signed value.
693 return Op1;
694 }
695 }
696
697 // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
698 // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
699 Value *X = nullptr, *Y = nullptr, *Z = Op1;
700 if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
701 // See if "V === Y - Z" simplifies.
702 if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
703 // It does! Now see if "X + V" simplifies.
704 if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) {
705 // It does, we successfully reassociated!
706 ++NumReassoc;
707 return W;
708 }
709 // See if "V === X - Z" simplifies.
710 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
711 // It does! Now see if "Y + V" simplifies.
712 if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) {
713 // It does, we successfully reassociated!
714 ++NumReassoc;
715 return W;
716 }
717 }
718
719 // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
720 // For example, X - (X + 1) -> -1
721 X = Op0;
722 if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
723 // See if "V === X - Y" simplifies.
724 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
725 // It does! Now see if "V - Z" simplifies.
726 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) {
727 // It does, we successfully reassociated!
728 ++NumReassoc;
729 return W;
730 }
731 // See if "V === X - Z" simplifies.
732 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
733 // It does! Now see if "V - Y" simplifies.
734 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) {
735 // It does, we successfully reassociated!
736 ++NumReassoc;
737 return W;
738 }
739 }
740
741 // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
742 // For example, X - (X - Y) -> Y.
743 Z = Op0;
744 if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
745 // See if "V === Z - X" simplifies.
746 if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1))
747 // It does! Now see if "V + Y" simplifies.
748 if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) {
749 // It does, we successfully reassociated!
750 ++NumReassoc;
751 return W;
752 }
753
754 // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
755 if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) &&
756 match(Op1, m_Trunc(m_Value(Y))))
757 if (X->getType() == Y->getType())
758 // See if "V === X - Y" simplifies.
759 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
760 // It does! Now see if "trunc V" simplifies.
761 if (Value *W = SimplifyCastInst(Instruction::Trunc, V, Op0->getType(),
762 Q, MaxRecurse - 1))
763 // It does, return the simplified "trunc V".
764 return W;
765
766 // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
767 if (match(Op0, m_PtrToInt(m_Value(X))) &&
768 match(Op1, m_PtrToInt(m_Value(Y))))
769 if (Constant *Result = computePointerDifference(Q.DL, X, Y))
770 return ConstantExpr::getIntegerCast(Result, Op0->getType(), true);
771
772 // i1 sub -> xor.
773 if (MaxRecurse && Op0->getType()->isIntOrIntVectorTy(1))
774 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
775 return V;
776
777 // Threading Sub over selects and phi nodes is pointless, so don't bother.
778 // Threading over the select in "A - select(cond, B, C)" means evaluating
779 // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
780 // only if B and C are equal. If B and C are equal then (since we assume
781 // that operands have already been simplified) "select(cond, B, C)" should
782 // have been simplified to the common value of B and C already. Analysing
783 // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
784 // for threading over phi nodes.
785
786 return nullptr;
787}
788
789Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
790 const SimplifyQuery &Q) {
791 return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Q, RecursionLimit);
792}
793
794/// Given operands for a Mul, see if we can fold the result.
795/// If not, this returns null.
796static Value *SimplifyMulInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
797 unsigned MaxRecurse) {
798 if (Constant *C = foldOrCommuteConstant(Instruction::Mul, Op0, Op1, Q))
799 return C;
800
801 // X * undef -> 0
802 if (match(Op1, m_Undef()))
803 return Constant::getNullValue(Op0->getType());
804
805 // X * 0 -> 0
806 if (match(Op1, m_Zero()))
807 return Op1;
808
809 // X * 1 -> X
810 if (match(Op1, m_One()))
811 return Op0;
812
813 // (X / Y) * Y -> X if the division is exact.
814 Value *X = nullptr;
815 if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
816 match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
817 return X;
818
819 // i1 mul -> and.
820 if (MaxRecurse && Op0->getType()->isIntOrIntVectorTy(1))
821 if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1))
822 return V;
823
824 // Try some generic simplifications for associative operations.
825 if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q,
826 MaxRecurse))
827 return V;
828
829 // Mul distributes over Add. Try some generic simplifications based on this.
830 if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
831 Q, MaxRecurse))
832 return V;
833
834 // If the operation is with the result of a select instruction, check whether
835 // operating on either branch of the select always yields the same value.
836 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
837 if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q,
838 MaxRecurse))
839 return V;
840
841 // If the operation is with the result of a phi instruction, check whether
842 // operating on all incoming values of the phi always yields the same value.
843 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
844 if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q,
845 MaxRecurse))
846 return V;
847
848 return nullptr;
849}
850
851Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
852 return ::SimplifyMulInst(Op0, Op1, Q, RecursionLimit);
853}
854
855/// Check for common or similar folds of integer division or integer remainder.
856/// This applies to all 4 opcodes (sdiv/udiv/srem/urem).
857static Value *simplifyDivRem(Value *Op0, Value *Op1, bool IsDiv) {
858 Type *Ty = Op0->getType();
859
860 // X / undef -> undef
861 // X % undef -> undef
862 if (match(Op1, m_Undef()))
863 return Op1;
864
865 // X / 0 -> undef
866 // X % 0 -> undef
867 // We don't need to preserve faults!
868 if (match(Op1, m_Zero()))
869 return UndefValue::get(Ty);
870
871 // If any element of a constant divisor vector is zero or undef, the whole op
872 // is undef.
873 auto *Op1C = dyn_cast<Constant>(Op1);
874 if (Op1C && Ty->isVectorTy()) {
875 unsigned NumElts = Ty->getVectorNumElements();
876 for (unsigned i = 0; i != NumElts; ++i) {
877 Constant *Elt = Op1C->getAggregateElement(i);
878 if (Elt && (Elt->isNullValue() || isa<UndefValue>(Elt)))
879 return UndefValue::get(Ty);
880 }
881 }
882
883 // undef / X -> 0
884 // undef % X -> 0
885 if (match(Op0, m_Undef()))
886 return Constant::getNullValue(Ty);
887
888 // 0 / X -> 0
889 // 0 % X -> 0
890 if (match(Op0, m_Zero()))
891 return Op0;
892
893 // X / X -> 1
894 // X % X -> 0
895 if (Op0 == Op1)
896 return IsDiv ? ConstantInt::get(Ty, 1) : Constant::getNullValue(Ty);
897
898 // X / 1 -> X
899 // X % 1 -> 0
900 // If this is a boolean op (single-bit element type), we can't have
901 // division-by-zero or remainder-by-zero, so assume the divisor is 1.
902 if (match(Op1, m_One()) || Ty->isIntOrIntVectorTy(1))
903 return IsDiv ? Op0 : Constant::getNullValue(Ty);
904
905 return nullptr;
906}
907
908/// Given a predicate and two operands, return true if the comparison is true.
909/// This is a helper for div/rem simplification where we return some other value
910/// when we can prove a relationship between the operands.
911static bool isICmpTrue(ICmpInst::Predicate Pred, Value *LHS, Value *RHS,
912 const SimplifyQuery &Q, unsigned MaxRecurse) {
913 Value *V = SimplifyICmpInst(Pred, LHS, RHS, Q, MaxRecurse);
914 Constant *C = dyn_cast_or_null<Constant>(V);
915 return (C && C->isAllOnesValue());
916}
917
918/// Return true if we can simplify X / Y to 0. Remainder can adapt that answer
919/// to simplify X % Y to X.
920static bool isDivZero(Value *X, Value *Y, const SimplifyQuery &Q,
921 unsigned MaxRecurse, bool IsSigned) {
922 // Recursion is always used, so bail out at once if we already hit the limit.
923 if (!MaxRecurse--)
924 return false;
925
926 if (IsSigned) {
927 // |X| / |Y| --> 0
928 //
929 // We require that 1 operand is a simple constant. That could be extended to
930 // 2 variables if we computed the sign bit for each.
931 //
932 // Make sure that a constant is not the minimum signed value because taking
933 // the abs() of that is undefined.
934 Type *Ty = X->getType();
935 const APInt *C;
936 if (match(X, m_APInt(C)) && !C->isMinSignedValue()) {
937 // Is the variable divisor magnitude always greater than the constant
938 // dividend magnitude?
939 // |Y| > |C| --> Y < -abs(C) or Y > abs(C)
940 Constant *PosDividendC = ConstantInt::get(Ty, C->abs());
941 Constant *NegDividendC = ConstantInt::get(Ty, -C->abs());
942 if (isICmpTrue(CmpInst::ICMP_SLT, Y, NegDividendC, Q, MaxRecurse) ||
943 isICmpTrue(CmpInst::ICMP_SGT, Y, PosDividendC, Q, MaxRecurse))
944 return true;
945 }
946 if (match(Y, m_APInt(C))) {
947 // Special-case: we can't take the abs() of a minimum signed value. If
948 // that's the divisor, then all we have to do is prove that the dividend
949 // is also not the minimum signed value.
950 if (C->isMinSignedValue())
951 return isICmpTrue(CmpInst::ICMP_NE, X, Y, Q, MaxRecurse);
952
953 // Is the variable dividend magnitude always less than the constant
954 // divisor magnitude?
955 // |X| < |C| --> X > -abs(C) and X < abs(C)
956 Constant *PosDivisorC = ConstantInt::get(Ty, C->abs());
957 Constant *NegDivisorC = ConstantInt::get(Ty, -C->abs());
958 if (isICmpTrue(CmpInst::ICMP_SGT, X, NegDivisorC, Q, MaxRecurse) &&
959 isICmpTrue(CmpInst::ICMP_SLT, X, PosDivisorC, Q, MaxRecurse))
960 return true;
961 }
962 return false;
963 }
964
965 // IsSigned == false.
966 // Is the dividend unsigned less than the divisor?
967 return isICmpTrue(ICmpInst::ICMP_ULT, X, Y, Q, MaxRecurse);
968}
969
970/// These are simplifications common to SDiv and UDiv.
971static Value *simplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
972 const SimplifyQuery &Q, unsigned MaxRecurse) {
973 if (Constant *C = foldOrCommuteConstant(Opcode, Op0, Op1, Q))
974 return C;
975
976 if (Value *V = simplifyDivRem(Op0, Op1, true))
977 return V;
978
979 bool IsSigned = Opcode == Instruction::SDiv;
980
981 // (X * Y) / Y -> X if the multiplication does not overflow.
982 Value *X;
983 if (match(Op0, m_c_Mul(m_Value(X), m_Specific(Op1)))) {
984 auto *Mul = cast<OverflowingBinaryOperator>(Op0);
985 // If the Mul does not overflow, then we are good to go.
986 if ((IsSigned && Mul->hasNoSignedWrap()) ||
987 (!IsSigned && Mul->hasNoUnsignedWrap()))
988 return X;
989 // If X has the form X = A / Y, then X * Y cannot overflow.
990 if ((IsSigned && match(X, m_SDiv(m_Value(), m_Specific(Op1)))) ||
991 (!IsSigned && match(X, m_UDiv(m_Value(), m_Specific(Op1)))))
992 return X;
993 }
994
995 // (X rem Y) / Y -> 0
996 if ((IsSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
997 (!IsSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
998 return Constant::getNullValue(Op0->getType());
999
1000 // (X /u C1) /u C2 -> 0 if C1 * C2 overflow
1001 ConstantInt *C1, *C2;
1002 if (!IsSigned && match(Op0, m_UDiv(m_Value(X), m_ConstantInt(C1))) &&
1003 match(Op1, m_ConstantInt(C2))) {
1004 bool Overflow;
1005 (void)C1->getValue().umul_ov(C2->getValue(), Overflow);
1006 if (Overflow)
1007 return Constant::getNullValue(Op0->getType());
1008 }
1009
1010 // If the operation is with the result of a select instruction, check whether
1011 // operating on either branch of the select always yields the same value.
1012 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1013 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1014 return V;
1015
1016 // If the operation is with the result of a phi instruction, check whether
1017 // operating on all incoming values of the phi always yields the same value.
1018 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1019 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1020 return V;
1021
1022 if (isDivZero(Op0, Op1, Q, MaxRecurse, IsSigned))
1023 return Constant::getNullValue(Op0->getType());
1024
1025 return nullptr;
1026}
1027
1028/// These are simplifications common to SRem and URem.
1029static Value *simplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
1030 const SimplifyQuery &Q, unsigned MaxRecurse) {
1031 if (Constant *C = foldOrCommuteConstant(Opcode, Op0, Op1, Q))
1032 return C;
1033
1034 if (Value *V = simplifyDivRem(Op0, Op1, false))
1035 return V;
1036
1037 // (X % Y) % Y -> X % Y
1038 if ((Opcode == Instruction::SRem &&
1039 match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
1040 (Opcode == Instruction::URem &&
1041 match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
1042 return Op0;
1043
1044 // (X << Y) % X -> 0
1045 if ((Opcode == Instruction::SRem &&
1046 match(Op0, m_NSWShl(m_Specific(Op1), m_Value()))) ||
1047 (Opcode == Instruction::URem &&
1048 match(Op0, m_NUWShl(m_Specific(Op1), m_Value()))))
1049 return Constant::getNullValue(Op0->getType());
1050
1051 // If the operation is with the result of a select instruction, check whether
1052 // operating on either branch of the select always yields the same value.
1053 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1054 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1055 return V;
1056
1057 // If the operation is with the result of a phi instruction, check whether
1058 // operating on all incoming values of the phi always yields the same value.
1059 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1060 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1061 return V;
1062
1063 // If X / Y == 0, then X % Y == X.
1064 if (isDivZero(Op0, Op1, Q, MaxRecurse, Opcode == Instruction::SRem))
1065 return Op0;
1066
1067 return nullptr;
1068}
1069
1070/// Given operands for an SDiv, see if we can fold the result.
1071/// If not, this returns null.
1072static Value *SimplifySDivInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1073 unsigned MaxRecurse) {
1074 return simplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse);
1075}
1076
1077Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1078 return ::SimplifySDivInst(Op0, Op1, Q, RecursionLimit);
1079}
1080
1081/// Given operands for a UDiv, see if we can fold the result.
1082/// If not, this returns null.
1083static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1084 unsigned MaxRecurse) {
1085 return simplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse);
1086}
1087
1088Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1089 return ::SimplifyUDivInst(Op0, Op1, Q, RecursionLimit);
1090}
1091
1092/// Given operands for an SRem, see if we can fold the result.
1093/// If not, this returns null.
1094static Value *SimplifySRemInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1095 unsigned MaxRecurse) {
1096 return simplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse);
1097}
1098
1099Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1100 return ::SimplifySRemInst(Op0, Op1, Q, RecursionLimit);
1101}
1102
1103/// Given operands for a URem, see if we can fold the result.
1104/// If not, this returns null.
1105static Value *SimplifyURemInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1106 unsigned MaxRecurse) {
1107 return simplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse);
1108}
1109
1110Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1111 return ::SimplifyURemInst(Op0, Op1, Q, RecursionLimit);
1112}
1113
1114/// Returns true if a shift by \c Amount always yields undef.
1115static bool isUndefShift(Value *Amount) {
1116 Constant *C = dyn_cast<Constant>(Amount);
1117 if (!C)
1118 return false;
1119
1120 // X shift by undef -> undef because it may shift by the bitwidth.
1121 if (isa<UndefValue>(C))
1122 return true;
1123
1124 // Shifting by the bitwidth or more is undefined.
1125 if (ConstantInt *CI = dyn_cast<ConstantInt>(C))
1126 if (CI->getValue().getLimitedValue() >=
1127 CI->getType()->getScalarSizeInBits())
1128 return true;
1129
1130 // If all lanes of a vector shift are undefined the whole shift is.
1131 if (isa<ConstantVector>(C) || isa<ConstantDataVector>(C)) {
1132 for (unsigned I = 0, E = C->getType()->getVectorNumElements(); I != E; ++I)
1133 if (!isUndefShift(C->getAggregateElement(I)))
1134 return false;
1135 return true;
1136 }
1137
1138 return false;
1139}
1140
1141/// Given operands for an Shl, LShr or AShr, see if we can fold the result.
1142/// If not, this returns null.
1143static Value *SimplifyShift(Instruction::BinaryOps Opcode, Value *Op0,
1144 Value *Op1, const SimplifyQuery &Q, unsigned MaxRecurse) {
1145 if (Constant *C = foldOrCommuteConstant(Opcode, Op0, Op1, Q))
1146 return C;
1147
1148 // 0 shift by X -> 0
1149 if (match(Op0, m_Zero()))
1150 return Op0;
1151
1152 // X shift by 0 -> X
1153 if (match(Op1, m_Zero()))
1154 return Op0;
1155
1156 // Fold undefined shifts.
1157 if (isUndefShift(Op1))
1158 return UndefValue::get(Op0->getType());
1159
1160 // If the operation is with the result of a select instruction, check whether
1161 // operating on either branch of the select always yields the same value.
1162 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1163 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1164 return V;
1165
1166 // If the operation is with the result of a phi instruction, check whether
1167 // operating on all incoming values of the phi always yields the same value.
1168 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1169 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1170 return V;
1171
1172 // If any bits in the shift amount make that value greater than or equal to
1173 // the number of bits in the type, the shift is undefined.
1174 KnownBits Known = computeKnownBits(Op1, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
1175 if (Known.One.getLimitedValue() >= Known.getBitWidth())
1176 return UndefValue::get(Op0->getType());
1177
1178 // If all valid bits in the shift amount are known zero, the first operand is
1179 // unchanged.
1180 unsigned NumValidShiftBits = Log2_32_Ceil(Known.getBitWidth());
1181 if (Known.countMinTrailingZeros() >= NumValidShiftBits)
1182 return Op0;
1183
1184 return nullptr;
1185}
1186
1187/// \brief Given operands for an Shl, LShr or AShr, see if we can
1188/// fold the result. If not, this returns null.
1189static Value *SimplifyRightShift(Instruction::BinaryOps Opcode, Value *Op0,
1190 Value *Op1, bool isExact, const SimplifyQuery &Q,
1191 unsigned MaxRecurse) {
1192 if (Value *V = SimplifyShift(Opcode, Op0, Op1, Q, MaxRecurse))
1193 return V;
1194
1195 // X >> X -> 0
1196 if (Op0 == Op1)
1197 return Constant::getNullValue(Op0->getType());
1198
1199 // undef >> X -> 0
1200 // undef >> X -> undef (if it's exact)
1201 if (match(Op0, m_Undef()))
1202 return isExact ? Op0 : Constant::getNullValue(Op0->getType());
1203
1204 // The low bit cannot be shifted out of an exact shift if it is set.
1205 if (isExact) {
1206 KnownBits Op0Known = computeKnownBits(Op0, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT);
1207 if (Op0Known.One[0])
1208 return Op0;
1209 }
1210
1211 return nullptr;
1212}
1213
1214/// Given operands for an Shl, see if we can fold the result.
1215/// If not, this returns null.
1216static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1217 const SimplifyQuery &Q, unsigned MaxRecurse) {
1218 if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
1219 return V;
1220
1221 // undef << X -> 0
1222 // undef << X -> undef if (if it's NSW/NUW)
1223 if (match(Op0, m_Undef()))
1224 return isNSW || isNUW ? Op0 : Constant::getNullValue(Op0->getType());
1225
1226 // (X >> A) << A -> X
1227 Value *X;
1228 if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
1229 return X;
1230 return nullptr;
1231}
1232
1233Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1234 const SimplifyQuery &Q) {
1235 return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Q, RecursionLimit);
1236}
1237
1238/// Given operands for an LShr, see if we can fold the result.
1239/// If not, this returns null.
1240static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1241 const SimplifyQuery &Q, unsigned MaxRecurse) {
1242 if (Value *V = SimplifyRightShift(Instruction::LShr, Op0, Op1, isExact, Q,
1243 MaxRecurse))
1244 return V;
1245
1246 // (X << A) >> A -> X
1247 Value *X;
1248 if (match(Op0, m_NUWShl(m_Value(X), m_Specific(Op1))))
1249 return X;
1250
1251 return nullptr;
1252}
1253
1254Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1255 const SimplifyQuery &Q) {
1256 return ::SimplifyLShrInst(Op0, Op1, isExact, Q, RecursionLimit);
1257}
1258
1259/// Given operands for an AShr, see if we can fold the result.
1260/// If not, this returns null.
1261static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1262 const SimplifyQuery &Q, unsigned MaxRecurse) {
1263 if (Value *V = SimplifyRightShift(Instruction::AShr, Op0, Op1, isExact, Q,
1264 MaxRecurse))
1265 return V;
1266
1267 // all ones >>a X -> -1
1268 // Do not return Op0 because it may contain undef elements if it's a vector.
1269 if (match(Op0, m_AllOnes()))
1270 return Constant::getAllOnesValue(Op0->getType());
1271
1272 // (X << A) >> A -> X
1273 Value *X;
1274 if (match(Op0, m_NSWShl(m_Value(X), m_Specific(Op1))))
1275 return X;
1276
1277 // Arithmetic shifting an all-sign-bit value is a no-op.
1278 unsigned NumSignBits = ComputeNumSignBits(Op0, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
1279 if (NumSignBits == Op0->getType()->getScalarSizeInBits())
1280 return Op0;
1281
1282 return nullptr;
1283}
1284
1285Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1286 const SimplifyQuery &Q) {
1287 return ::SimplifyAShrInst(Op0, Op1, isExact, Q, RecursionLimit);
1288}
1289
1290/// Commuted variants are assumed to be handled by calling this function again
1291/// with the parameters swapped.
1292static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
1293 ICmpInst *UnsignedICmp, bool IsAnd) {
1294 Value *X, *Y;
1295
1296 ICmpInst::Predicate EqPred;
1297 if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) ||
1298 !ICmpInst::isEquality(EqPred))
1299 return nullptr;
1300
1301 ICmpInst::Predicate UnsignedPred;
1302 if (match(UnsignedICmp, m_ICmp(UnsignedPred, m_Value(X), m_Specific(Y))) &&
1303 ICmpInst::isUnsigned(UnsignedPred))
1304 ;
1305 else if (match(UnsignedICmp,
1306 m_ICmp(UnsignedPred, m_Value(Y), m_Specific(X))) &&
1307 ICmpInst::isUnsigned(UnsignedPred))
1308 UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred);
1309 else
1310 return nullptr;
1311
1312 // X < Y && Y != 0 --> X < Y
1313 // X < Y || Y != 0 --> Y != 0
1314 if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE)
1315 return IsAnd ? UnsignedICmp : ZeroICmp;
1316
1317 // X >= Y || Y != 0 --> true
1318 // X >= Y || Y == 0 --> X >= Y
1319 if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd) {
1320 if (EqPred == ICmpInst::ICMP_NE)
1321 return getTrue(UnsignedICmp->getType());
1322 return UnsignedICmp;
1323 }
1324
1325 // X < Y && Y == 0 --> false
1326 if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_EQ &&
1327 IsAnd)
1328 return getFalse(UnsignedICmp->getType());
1329
1330 return nullptr;
1331}
1332
1333/// Commuted variants are assumed to be handled by calling this function again
1334/// with the parameters swapped.
1335static Value *simplifyAndOfICmpsWithSameOperands(ICmpInst *Op0, ICmpInst *Op1) {
1336 ICmpInst::Predicate Pred0, Pred1;
1337 Value *A ,*B;
1338 if (!match(Op0, m_ICmp(Pred0, m_Value(A), m_Value(B))) ||
1339 !match(Op1, m_ICmp(Pred1, m_Specific(A), m_Specific(B))))
1340 return nullptr;
1341
1342 // We have (icmp Pred0, A, B) & (icmp Pred1, A, B).
1343 // If Op1 is always implied true by Op0, then Op0 is a subset of Op1, and we
1344 // can eliminate Op1 from this 'and'.
1345 if (ICmpInst::isImpliedTrueByMatchingCmp(Pred0, Pred1))
1346 return Op0;
1347
1348 // Check for any combination of predicates that are guaranteed to be disjoint.
1349 if ((Pred0 == ICmpInst::getInversePredicate(Pred1)) ||
1350 (Pred0 == ICmpInst::ICMP_EQ && ICmpInst::isFalseWhenEqual(Pred1)) ||
1351 (Pred0 == ICmpInst::ICMP_SLT && Pred1 == ICmpInst::ICMP_SGT) ||
1352 (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_UGT))
1353 return getFalse(Op0->getType());
1354
1355 return nullptr;
1356}
1357
1358/// Commuted variants are assumed to be handled by calling this function again
1359/// with the parameters swapped.
1360static Value *simplifyOrOfICmpsWithSameOperands(ICmpInst *Op0, ICmpInst *Op1) {
1361 ICmpInst::Predicate Pred0, Pred1;
1362 Value *A ,*B;
1363 if (!match(Op0, m_ICmp(Pred0, m_Value(A), m_Value(B))) ||
1364 !match(Op1, m_ICmp(Pred1, m_Specific(A), m_Specific(B))))
1365 return nullptr;
1366
1367 // We have (icmp Pred0, A, B) | (icmp Pred1, A, B).
1368 // If Op1 is always implied true by Op0, then Op0 is a subset of Op1, and we
1369 // can eliminate Op0 from this 'or'.
1370 if (ICmpInst::isImpliedTrueByMatchingCmp(Pred0, Pred1))
1371 return Op1;
1372
1373 // Check for any combination of predicates that cover the entire range of
1374 // possibilities.
1375 if ((Pred0 == ICmpInst::getInversePredicate(Pred1)) ||
1376 (Pred0 == ICmpInst::ICMP_NE && ICmpInst::isTrueWhenEqual(Pred1)) ||
1377 (Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGE) ||
1378 (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGE))
1379 return getTrue(Op0->getType());
1380
1381 return nullptr;
1382}
1383
1384/// Test if a pair of compares with a shared operand and 2 constants has an
1385/// empty set intersection, full set union, or if one compare is a superset of
1386/// the other.
1387static Value *simplifyAndOrOfICmpsWithConstants(ICmpInst *Cmp0, ICmpInst *Cmp1,
1388 bool IsAnd) {
1389 // Look for this pattern: {and/or} (icmp X, C0), (icmp X, C1)).
1390 if (Cmp0->getOperand(0) != Cmp1->getOperand(0))
1391 return nullptr;
1392
1393 const APInt *C0, *C1;
1394 if (!match(Cmp0->getOperand(1), m_APInt(C0)) ||
1395 !match(Cmp1->getOperand(1), m_APInt(C1)))
1396 return nullptr;
1397
1398 auto Range0 = ConstantRange::makeExactICmpRegion(Cmp0->getPredicate(), *C0);
1399 auto Range1 = ConstantRange::makeExactICmpRegion(Cmp1->getPredicate(), *C1);
1400
1401 // For and-of-compares, check if the intersection is empty:
1402 // (icmp X, C0) && (icmp X, C1) --> empty set --> false
1403 if (IsAnd && Range0.intersectWith(Range1).isEmptySet())
1404 return getFalse(Cmp0->getType());
1405
1406 // For or-of-compares, check if the union is full:
1407 // (icmp X, C0) || (icmp X, C1) --> full set --> true
1408 if (!IsAnd && Range0.unionWith(Range1).isFullSet())
1409 return getTrue(Cmp0->getType());
1410
1411 // Is one range a superset of the other?
1412 // If this is and-of-compares, take the smaller set:
1413 // (icmp sgt X, 4) && (icmp sgt X, 42) --> icmp sgt X, 42
1414 // If this is or-of-compares, take the larger set:
1415 // (icmp sgt X, 4) || (icmp sgt X, 42) --> icmp sgt X, 4
1416 if (Range0.contains(Range1))
1417 return IsAnd ? Cmp1 : Cmp0;
1418 if (Range1.contains(Range0))
1419 return IsAnd ? Cmp0 : Cmp1;
1420
1421 return nullptr;
1422}
1423
1424static Value *simplifyAndOrOfICmpsWithZero(ICmpInst *Cmp0, ICmpInst *Cmp1,
1425 bool IsAnd) {
1426 ICmpInst::Predicate P0 = Cmp0->getPredicate(), P1 = Cmp1->getPredicate();
1427 if (!match(Cmp0->getOperand(1), m_Zero()) ||
1428 !match(Cmp1->getOperand(1), m_Zero()) || P0 != P1)
1429 return nullptr;
1430
1431 if ((IsAnd && P0 != ICmpInst::ICMP_NE) || (!IsAnd && P1 != ICmpInst::ICMP_EQ))
1432 return nullptr;
1433
1434 // We have either "(X == 0 || Y == 0)" or "(X != 0 && Y != 0)".
1435 Value *X = Cmp0->getOperand(0);
1436 Value *Y = Cmp1->getOperand(0);
1437
1438 // If one of the compares is a masked version of a (not) null check, then
1439 // that compare implies the other, so we eliminate the other. Optionally, look
1440 // through a pointer-to-int cast to match a null check of a pointer type.
1441
1442 // (X == 0) || (([ptrtoint] X & ?) == 0) --> ([ptrtoint] X & ?) == 0
1443 // (X == 0) || ((? & [ptrtoint] X) == 0) --> (? & [ptrtoint] X) == 0
1444 // (X != 0) && (([ptrtoint] X & ?) != 0) --> ([ptrtoint] X & ?) != 0
1445 // (X != 0) && ((? & [ptrtoint] X) != 0) --> (? & [ptrtoint] X) != 0
1446 if (match(Y, m_c_And(m_Specific(X), m_Value())) ||
1447 match(Y, m_c_And(m_PtrToInt(m_Specific(X)), m_Value())))
1448 return Cmp1;
1449
1450 // (([ptrtoint] Y & ?) == 0) || (Y == 0) --> ([ptrtoint] Y & ?) == 0
1451 // ((? & [ptrtoint] Y) == 0) || (Y == 0) --> (? & [ptrtoint] Y) == 0
1452 // (([ptrtoint] Y & ?) != 0) && (Y != 0) --> ([ptrtoint] Y & ?) != 0
1453 // ((? & [ptrtoint] Y) != 0) && (Y != 0) --> (? & [ptrtoint] Y) != 0
1454 if (match(X, m_c_And(m_Specific(Y), m_Value())) ||
1455 match(X, m_c_And(m_PtrToInt(m_Specific(Y)), m_Value())))
1456 return Cmp0;
1457
1458 return nullptr;
1459}
1460
1461static Value *simplifyAndOfICmpsWithAdd(ICmpInst *Op0, ICmpInst *Op1) {
1462 // (icmp (add V, C0), C1) & (icmp V, C0)
1463 ICmpInst::Predicate Pred0, Pred1;
1464 const APInt *C0, *C1;
1465 Value *V;
1466 if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_APInt(C0)), m_APInt(C1))))
1467 return nullptr;
1468
1469 if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Value())))
1470 return nullptr;
1471
1472 auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
1473 if (AddInst->getOperand(1) != Op1->getOperand(1))
1474 return nullptr;
1475
1476 Type *ITy = Op0->getType();
1477 bool isNSW = AddInst->hasNoSignedWrap();
1478 bool isNUW = AddInst->hasNoUnsignedWrap();
1479
1480 const APInt Delta = *C1 - *C0;
1481 if (C0->isStrictlyPositive()) {
1482 if (Delta == 2) {
1483 if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_SGT)
1484 return getFalse(ITy);
1485 if (Pred0 == ICmpInst::ICMP_SLT && Pred1 == ICmpInst::ICMP_SGT && isNSW)
1486 return getFalse(ITy);
1487 }
1488 if (Delta == 1) {
1489 if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_SGT)
1490 return getFalse(ITy);
1491 if (Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGT && isNSW)
1492 return getFalse(ITy);
1493 }
1494 }
1495 if (C0->getBoolValue() && isNUW) {
1496 if (Delta == 2)
1497 if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_UGT)
1498 return getFalse(ITy);
1499 if (Delta == 1)
1500 if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGT)
1501 return getFalse(ITy);
1502 }
1503
1504 return nullptr;
1505}
1506
1507static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
1508 if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
1509 return X;
1510 if (Value *X = simplifyUnsignedRangeCheck(Op1, Op0, /*IsAnd=*/true))
1511 return X;
1512
1513 if (Value *X = simplifyAndOfICmpsWithSameOperands(Op0, Op1))
1514 return X;
1515 if (Value *X = simplifyAndOfICmpsWithSameOperands(Op1, Op0))
1516 return X;
1517
1518 if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, true))
1519 return X;
1520
1521 if (Value *X = simplifyAndOrOfICmpsWithZero(Op0, Op1, true))
1522 return X;
1523
1524 if (Value *X = simplifyAndOfICmpsWithAdd(Op0, Op1))
1525 return X;
1526 if (Value *X = simplifyAndOfICmpsWithAdd(Op1, Op0))
1527 return X;
1528
1529 return nullptr;
1530}
1531
1532static Value *simplifyOrOfICmpsWithAdd(ICmpInst *Op0, ICmpInst *Op1) {
1533 // (icmp (add V, C0), C1) | (icmp V, C0)
1534 ICmpInst::Predicate Pred0, Pred1;
1535 const APInt *C0, *C1;
1536 Value *V;
1537 if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_APInt(C0)), m_APInt(C1))))
1538 return nullptr;
1539
1540 if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Value())))
1541 return nullptr;
1542
1543 auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
1544 if (AddInst->getOperand(1) != Op1->getOperand(1))
1545 return nullptr;
1546
1547 Type *ITy = Op0->getType();
1548 bool isNSW = AddInst->hasNoSignedWrap();
1549 bool isNUW = AddInst->hasNoUnsignedWrap();
1550
1551 const APInt Delta = *C1 - *C0;
1552 if (C0->isStrictlyPositive()) {
1553 if (Delta == 2) {
1554 if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_SLE)
1555 return getTrue(ITy);
1556 if (Pred0 == ICmpInst::ICMP_SGE && Pred1 == ICmpInst::ICMP_SLE && isNSW)
1557 return getTrue(ITy);
1558 }
1559 if (Delta == 1) {
1560 if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_SLE)
1561 return getTrue(ITy);
1562 if (Pred0 == ICmpInst::ICMP_SGT && Pred1 == ICmpInst::ICMP_SLE && isNSW)
1563 return getTrue(ITy);
1564 }
1565 }
1566 if (C0->getBoolValue() && isNUW) {
1567 if (Delta == 2)
1568 if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_ULE)
1569 return getTrue(ITy);
1570 if (Delta == 1)
1571 if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE)
1572 return getTrue(ITy);
1573 }
1574
1575 return nullptr;
1576}
1577
1578static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
1579 if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
1580 return X;
1581 if (Value *X = simplifyUnsignedRangeCheck(Op1, Op0, /*IsAnd=*/false))
1582 return X;
1583
1584 if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
1585 return X;
1586 if (Value *X = simplifyOrOfICmpsWithSameOperands(Op1, Op0))
1587 return X;
1588
1589 if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, false))
1590 return X;
1591
1592 if (Value *X = simplifyAndOrOfICmpsWithZero(Op0, Op1, false))
1593 return X;
1594
1595 if (Value *X = simplifyOrOfICmpsWithAdd(Op0, Op1))
1596 return X;
1597 if (Value *X = simplifyOrOfICmpsWithAdd(Op1, Op0))
1598 return X;
1599
1600 return nullptr;
1601}
1602
1603static Value *simplifyAndOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS, bool IsAnd) {
1604 Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
1605 Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
1606 if (LHS0->getType() != RHS0->getType())
1607 return nullptr;
1608
1609 FCmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
1610 if ((PredL == FCmpInst::FCMP_ORD && PredR == FCmpInst::FCMP_ORD && IsAnd) ||
1611 (PredL == FCmpInst::FCMP_UNO && PredR == FCmpInst::FCMP_UNO && !IsAnd)) {
1612 // (fcmp ord NNAN, X) & (fcmp ord X, Y) --> fcmp ord X, Y
1613 // (fcmp ord NNAN, X) & (fcmp ord Y, X) --> fcmp ord Y, X
1614 // (fcmp ord X, NNAN) & (fcmp ord X, Y) --> fcmp ord X, Y
1615 // (fcmp ord X, NNAN) & (fcmp ord Y, X) --> fcmp ord Y, X
1616 // (fcmp uno NNAN, X) | (fcmp uno X, Y) --> fcmp uno X, Y
1617 // (fcmp uno NNAN, X) | (fcmp uno Y, X) --> fcmp uno Y, X
1618 // (fcmp uno X, NNAN) | (fcmp uno X, Y) --> fcmp uno X, Y
1619 // (fcmp uno X, NNAN) | (fcmp uno Y, X) --> fcmp uno Y, X
1620 if ((isKnownNeverNaN(LHS0) && (LHS1 == RHS0 || LHS1 == RHS1)) ||
1621 (isKnownNeverNaN(LHS1) && (LHS0 == RHS0 || LHS0 == RHS1)))
1622 return RHS;
1623
1624 // (fcmp ord X, Y) & (fcmp ord NNAN, X) --> fcmp ord X, Y
1625 // (fcmp ord Y, X) & (fcmp ord NNAN, X) --> fcmp ord Y, X
1626 // (fcmp ord X, Y) & (fcmp ord X, NNAN) --> fcmp ord X, Y
1627 // (fcmp ord Y, X) & (fcmp ord X, NNAN) --> fcmp ord Y, X
1628 // (fcmp uno X, Y) | (fcmp uno NNAN, X) --> fcmp uno X, Y
1629 // (fcmp uno Y, X) | (fcmp uno NNAN, X) --> fcmp uno Y, X
1630 // (fcmp uno X, Y) | (fcmp uno X, NNAN) --> fcmp uno X, Y
1631 // (fcmp uno Y, X) | (fcmp uno X, NNAN) --> fcmp uno Y, X
1632 if ((isKnownNeverNaN(RHS0) && (RHS1 == LHS0 || RHS1 == LHS1)) ||
1633 (isKnownNeverNaN(RHS1) && (RHS0 == LHS0 || RHS0 == LHS1)))
1634 return LHS;
1635 }
1636
1637 return nullptr;
1638}
1639
1640static Value *simplifyAndOrOfCmps(Value *Op0, Value *Op1, bool IsAnd) {
1641 // Look through casts of the 'and' operands to find compares.
1642 auto *Cast0 = dyn_cast<CastInst>(Op0);
1643 auto *Cast1 = dyn_cast<CastInst>(Op1);
1644 if (Cast0 && Cast1 && Cast0->getOpcode() == Cast1->getOpcode() &&
1645 Cast0->getSrcTy() == Cast1->getSrcTy()) {
1646 Op0 = Cast0->getOperand(0);
1647 Op1 = Cast1->getOperand(0);
1648 }
1649
1650 Value *V = nullptr;
1651 auto *ICmp0 = dyn_cast<ICmpInst>(Op0);
1652 auto *ICmp1 = dyn_cast<ICmpInst>(Op1);
1653 if (ICmp0 && ICmp1)
1654 V = IsAnd ? simplifyAndOfICmps(ICmp0, ICmp1) :
1655 simplifyOrOfICmps(ICmp0, ICmp1);
1656
1657 auto *FCmp0 = dyn_cast<FCmpInst>(Op0);
1658 auto *FCmp1 = dyn_cast<FCmpInst>(Op1);
1659 if (FCmp0 && FCmp1)
1660 V = simplifyAndOrOfFCmps(FCmp0, FCmp1, IsAnd);
1661
1662 if (!V)
1663 return nullptr;
1664 if (!Cast0)
1665 return V;
1666
1667 // If we looked through casts, we can only handle a constant simplification
1668 // because we are not allowed to create a cast instruction here.
1669 if (auto *C = dyn_cast<Constant>(V))
1670 return ConstantExpr::getCast(Cast0->getOpcode(), C, Cast0->getType());
1671
1672 return nullptr;
1673}
1674
1675/// Given operands for an And, see if we can fold the result.
1676/// If not, this returns null.
1677static Value *SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1678 unsigned MaxRecurse) {
1679 if (Constant *C = foldOrCommuteConstant(Instruction::And, Op0, Op1, Q))
1680 return C;
1681
1682 // X & undef -> 0
1683 if (match(Op1, m_Undef()))
1684 return Constant::getNullValue(Op0->getType());
1685
1686 // X & X = X
1687 if (Op0 == Op1)
1688 return Op0;
1689
1690 // X & 0 = 0
1691 if (match(Op1, m_Zero()))
1692 return Op1;
1693
1694 // X & -1 = X
1695 if (match(Op1, m_AllOnes()))
1696 return Op0;
1697
1698 // A & ~A = ~A & A = 0
1699 if (match(Op0, m_Not(m_Specific(Op1))) ||
1700 match(Op1, m_Not(m_Specific(Op0))))
1701 return Constant::getNullValue(Op0->getType());
1702
1703 // (A | ?) & A = A
1704 if (match(Op0, m_c_Or(m_Specific(Op1), m_Value())))
1705 return Op1;
1706
1707 // A & (A | ?) = A
1708 if (match(Op1, m_c_Or(m_Specific(Op0), m_Value())))
1709 return Op0;
1710
1711 // A mask that only clears known zeros of a shifted value is a no-op.
1712 Value *X;
1713 const APInt *Mask;
1714 const APInt *ShAmt;
1715 if (match(Op1, m_APInt(Mask))) {
1716 // If all bits in the inverted and shifted mask are clear:
1717 // and (shl X, ShAmt), Mask --> shl X, ShAmt
1718 if (match(Op0, m_Shl(m_Value(X), m_APInt(ShAmt))) &&
1719 (~(*Mask)).lshr(*ShAmt).isNullValue())
1720 return Op0;
1721
1722 // If all bits in the inverted and shifted mask are clear:
1723 // and (lshr X, ShAmt), Mask --> lshr X, ShAmt
1724 if (match(Op0, m_LShr(m_Value(X), m_APInt(ShAmt))) &&
1725 (~(*Mask)).shl(*ShAmt).isNullValue())
1726 return Op0;
1727 }
1728
1729 // A & (-A) = A if A is a power of two or zero.
1730 if (match(Op0, m_Neg(m_Specific(Op1))) ||
1731 match(Op1, m_Neg(m_Specific(Op0)))) {
1732 if (isKnownToBeAPowerOfTwo(Op0, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI,
1733 Q.DT))
1734 return Op0;
1735 if (isKnownToBeAPowerOfTwo(Op1, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI,
1736 Q.DT))
1737 return Op1;
1738 }
1739
1740 if (Value *V = simplifyAndOrOfCmps(Op0, Op1, true))
1741 return V;
1742
1743 // Try some generic simplifications for associative operations.
1744 if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q,
1745 MaxRecurse))
1746 return V;
1747
1748 // And distributes over Or. Try some generic simplifications based on this.
1749 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or,
1750 Q, MaxRecurse))
1751 return V;
1752
1753 // And distributes over Xor. Try some generic simplifications based on this.
1754 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor,
1755 Q, MaxRecurse))
1756 return V;
1757
1758 // If the operation is with the result of a select instruction, check whether
1759 // operating on either branch of the select always yields the same value.
1760 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1761 if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q,
1762 MaxRecurse))
1763 return V;
1764
1765 // If the operation is with the result of a phi instruction, check whether
1766 // operating on all incoming values of the phi always yields the same value.
1767 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1768 if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q,
1769 MaxRecurse))
1770 return V;
1771
1772 return nullptr;
1773}
1774
1775Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1776 return ::SimplifyAndInst(Op0, Op1, Q, RecursionLimit);
1777}
1778
1779/// Given operands for an Or, see if we can fold the result.
1780/// If not, this returns null.
1781static Value *SimplifyOrInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1782 unsigned MaxRecurse) {
1783 if (Constant *C = foldOrCommuteConstant(Instruction::Or, Op0, Op1, Q))
1784 return C;
1785
1786 // X | undef -> -1
1787 // X | -1 = -1
1788 // Do not return Op1 because it may contain undef elements if it's a vector.
1789 if (match(Op1, m_Undef()) || match(Op1, m_AllOnes()))
1790 return Constant::getAllOnesValue(Op0->getType());
1791
1792 // X | X = X
1793 // X | 0 = X
1794 if (Op0 == Op1 || match(Op1, m_Zero()))
1795 return Op0;
1796
1797 // A | ~A = ~A | A = -1
1798 if (match(Op0, m_Not(m_Specific(Op1))) ||
1799 match(Op1, m_Not(m_Specific(Op0))))
1800 return Constant::getAllOnesValue(Op0->getType());
1801
1802 // (A & ?) | A = A
1803 if (match(Op0, m_c_And(m_Specific(Op1), m_Value())))
1804 return Op1;
1805
1806 // A | (A & ?) = A
1807 if (match(Op1, m_c_And(m_Specific(Op0), m_Value())))
1808 return Op0;
1809
1810 // ~(A & ?) | A = -1
1811 if (match(Op0, m_Not(m_c_And(m_Specific(Op1), m_Value()))))
1812 return Constant::getAllOnesValue(Op1->getType());
1813
1814 // A | ~(A & ?) = -1
1815 if (match(Op1, m_Not(m_c_And(m_Specific(Op1), m_Value()))))
1816 return Constant::getAllOnesValue(Op0->getType());
1817
1818 Value *A, *B;
1819 // (A & ~B) | (A ^ B) -> (A ^ B)
1820 // (~B & A) | (A ^ B) -> (A ^ B)
1821 // (A & ~B) | (B ^ A) -> (B ^ A)
1822 // (~B & A) | (B ^ A) -> (B ^ A)
1823 if (match(Op1, m_Xor(m_Value(A), m_Value(B))) &&
1824 (match(Op0, m_c_And(m_Specific(A), m_Not(m_Specific(B)))) ||
1825 match(Op0, m_c_And(m_Not(m_Specific(A)), m_Specific(B)))))
1826 return Op1;
1827
1828 // Commute the 'or' operands.
1829 // (A ^ B) | (A & ~B) -> (A ^ B)
1830 // (A ^ B) | (~B & A) -> (A ^ B)
1831 // (B ^ A) | (A & ~B) -> (B ^ A)
1832 // (B ^ A) | (~B & A) -> (B ^ A)
1833 if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
1834 (match(Op1, m_c_And(m_Specific(A), m_Not(m_Specific(B)))) ||
1835 match(Op1, m_c_And(m_Not(m_Specific(A)), m_Specific(B)))))
1836 return Op0;
1837
1838 // (A & B) | (~A ^ B) -> (~A ^ B)
1839 // (B & A) | (~A ^ B) -> (~A ^ B)
1840 // (A & B) | (B ^ ~A) -> (B ^ ~A)
1841 // (B & A) | (B ^ ~A) -> (B ^ ~A)
1842 if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1843 (match(Op1, m_c_Xor(m_Specific(A), m_Not(m_Specific(B)))) ||
1844 match(Op1, m_c_Xor(m_Not(m_Specific(A)), m_Specific(B)))))
1845 return Op1;
1846
1847 // (~A ^ B) | (A & B) -> (~A ^ B)
1848 // (~A ^ B) | (B & A) -> (~A ^ B)
1849 // (B ^ ~A) | (A & B) -> (B ^ ~A)
1850 // (B ^ ~A) | (B & A) -> (B ^ ~A)
1851 if (match(Op1, m_And(m_Value(A), m_Value(B))) &&
1852 (match(Op0, m_c_Xor(m_Specific(A), m_Not(m_Specific(B)))) ||
1853 match(Op0, m_c_Xor(m_Not(m_Specific(A)), m_Specific(B)))))
1854 return Op0;
1855
1856 if (Value *V = simplifyAndOrOfCmps(Op0, Op1, false))
1857 return V;
1858
1859 // Try some generic simplifications for associative operations.
1860 if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q,
1861 MaxRecurse))
1862 return V;
1863
1864 // Or distributes over And. Try some generic simplifications based on this.
1865 if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q,
1866 MaxRecurse))
1867 return V;
1868
1869 // If the operation is with the result of a select instruction, check whether
1870 // operating on either branch of the select always yields the same value.
1871 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1872 if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q,
1873 MaxRecurse))
1874 return V;
1875
1876 // (A & C1)|(B & C2)
1877 const APInt *C1, *C2;
1878 if (match(Op0, m_And(m_Value(A), m_APInt(C1))) &&
1879 match(Op1, m_And(m_Value(B), m_APInt(C2)))) {
1880 if (*C1 == ~*C2) {
1881 // (A & C1)|(B & C2)
1882 // If we have: ((V + N) & C1) | (V & C2)
1883 // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
1884 // replace with V+N.
1885 Value *N;
1886 if (C2->isMask() && // C2 == 0+1+
1887 match(A, m_c_Add(m_Specific(B), m_Value(N)))) {
1888 // Add commutes, try both ways.
1889 if (MaskedValueIsZero(N, *C2, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
1890 return A;
1891 }
1892 // Or commutes, try both ways.
1893 if (C1->isMask() &&
1894 match(B, m_c_Add(m_Specific(A), m_Value(N)))) {
1895 // Add commutes, try both ways.
1896 if (MaskedValueIsZero(N, *C1, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
1897 return B;
1898 }
1899 }
1900 }
1901
1902 // If the operation is with the result of a phi instruction, check whether
1903 // operating on all incoming values of the phi always yields the same value.
1904 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1905 if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
1906 return V;
1907
1908 return nullptr;
1909}
1910
1911Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1912 return ::SimplifyOrInst(Op0, Op1, Q, RecursionLimit);
1913}
1914
1915/// Given operands for a Xor, see if we can fold the result.
1916/// If not, this returns null.
1917static Value *SimplifyXorInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
1918 unsigned MaxRecurse) {
1919 if (Constant *C = foldOrCommuteConstant(Instruction::Xor, Op0, Op1, Q))
1920 return C;
1921
1922 // A ^ undef -> undef
1923 if (match(Op1, m_Undef()))
1924 return Op1;
1925
1926 // A ^ 0 = A
1927 if (match(Op1, m_Zero()))
1928 return Op0;
1929
1930 // A ^ A = 0
1931 if (Op0 == Op1)
1932 return Constant::getNullValue(Op0->getType());
1933
1934 // A ^ ~A = ~A ^ A = -1
1935 if (match(Op0, m_Not(m_Specific(Op1))) ||
1936 match(Op1, m_Not(m_Specific(Op0))))
1937 return Constant::getAllOnesValue(Op0->getType());
1938
1939 // Try some generic simplifications for associative operations.
1940 if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q,
1941 MaxRecurse))
1942 return V;
1943
1944 // Threading Xor over selects and phi nodes is pointless, so don't bother.
1945 // Threading over the select in "A ^ select(cond, B, C)" means evaluating
1946 // "A^B" and "A^C" and seeing if they are equal; but they are equal if and
1947 // only if B and C are equal. If B and C are equal then (since we assume
1948 // that operands have already been simplified) "select(cond, B, C)" should
1949 // have been simplified to the common value of B and C already. Analysing
1950 // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
1951 // for threading over phi nodes.
1952
1953 return nullptr;
1954}
1955
1956Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
1957 return ::SimplifyXorInst(Op0, Op1, Q, RecursionLimit);
1958}
1959
1960
1961static Type *GetCompareTy(Value *Op) {
1962 return CmpInst::makeCmpResultType(Op->getType());
1963}
1964
1965/// Rummage around inside V looking for something equivalent to the comparison
1966/// "LHS Pred RHS". Return such a value if found, otherwise return null.
1967/// Helper function for analyzing max/min idioms.
1968static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
1969 Value *LHS, Value *RHS) {
1970 SelectInst *SI = dyn_cast<SelectInst>(V);
1971 if (!SI)
1972 return nullptr;
1973 CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
1974 if (!Cmp)
1975 return nullptr;
1976 Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
1977 if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
1978 return Cmp;
1979 if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
1980 LHS == CmpRHS && RHS == CmpLHS)
1981 return Cmp;
1982 return nullptr;
1983}
1984
1985// A significant optimization not implemented here is assuming that alloca
1986// addresses are not equal to incoming argument values. They don't *alias*,
1987// as we say, but that doesn't mean they aren't equal, so we take a
1988// conservative approach.
1989//
1990// This is inspired in part by C++11 5.10p1:
1991// "Two pointers of the same type compare equal if and only if they are both
1992// null, both point to the same function, or both represent the same
1993// address."
1994//
1995// This is pretty permissive.
1996//
1997// It's also partly due to C11 6.5.9p6:
1998// "Two pointers compare equal if and only if both are null pointers, both are
1999// pointers to the same object (including a pointer to an object and a
2000// subobject at its beginning) or function, both are pointers to one past the
2001// last element of the same array object, or one is a pointer to one past the
2002// end of one array object and the other is a pointer to the start of a
2003// different array object that happens to immediately follow the first array
2004// object in the address space.)
2005//
2006// C11's version is more restrictive, however there's no reason why an argument
2007// couldn't be a one-past-the-end value for a stack object in the caller and be
2008// equal to the beginning of a stack object in the callee.
2009//
2010// If the C and C++ standards are ever made sufficiently restrictive in this
2011// area, it may be possible to update LLVM's semantics accordingly and reinstate
2012// this optimization.
2013static Constant *
2014computePointerICmp(const DataLayout &DL, const TargetLibraryInfo *TLI,
2015 const DominatorTree *DT, CmpInst::Predicate Pred,
2016 AssumptionCache *AC, const Instruction *CxtI,
2017 Value *LHS, Value *RHS) {
2018 // First, skip past any trivial no-ops.
2019 LHS = LHS->stripPointerCasts();
2020 RHS = RHS->stripPointerCasts();
2021
2022 // A non-null pointer is not equal to a null pointer.
2023 if (llvm::isKnownNonZero(LHS, DL) && isa<ConstantPointerNull>(RHS) &&
2024 (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE))
2025 return ConstantInt::get(GetCompareTy(LHS),
2026 !CmpInst::isTrueWhenEqual(Pred));
2027
2028 // We can only fold certain predicates on pointer comparisons.
2029 switch (Pred) {
2030 default:
2031 return nullptr;
2032
2033 // Equality comaprisons are easy to fold.
2034 case CmpInst::ICMP_EQ:
2035 case CmpInst::ICMP_NE:
2036 break;
2037
2038 // We can only handle unsigned relational comparisons because 'inbounds' on
2039 // a GEP only protects against unsigned wrapping.
2040 case CmpInst::ICMP_UGT:
2041 case CmpInst::ICMP_UGE:
2042 case CmpInst::ICMP_ULT:
2043 case CmpInst::ICMP_ULE:
2044 // However, we have to switch them to their signed variants to handle
2045 // negative indices from the base pointer.
2046 Pred = ICmpInst::getSignedPredicate(Pred);
2047 break;
2048 }
2049
2050 // Strip off any constant offsets so that we can reason about them.
2051 // It's tempting to use getUnderlyingObject or even just stripInBoundsOffsets
2052 // here and compare base addresses like AliasAnalysis does, however there are
2053 // numerous hazards. AliasAnalysis and its utilities rely on special rules
2054 // governing loads and stores which don't apply to icmps. Also, AliasAnalysis
2055 // doesn't need to guarantee pointer inequality when it says NoAlias.
2056 Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS);
2057 Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS);
2058
2059 // If LHS and RHS are related via constant offsets to the same base
2060 // value, we can replace it with an icmp which just compares the offsets.
2061 if (LHS == RHS)
2062 return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset);
2063
2064 // Various optimizations for (in)equality comparisons.
2065 if (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE) {
2066 // Different non-empty allocations that exist at the same time have
2067 // different addresses (if the program can tell). Global variables always
2068 // exist, so they always exist during the lifetime of each other and all
2069 // allocas. Two different allocas usually have different addresses...
2070 //
2071 // However, if there's an @llvm.stackrestore dynamically in between two
2072 // allocas, they may have the same address. It's tempting to reduce the
2073 // scope of the problem by only looking at *static* allocas here. That would
2074 // cover the majority of allocas while significantly reducing the likelihood
2075 // of having an @llvm.stackrestore pop up in the middle. However, it's not
2076 // actually impossible for an @llvm.stackrestore to pop up in the middle of
2077 // an entry block. Also, if we have a block that's not attached to a
2078 // function, we can't tell if it's "static" under the current definition.
2079 // Theoretically, this problem could be fixed by creating a new kind of
2080 // instruction kind specifically for static allocas. Such a new instruction
2081 // could be required to be at the top of the entry block, thus preventing it
2082 // from being subject to a @llvm.stackrestore. Instcombine could even
2083 // convert regular allocas into these special allocas. It'd be nifty.
2084 // However, until then, this problem remains open.
2085 //
2086 // So, we'll assume that two non-empty allocas have different addresses
2087 // for now.
2088 //
2089 // With all that, if the offsets are within the bounds of their allocations
2090 // (and not one-past-the-end! so we can't use inbounds!), and their
2091 // allocations aren't the same, the pointers are not equal.
2092 //
2093 // Note that it's not necessary to check for LHS being a global variable
2094 // address, due to canonicalization and constant folding.
2095 if (isa<AllocaInst>(LHS) &&
2096 (isa<AllocaInst>(RHS) || isa<GlobalVariable>(RHS))) {
2097 ConstantInt *LHSOffsetCI = dyn_cast<ConstantInt>(LHSOffset);
2098 ConstantInt *RHSOffsetCI = dyn_cast<ConstantInt>(RHSOffset);
2099 uint64_t LHSSize, RHSSize;
2100 if (LHSOffsetCI && RHSOffsetCI &&
2101 getObjectSize(LHS, LHSSize, DL, TLI) &&
2102 getObjectSize(RHS, RHSSize, DL, TLI)) {
2103 const APInt &LHSOffsetValue = LHSOffsetCI->getValue();
2104 const APInt &RHSOffsetValue = RHSOffsetCI->getValue();
2105 if (!LHSOffsetValue.isNegative() &&
2106 !RHSOffsetValue.isNegative() &&
2107 LHSOffsetValue.ult(LHSSize) &&
2108 RHSOffsetValue.ult(RHSSize)) {
2109 return ConstantInt::get(GetCompareTy(LHS),
2110 !CmpInst::isTrueWhenEqual(Pred));
2111 }
2112 }
2113
2114 // Repeat the above check but this time without depending on DataLayout
2115 // or being able to compute a precise size.
2116 if (!cast<PointerType>(LHS->getType())->isEmptyTy() &&
2117 !cast<PointerType>(RHS->getType())->isEmptyTy() &&
2118 LHSOffset->isNullValue() &&
2119 RHSOffset->isNullValue())
2120 return ConstantInt::get(GetCompareTy(LHS),
2121 !CmpInst::isTrueWhenEqual(Pred));
2122 }
2123
2124 // Even if an non-inbounds GEP occurs along the path we can still optimize
2125 // equality comparisons concerning the result. We avoid walking the whole
2126 // chain again by starting where the last calls to
2127 // stripAndComputeConstantOffsets left off and accumulate the offsets.
2128 Constant *LHSNoBound = stripAndComputeConstantOffsets(DL, LHS, true);
2129 Constant *RHSNoBound = stripAndComputeConstantOffsets(DL, RHS, true);
2130 if (LHS == RHS)
2131 return ConstantExpr::getICmp(Pred,
2132 ConstantExpr::getAdd(LHSOffset, LHSNoBound),
2133 ConstantExpr::getAdd(RHSOffset, RHSNoBound));
2134
2135 // If one side of the equality comparison must come from a noalias call
2136 // (meaning a system memory allocation function), and the other side must
2137 // come from a pointer that cannot overlap with dynamically-allocated
2138 // memory within the lifetime of the current function (allocas, byval
2139 // arguments, globals), then determine the comparison result here.
2140 SmallVector<Value *, 8> LHSUObjs, RHSUObjs;
2141 GetUnderlyingObjects(LHS, LHSUObjs, DL);
2142 GetUnderlyingObjects(RHS, RHSUObjs, DL);
2143
2144 // Is the set of underlying objects all noalias calls?
2145 auto IsNAC = [](ArrayRef<Value *> Objects) {
2146 return all_of(Objects, isNoAliasCall);
2147 };
2148
2149 // Is the set of underlying objects all things which must be disjoint from
2150 // noalias calls. For allocas, we consider only static ones (dynamic
2151 // allocas might be transformed into calls to malloc not simultaneously
2152 // live with the compared-to allocation). For globals, we exclude symbols
2153 // that might be resolve lazily to symbols in another dynamically-loaded
2154 // library (and, thus, could be malloc'ed by the implementation).
2155 auto IsAllocDisjoint = [](ArrayRef<Value *> Objects) {
2156 return all_of(Objects, [](Value *V) {
2157 if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
2158 return AI->getParent() && AI->getFunction() && AI->isStaticAlloca();
2159 if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
2160 return (GV->hasLocalLinkage() || GV->hasHiddenVisibility() ||
2161 GV->hasProtectedVisibility() || GV->hasGlobalUnnamedAddr()) &&
2162 !GV->isThreadLocal();
2163 if (const Argument *A = dyn_cast<Argument>(V))
2164 return A->hasByValAttr();
2165 return false;
2166 });
2167 };
2168
2169 if ((IsNAC(LHSUObjs) && IsAllocDisjoint(RHSUObjs)) ||
2170 (IsNAC(RHSUObjs) && IsAllocDisjoint(LHSUObjs)))
2171 return ConstantInt::get(GetCompareTy(LHS),
2172 !CmpInst::isTrueWhenEqual(Pred));
2173
2174 // Fold comparisons for non-escaping pointer even if the allocation call
2175 // cannot be elided. We cannot fold malloc comparison to null. Also, the
2176 // dynamic allocation call could be either of the operands.
2177 Value *MI = nullptr;
2178 if (isAllocLikeFn(LHS, TLI) &&
2179 llvm::isKnownNonZero(RHS, DL, 0, nullptr, CxtI, DT))
2180 MI = LHS;
2181 else if (isAllocLikeFn(RHS, TLI) &&
2182 llvm::isKnownNonZero(LHS, DL, 0, nullptr, CxtI, DT))
2183 MI = RHS;
2184 // FIXME: We should also fold the compare when the pointer escapes, but the
2185 // compare dominates the pointer escape
2186 if (MI && !PointerMayBeCaptured(MI, true, true))
2187 return ConstantInt::get(GetCompareTy(LHS),
2188 CmpInst::isFalseWhenEqual(Pred));
2189 }
2190
2191 // Otherwise, fail.
2192 return nullptr;
2193}
2194
2195/// Fold an icmp when its operands have i1 scalar type.
2196static Value *simplifyICmpOfBools(CmpInst::Predicate Pred, Value *LHS,
2197 Value *RHS, const SimplifyQuery &Q) {
2198 Type *ITy = GetCompareTy(LHS); // The return type.
2199 Type *OpTy = LHS->getType(); // The operand type.
2200 if (!OpTy->isIntOrIntVectorTy(1))
2201 return nullptr;
2202
2203 // A boolean compared to true/false can be simplified in 14 out of the 20
2204 // (10 predicates * 2 constants) possible combinations. Cases not handled here
2205 // require a 'not' of the LHS, so those must be transformed in InstCombine.
2206 if (match(RHS, m_Zero())) {
2207 switch (Pred) {
2208 case CmpInst::ICMP_NE: // X != 0 -> X
2209 case CmpInst::ICMP_UGT: // X >u 0 -> X
2210 case CmpInst::ICMP_SLT: // X <s 0 -> X
2211 return LHS;
2212
2213 case CmpInst::ICMP_ULT: // X <u 0 -> false
2214 case CmpInst::ICMP_SGT: // X >s 0 -> false
2215 return getFalse(ITy);
2216
2217 case CmpInst::ICMP_UGE: // X >=u 0 -> true
2218 case CmpInst::ICMP_SLE: // X <=s 0 -> true
2219 return getTrue(ITy);
2220
2221 default: break;
2222 }
2223 } else if (match(RHS, m_One())) {
2224 switch (Pred) {
2225 case CmpInst::ICMP_EQ: // X == 1 -> X
2226 case CmpInst::ICMP_UGE: // X >=u 1 -> X
2227 case CmpInst::ICMP_SLE: // X <=s -1 -> X
2228 return LHS;
2229
2230 case CmpInst::ICMP_UGT: // X >u 1 -> false
2231 case CmpInst::ICMP_SLT: // X <s -1 -> false
2232 return getFalse(ITy);
2233
2234 case CmpInst::ICMP_ULE: // X <=u 1 -> true
2235 case CmpInst::ICMP_SGE: // X >=s -1 -> true
2236 return getTrue(ITy);
2237
2238 default: break;
2239 }
2240 }
2241
2242 switch (Pred) {
2243 default:
2244 break;
2245 case ICmpInst::ICMP_UGE:
2246 if (isImpliedCondition(RHS, LHS, Q.DL).getValueOr(false))
2247 return getTrue(ITy);
2248 break;
2249 case ICmpInst::ICMP_SGE:
2250 /// For signed comparison, the values for an i1 are 0 and -1
2251 /// respectively. This maps into a truth table of:
2252 /// LHS | RHS | LHS >=s RHS | LHS implies RHS
2253 /// 0 | 0 | 1 (0 >= 0) | 1
2254 /// 0 | 1 | 1 (0 >= -1) | 1
2255 /// 1 | 0 | 0 (-1 >= 0) | 0
2256 /// 1 | 1 | 1 (-1 >= -1) | 1
2257 if (isImpliedCondition(LHS, RHS, Q.DL).getValueOr(false))
2258 return getTrue(ITy);
2259 break;
2260 case ICmpInst::ICMP_ULE:
2261 if (isImpliedCondition(LHS, RHS, Q.DL).getValueOr(false))
2262 return getTrue(ITy);
2263 break;
2264 }
2265
2266 return nullptr;
2267}
2268
2269/// Try hard to fold icmp with zero RHS because this is a common case.
2270static Value *simplifyICmpWithZero(CmpInst::Predicate Pred, Value *LHS,
2271 Value *RHS, const SimplifyQuery &Q) {
2272 if (!match(RHS, m_Zero()))
2273 return nullptr;
2274
2275 Type *ITy = GetCompareTy(LHS); // The return type.
2276 switch (Pred) {
2277 default:
2278 llvm_unreachable("Unknown ICmp predicate!")::llvm::llvm_unreachable_internal("Unknown ICmp predicate!", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 2278)
;
2279 case ICmpInst::ICMP_ULT:
2280 return getFalse(ITy);
2281 case ICmpInst::ICMP_UGE:
2282 return getTrue(ITy);
2283 case ICmpInst::ICMP_EQ:
2284 case ICmpInst::ICMP_ULE:
2285 if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2286 return getFalse(ITy);
2287 break;
2288 case ICmpInst::ICMP_NE:
2289 case ICmpInst::ICMP_UGT:
2290 if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2291 return getTrue(ITy);
2292 break;
2293 case ICmpInst::ICMP_SLT: {
2294 KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2295 if (LHSKnown.isNegative())
2296 return getTrue(ITy);
2297 if (LHSKnown.isNonNegative())
2298 return getFalse(ITy);
2299 break;
2300 }
2301 case ICmpInst::ICMP_SLE: {
2302 KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2303 if (LHSKnown.isNegative())
2304 return getTrue(ITy);
2305 if (LHSKnown.isNonNegative() &&
2306 isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2307 return getFalse(ITy);
2308 break;
2309 }
2310 case ICmpInst::ICMP_SGE: {
2311 KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2312 if (LHSKnown.isNegative())
2313 return getFalse(ITy);
2314 if (LHSKnown.isNonNegative())
2315 return getTrue(ITy);
2316 break;
2317 }
2318 case ICmpInst::ICMP_SGT: {
2319 KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2320 if (LHSKnown.isNegative())
2321 return getFalse(ITy);
2322 if (LHSKnown.isNonNegative() &&
2323 isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2324 return getTrue(ITy);
2325 break;
2326 }
2327 }
2328
2329 return nullptr;
2330}
2331
2332/// Many binary operators with a constant operand have an easy-to-compute
2333/// range of outputs. This can be used to fold a comparison to always true or
2334/// always false.
2335static void setLimitsForBinOp(BinaryOperator &BO, APInt &Lower, APInt &Upper) {
2336 unsigned Width = Lower.getBitWidth();
2337 const APInt *C;
2338 switch (BO.getOpcode()) {
2339 case Instruction::Add:
2340 if (match(BO.getOperand(1), m_APInt(C)) && !C->isNullValue()) {
2341 // FIXME: If we have both nuw and nsw, we should reduce the range further.
2342 if (BO.hasNoUnsignedWrap()) {
2343 // 'add nuw x, C' produces [C, UINT_MAX].
2344 Lower = *C;
2345 } else if (BO.hasNoSignedWrap()) {
2346 if (C->isNegative()) {
2347 // 'add nsw x, -C' produces [SINT_MIN, SINT_MAX - C].
2348 Lower = APInt::getSignedMinValue(Width);
2349 Upper = APInt::getSignedMaxValue(Width) + *C + 1;
2350 } else {
2351 // 'add nsw x, +C' produces [SINT_MIN + C, SINT_MAX].
2352 Lower = APInt::getSignedMinValue(Width) + *C;
2353 Upper = APInt::getSignedMaxValue(Width) + 1;
2354 }
2355 }
2356 }
2357 break;
2358
2359 case Instruction::And:
2360 if (match(BO.getOperand(1), m_APInt(C)))
2361 // 'and x, C' produces [0, C].
2362 Upper = *C + 1;
2363 break;
2364
2365 case Instruction::Or:
2366 if (match(BO.getOperand(1), m_APInt(C)))
2367 // 'or x, C' produces [C, UINT_MAX].
2368 Lower = *C;
2369 break;
2370
2371 case Instruction::AShr:
2372 if (match(BO.getOperand(1), m_APInt(C)) && C->ult(Width)) {
2373 // 'ashr x, C' produces [INT_MIN >> C, INT_MAX >> C].
2374 Lower = APInt::getSignedMinValue(Width).ashr(*C);
2375 Upper = APInt::getSignedMaxValue(Width).ashr(*C) + 1;
2376 } else if (match(BO.getOperand(0), m_APInt(C))) {
2377 unsigned ShiftAmount = Width - 1;
2378 if (!C->isNullValue() && BO.isExact())
2379 ShiftAmount = C->countTrailingZeros();
2380 if (C->isNegative()) {
2381 // 'ashr C, x' produces [C, C >> (Width-1)]
2382 Lower = *C;
2383 Upper = C->ashr(ShiftAmount) + 1;
2384 } else {
2385 // 'ashr C, x' produces [C >> (Width-1), C]
2386 Lower = C->ashr(ShiftAmount);
2387 Upper = *C + 1;
2388 }
2389 }
2390 break;
2391
2392 case Instruction::LShr:
2393 if (match(BO.getOperand(1), m_APInt(C)) && C->ult(Width)) {
2394 // 'lshr x, C' produces [0, UINT_MAX >> C].
2395 Upper = APInt::getAllOnesValue(Width).lshr(*C) + 1;
2396 } else if (match(BO.getOperand(0), m_APInt(C))) {
2397 // 'lshr C, x' produces [C >> (Width-1), C].
2398 unsigned ShiftAmount = Width - 1;
2399 if (!C->isNullValue() && BO.isExact())
2400 ShiftAmount = C->countTrailingZeros();
2401 Lower = C->lshr(ShiftAmount);
2402 Upper = *C + 1;
2403 }
2404 break;
2405
2406 case Instruction::Shl:
2407 if (match(BO.getOperand(0), m_APInt(C))) {
2408 if (BO.hasNoUnsignedWrap()) {
2409 // 'shl nuw C, x' produces [C, C << CLZ(C)]
2410 Lower = *C;
2411 Upper = Lower.shl(Lower.countLeadingZeros()) + 1;
2412 } else if (BO.hasNoSignedWrap()) { // TODO: What if both nuw+nsw?
2413 if (C->isNegative()) {
2414 // 'shl nsw C, x' produces [C << CLO(C)-1, C]
2415 unsigned ShiftAmount = C->countLeadingOnes() - 1;
2416 Lower = C->shl(ShiftAmount);
2417 Upper = *C + 1;
2418 } else {
2419 // 'shl nsw C, x' produces [C, C << CLZ(C)-1]
2420 unsigned ShiftAmount = C->countLeadingZeros() - 1;
2421 Lower = *C;
2422 Upper = C->shl(ShiftAmount) + 1;
2423 }
2424 }
2425 }
2426 break;
2427
2428 case Instruction::SDiv:
2429 if (match(BO.getOperand(1), m_APInt(C))) {
2430 APInt IntMin = APInt::getSignedMinValue(Width);
2431 APInt IntMax = APInt::getSignedMaxValue(Width);
2432 if (C->isAllOnesValue()) {
2433 // 'sdiv x, -1' produces [INT_MIN + 1, INT_MAX]
2434 // where C != -1 and C != 0 and C != 1
2435 Lower = IntMin + 1;
2436 Upper = IntMax + 1;
2437 } else if (C->countLeadingZeros() < Width - 1) {
2438 // 'sdiv x, C' produces [INT_MIN / C, INT_MAX / C]
2439 // where C != -1 and C != 0 and C != 1
2440 Lower = IntMin.sdiv(*C);
2441 Upper = IntMax.sdiv(*C);
2442 if (Lower.sgt(Upper))
2443 std::swap(Lower, Upper);
2444 Upper = Upper + 1;
2445 assert(Upper != Lower && "Upper part of range has wrapped!")(static_cast <bool> (Upper != Lower && "Upper part of range has wrapped!"
) ? void (0) : __assert_fail ("Upper != Lower && \"Upper part of range has wrapped!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 2445, __extension__ __PRETTY_FUNCTION__))
;
2446 }
2447 } else if (match(BO.getOperand(0), m_APInt(C))) {
2448 if (C->isMinSignedValue()) {
2449 // 'sdiv INT_MIN, x' produces [INT_MIN, INT_MIN / -2].
2450 Lower = *C;
2451 Upper = Lower.lshr(1) + 1;
2452 } else {
2453 // 'sdiv C, x' produces [-|C|, |C|].
2454 Upper = C->abs() + 1;
2455 Lower = (-Upper) + 1;
2456 }
2457 }
2458 break;
2459
2460 case Instruction::UDiv:
2461 if (match(BO.getOperand(1), m_APInt(C)) && !C->isNullValue()) {
2462 // 'udiv x, C' produces [0, UINT_MAX / C].
2463 Upper = APInt::getMaxValue(Width).udiv(*C) + 1;
2464 } else if (match(BO.getOperand(0), m_APInt(C))) {
2465 // 'udiv C, x' produces [0, C].
2466 Upper = *C + 1;
2467 }
2468 break;
2469
2470 case Instruction::SRem:
2471 if (match(BO.getOperand(1), m_APInt(C))) {
2472 // 'srem x, C' produces (-|C|, |C|).
2473 Upper = C->abs();
2474 Lower = (-Upper) + 1;
2475 }
2476 break;
2477
2478 case Instruction::URem:
2479 if (match(BO.getOperand(1), m_APInt(C)))
2480 // 'urem x, C' produces [0, C).
2481 Upper = *C;
2482 break;
2483
2484 default:
2485 break;
2486 }
2487}
2488
2489static Value *simplifyICmpWithConstant(CmpInst::Predicate Pred, Value *LHS,
2490 Value *RHS) {
2491 Type *ITy = GetCompareTy(RHS); // The return type.
2492
2493 Value *X;
2494 // Sign-bit checks can be optimized to true/false after unsigned
2495 // floating-point casts:
2496 // icmp slt (bitcast (uitofp X)), 0 --> false
2497 // icmp sgt (bitcast (uitofp X)), -1 --> true
2498 if (match(LHS, m_BitCast(m_UIToFP(m_Value(X))))) {
2499 if (Pred == ICmpInst::ICMP_SLT && match(RHS, m_Zero()))
2500 return ConstantInt::getFalse(ITy);
2501 if (Pred == ICmpInst::ICMP_SGT && match(RHS, m_AllOnes()))
2502 return ConstantInt::getTrue(ITy);
2503 }
2504
2505 const APInt *C;
2506 if (!match(RHS, m_APInt(C)))
2507 return nullptr;
2508
2509 // Rule out tautological comparisons (eg., ult 0 or uge 0).
2510 ConstantRange RHS_CR = ConstantRange::makeExactICmpRegion(Pred, *C);
2511 if (RHS_CR.isEmptySet())
2512 return ConstantInt::getFalse(ITy);
2513 if (RHS_CR.isFullSet())
2514 return ConstantInt::getTrue(ITy);
2515
2516 // Find the range of possible values for binary operators.
2517 unsigned Width = C->getBitWidth();
2518 APInt Lower = APInt(Width, 0);
2519 APInt Upper = APInt(Width, 0);
2520 if (auto *BO = dyn_cast<BinaryOperator>(LHS))
2521 setLimitsForBinOp(*BO, Lower, Upper);
2522
2523 ConstantRange LHS_CR =
2524 Lower != Upper ? ConstantRange(Lower, Upper) : ConstantRange(Width, true);
2525
2526 if (auto *I = dyn_cast<Instruction>(LHS))
2527 if (auto *Ranges = I->getMetadata(LLVMContext::MD_range))
2528 LHS_CR = LHS_CR.intersectWith(getConstantRangeFromMetadata(*Ranges));
2529
2530 if (!LHS_CR.isFullSet()) {
2531 if (RHS_CR.contains(LHS_CR))
2532 return ConstantInt::getTrue(ITy);
2533 if (RHS_CR.inverse().contains(LHS_CR))
2534 return ConstantInt::getFalse(ITy);
2535 }
2536
2537 return nullptr;
2538}
2539
2540/// TODO: A large part of this logic is duplicated in InstCombine's
2541/// foldICmpBinOp(). We should be able to share that and avoid the code
2542/// duplication.
2543static Value *simplifyICmpWithBinOp(CmpInst::Predicate Pred, Value *LHS,
2544 Value *RHS, const SimplifyQuery &Q,
2545 unsigned MaxRecurse) {
2546 Type *ITy = GetCompareTy(LHS); // The return type.
2547
2548 BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
2549 BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
2550 if (MaxRecurse && (LBO || RBO)) {
2551 // Analyze the case when either LHS or RHS is an add instruction.
2552 Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
2553 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
2554 bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
2555 if (LBO && LBO->getOpcode() == Instruction::Add) {
2556 A = LBO->getOperand(0);
2557 B = LBO->getOperand(1);
2558 NoLHSWrapProblem =
2559 ICmpInst::isEquality(Pred) ||
2560 (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) ||
2561 (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap());
2562 }
2563 if (RBO && RBO->getOpcode() == Instruction::Add) {
2564 C = RBO->getOperand(0);
2565 D = RBO->getOperand(1);
2566 NoRHSWrapProblem =
2567 ICmpInst::isEquality(Pred) ||
2568 (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) ||
2569 (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap());
2570 }
2571
2572 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
2573 if ((A == RHS || B == RHS) && NoLHSWrapProblem)
2574 if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
2575 Constant::getNullValue(RHS->getType()), Q,
2576 MaxRecurse - 1))
2577 return V;
2578
2579 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
2580 if ((C == LHS || D == LHS) && NoRHSWrapProblem)
2581 if (Value *V =
2582 SimplifyICmpInst(Pred, Constant::getNullValue(LHS->getType()),
2583 C == LHS ? D : C, Q, MaxRecurse - 1))
2584 return V;
2585
2586 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
2587 if (A && C && (A == C || A == D || B == C || B == D) && NoLHSWrapProblem &&
2588 NoRHSWrapProblem) {
2589 // Determine Y and Z in the form icmp (X+Y), (X+Z).
2590 Value *Y, *Z;
2591 if (A == C) {
2592 // C + B == C + D -> B == D
2593 Y = B;
2594 Z = D;
2595 } else if (A == D) {
2596 // D + B == C + D -> B == C
2597 Y = B;
2598 Z = C;
2599 } else if (B == C) {
2600 // A + C == C + D -> A == D
2601 Y = A;
2602 Z = D;
2603 } else {
2604 assert(B == D)(static_cast <bool> (B == D) ? void (0) : __assert_fail
("B == D", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 2604, __extension__ __PRETTY_FUNCTION__))
;
2605 // A + D == C + D -> A == C
2606 Y = A;
2607 Z = C;
2608 }
2609 if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse - 1))
2610 return V;
2611 }
2612 }
2613
2614 {
2615 Value *Y = nullptr;
2616 // icmp pred (or X, Y), X
2617 if (LBO && match(LBO, m_c_Or(m_Value(Y), m_Specific(RHS)))) {
2618 if (Pred == ICmpInst::ICMP_ULT)
2619 return getFalse(ITy);
2620 if (Pred == ICmpInst::ICMP_UGE)
2621 return getTrue(ITy);
2622
2623 if (Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SGE) {
2624 KnownBits RHSKnown = computeKnownBits(RHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2625 KnownBits YKnown = computeKnownBits(Y, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2626 if (RHSKnown.isNonNegative() && YKnown.isNegative())
2627 return Pred == ICmpInst::ICMP_SLT ? getTrue(ITy) : getFalse(ITy);
2628 if (RHSKnown.isNegative() || YKnown.isNonNegative())
2629 return Pred == ICmpInst::ICMP_SLT ? getFalse(ITy) : getTrue(ITy);
2630 }
2631 }
2632 // icmp pred X, (or X, Y)
2633 if (RBO && match(RBO, m_c_Or(m_Value(Y), m_Specific(LHS)))) {
2634 if (Pred == ICmpInst::ICMP_ULE)
2635 return getTrue(ITy);
2636 if (Pred == ICmpInst::ICMP_UGT)
2637 return getFalse(ITy);
2638
2639 if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLE) {
2640 KnownBits LHSKnown = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2641 KnownBits YKnown = computeKnownBits(Y, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2642 if (LHSKnown.isNonNegative() && YKnown.isNegative())
2643 return Pred == ICmpInst::ICMP_SGT ? getTrue(ITy) : getFalse(ITy);
2644 if (LHSKnown.isNegative() || YKnown.isNonNegative())
2645 return Pred == ICmpInst::ICMP_SGT ? getFalse(ITy) : getTrue(ITy);
2646 }
2647 }
2648 }
2649
2650 // icmp pred (and X, Y), X
2651 if (LBO && match(LBO, m_c_And(m_Value(), m_Specific(RHS)))) {
2652 if (Pred == ICmpInst::ICMP_UGT)
2653 return getFalse(ITy);
2654 if (Pred == ICmpInst::ICMP_ULE)
2655 return getTrue(ITy);
2656 }
2657 // icmp pred X, (and X, Y)
2658 if (RBO && match(RBO, m_c_And(m_Value(), m_Specific(LHS)))) {
2659 if (Pred == ICmpInst::ICMP_UGE)
2660 return getTrue(ITy);
2661 if (Pred == ICmpInst::ICMP_ULT)
2662 return getFalse(ITy);
2663 }
2664
2665 // 0 - (zext X) pred C
2666 if (!CmpInst::isUnsigned(Pred) && match(LHS, m_Neg(m_ZExt(m_Value())))) {
2667 if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS)) {
2668 if (RHSC->getValue().isStrictlyPositive()) {
2669 if (Pred == ICmpInst::ICMP_SLT)
2670 return ConstantInt::getTrue(RHSC->getContext());
2671 if (Pred == ICmpInst::ICMP_SGE)
2672 return ConstantInt::getFalse(RHSC->getContext());
2673 if (Pred == ICmpInst::ICMP_EQ)
2674 return ConstantInt::getFalse(RHSC->getContext());
2675 if (Pred == ICmpInst::ICMP_NE)
2676 return ConstantInt::getTrue(RHSC->getContext());
2677 }
2678 if (RHSC->getValue().isNonNegative()) {
2679 if (Pred == ICmpInst::ICMP_SLE)
2680 return ConstantInt::getTrue(RHSC->getContext());
2681 if (Pred == ICmpInst::ICMP_SGT)
2682 return ConstantInt::getFalse(RHSC->getContext());
2683 }
2684 }
2685 }
2686
2687 // icmp pred (urem X, Y), Y
2688 if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
2689 switch (Pred) {
2690 default:
2691 break;
2692 case ICmpInst::ICMP_SGT:
2693 case ICmpInst::ICMP_SGE: {
2694 KnownBits Known = computeKnownBits(RHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2695 if (!Known.isNonNegative())
2696 break;
2697 LLVM_FALLTHROUGH[[clang::fallthrough]];
2698 }
2699 case ICmpInst::ICMP_EQ:
2700 case ICmpInst::ICMP_UGT:
2701 case ICmpInst::ICMP_UGE:
2702 return getFalse(ITy);
2703 case ICmpInst::ICMP_SLT:
2704 case ICmpInst::ICMP_SLE: {
2705 KnownBits Known = computeKnownBits(RHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2706 if (!Known.isNonNegative())
2707 break;
2708 LLVM_FALLTHROUGH[[clang::fallthrough]];
2709 }
2710 case ICmpInst::ICMP_NE:
2711 case ICmpInst::ICMP_ULT:
2712 case ICmpInst::ICMP_ULE:
2713 return getTrue(ITy);
2714 }
2715 }
2716
2717 // icmp pred X, (urem Y, X)
2718 if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
2719 switch (Pred) {
2720 default:
2721 break;
2722 case ICmpInst::ICMP_SGT:
2723 case ICmpInst::ICMP_SGE: {
2724 KnownBits Known = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2725 if (!Known.isNonNegative())
2726 break;
2727 LLVM_FALLTHROUGH[[clang::fallthrough]];
2728 }
2729 case ICmpInst::ICMP_NE:
2730 case ICmpInst::ICMP_UGT:
2731 case ICmpInst::ICMP_UGE:
2732 return getTrue(ITy);
2733 case ICmpInst::ICMP_SLT:
2734 case ICmpInst::ICMP_SLE: {
2735 KnownBits Known = computeKnownBits(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
2736 if (!Known.isNonNegative())
2737 break;
2738 LLVM_FALLTHROUGH[[clang::fallthrough]];
2739 }
2740 case ICmpInst::ICMP_EQ:
2741 case ICmpInst::ICMP_ULT:
2742 case ICmpInst::ICMP_ULE:
2743 return getFalse(ITy);
2744 }
2745 }
2746
2747 // x >> y <=u x
2748 // x udiv y <=u x.
2749 if (LBO && (match(LBO, m_LShr(m_Specific(RHS), m_Value())) ||
2750 match(LBO, m_UDiv(m_Specific(RHS), m_Value())))) {
2751 // icmp pred (X op Y), X
2752 if (Pred == ICmpInst::ICMP_UGT)
2753 return getFalse(ITy);
2754 if (Pred == ICmpInst::ICMP_ULE)
2755 return getTrue(ITy);
2756 }
2757
2758 // x >=u x >> y
2759 // x >=u x udiv y.
2760 if (RBO && (match(RBO, m_LShr(m_Specific(LHS), m_Value())) ||
2761 match(RBO, m_UDiv(m_Specific(LHS), m_Value())))) {
2762 // icmp pred X, (X op Y)
2763 if (Pred == ICmpInst::ICMP_ULT)
2764 return getFalse(ITy);
2765 if (Pred == ICmpInst::ICMP_UGE)
2766 return getTrue(ITy);
2767 }
2768
2769 // handle:
2770 // CI2 << X == CI
2771 // CI2 << X != CI
2772 //
2773 // where CI2 is a power of 2 and CI isn't
2774 if (auto *CI = dyn_cast<ConstantInt>(RHS)) {
2775 const APInt *CI2Val, *CIVal = &CI->getValue();
2776 if (LBO && match(LBO, m_Shl(m_APInt(CI2Val), m_Value())) &&
2777 CI2Val->isPowerOf2()) {
2778 if (!CIVal->isPowerOf2()) {
2779 // CI2 << X can equal zero in some circumstances,
2780 // this simplification is unsafe if CI is zero.
2781 //
2782 // We know it is safe if:
2783 // - The shift is nsw, we can't shift out the one bit.
2784 // - The shift is nuw, we can't shift out the one bit.
2785 // - CI2 is one
2786 // - CI isn't zero
2787 if (LBO->hasNoSignedWrap() || LBO->hasNoUnsignedWrap() ||
2788 CI2Val->isOneValue() || !CI->isZero()) {
2789 if (Pred == ICmpInst::ICMP_EQ)
2790 return ConstantInt::getFalse(RHS->getContext());
2791 if (Pred == ICmpInst::ICMP_NE)
2792 return ConstantInt::getTrue(RHS->getContext());
2793 }
2794 }
2795 if (CIVal->isSignMask() && CI2Val->isOneValue()) {
2796 if (Pred == ICmpInst::ICMP_UGT)
2797 return ConstantInt::getFalse(RHS->getContext());
2798 if (Pred == ICmpInst::ICMP_ULE)
2799 return ConstantInt::getTrue(RHS->getContext());
2800 }
2801 }
2802 }
2803
2804 if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
2805 LBO->getOperand(1) == RBO->getOperand(1)) {
2806 switch (LBO->getOpcode()) {
2807 default:
2808 break;
2809 case Instruction::UDiv:
2810 case Instruction::LShr:
2811 if (ICmpInst::isSigned(Pred) || !LBO->isExact() || !RBO->isExact())
2812 break;
2813 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2814 RBO->getOperand(0), Q, MaxRecurse - 1))
2815 return V;
2816 break;
2817 case Instruction::SDiv:
2818 if (!ICmpInst::isEquality(Pred) || !LBO->isExact() || !RBO->isExact())
2819 break;
2820 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2821 RBO->getOperand(0), Q, MaxRecurse - 1))
2822 return V;
2823 break;
2824 case Instruction::AShr:
2825 if (!LBO->isExact() || !RBO->isExact())
2826 break;
2827 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2828 RBO->getOperand(0), Q, MaxRecurse - 1))
2829 return V;
2830 break;
2831 case Instruction::Shl: {
2832 bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
2833 bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
2834 if (!NUW && !NSW)
2835 break;
2836 if (!NSW && ICmpInst::isSigned(Pred))
2837 break;
2838 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2839 RBO->getOperand(0), Q, MaxRecurse - 1))
2840 return V;
2841 break;
2842 }
2843 }
2844 }
2845 return nullptr;
2846}
2847
2848/// Simplify integer comparisons where at least one operand of the compare
2849/// matches an integer min/max idiom.
2850static Value *simplifyICmpWithMinMax(CmpInst::Predicate Pred, Value *LHS,
2851 Value *RHS, const SimplifyQuery &Q,
2852 unsigned MaxRecurse) {
2853 Type *ITy = GetCompareTy(LHS); // The return type.
2854 Value *A, *B;
2855 CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
2856 CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
2857
2858 // Signed variants on "max(a,b)>=a -> true".
2859 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2860 if (A != RHS)
2861 std::swap(A, B); // smax(A, B) pred A.
2862 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2863 // We analyze this as smax(A, B) pred A.
2864 P = Pred;
2865 } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
2866 (A == LHS || B == LHS)) {
2867 if (A != LHS)
2868 std::swap(A, B); // A pred smax(A, B).
2869 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2870 // We analyze this as smax(A, B) swapped-pred A.
2871 P = CmpInst::getSwappedPredicate(Pred);
2872 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2873 (A == RHS || B == RHS)) {
2874 if (A != RHS)
2875 std::swap(A, B); // smin(A, B) pred A.
2876 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2877 // We analyze this as smax(-A, -B) swapped-pred -A.
2878 // Note that we do not need to actually form -A or -B thanks to EqP.
2879 P = CmpInst::getSwappedPredicate(Pred);
2880 } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
2881 (A == LHS || B == LHS)) {
2882 if (A != LHS)
2883 std::swap(A, B); // A pred smin(A, B).
2884 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2885 // We analyze this as smax(-A, -B) pred -A.
2886 // Note that we do not need to actually form -A or -B thanks to EqP.
2887 P = Pred;
2888 }
2889 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2890 // Cases correspond to "max(A, B) p A".
2891 switch (P) {
2892 default:
2893 break;
2894 case CmpInst::ICMP_EQ:
2895 case CmpInst::ICMP_SLE:
2896 // Equivalent to "A EqP B". This may be the same as the condition tested
2897 // in the max/min; if so, we can just return that.
2898 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2899 return V;
2900 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2901 return V;
2902 // Otherwise, see if "A EqP B" simplifies.
2903 if (MaxRecurse)
2904 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse - 1))
2905 return V;
2906 break;
2907 case CmpInst::ICMP_NE:
2908 case CmpInst::ICMP_SGT: {
2909 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2910 // Equivalent to "A InvEqP B". This may be the same as the condition
2911 // tested in the max/min; if so, we can just return that.
2912 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2913 return V;
2914 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2915 return V;
2916 // Otherwise, see if "A InvEqP B" simplifies.
2917 if (MaxRecurse)
2918 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse - 1))
2919 return V;
2920 break;
2921 }
2922 case CmpInst::ICMP_SGE:
2923 // Always true.
2924 return getTrue(ITy);
2925 case CmpInst::ICMP_SLT:
2926 // Always false.
2927 return getFalse(ITy);
2928 }
2929 }
2930
2931 // Unsigned variants on "max(a,b)>=a -> true".
2932 P = CmpInst::BAD_ICMP_PREDICATE;
2933 if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2934 if (A != RHS)
2935 std::swap(A, B); // umax(A, B) pred A.
2936 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2937 // We analyze this as umax(A, B) pred A.
2938 P = Pred;
2939 } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
2940 (A == LHS || B == LHS)) {
2941 if (A != LHS)
2942 std::swap(A, B); // A pred umax(A, B).
2943 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2944 // We analyze this as umax(A, B) swapped-pred A.
2945 P = CmpInst::getSwappedPredicate(Pred);
2946 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2947 (A == RHS || B == RHS)) {
2948 if (A != RHS)
2949 std::swap(A, B); // umin(A, B) pred A.
2950 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2951 // We analyze this as umax(-A, -B) swapped-pred -A.
2952 // Note that we do not need to actually form -A or -B thanks to EqP.
2953 P = CmpInst::getSwappedPredicate(Pred);
2954 } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
2955 (A == LHS || B == LHS)) {
2956 if (A != LHS)
2957 std::swap(A, B); // A pred umin(A, B).
2958 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2959 // We analyze this as umax(-A, -B) pred -A.
2960 // Note that we do not need to actually form -A or -B thanks to EqP.
2961 P = Pred;
2962 }
2963 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2964 // Cases correspond to "max(A, B) p A".
2965 switch (P) {
2966 default:
2967 break;
2968 case CmpInst::ICMP_EQ:
2969 case CmpInst::ICMP_ULE:
2970 // Equivalent to "A EqP B". This may be the same as the condition tested
2971 // in the max/min; if so, we can just return that.
2972 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2973 return V;
2974 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2975 return V;
2976 // Otherwise, see if "A EqP B" simplifies.
2977 if (MaxRecurse)
2978 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse - 1))
2979 return V;
2980 break;
2981 case CmpInst::ICMP_NE:
2982 case CmpInst::ICMP_UGT: {
2983 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2984 // Equivalent to "A InvEqP B". This may be the same as the condition
2985 // tested in the max/min; if so, we can just return that.
2986 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2987 return V;
2988 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2989 return V;
2990 // Otherwise, see if "A InvEqP B" simplifies.
2991 if (MaxRecurse)
2992 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse - 1))
2993 return V;
2994 break;
2995 }
2996 case CmpInst::ICMP_UGE:
2997 // Always true.
2998 return getTrue(ITy);
2999 case CmpInst::ICMP_ULT:
3000 // Always false.
3001 return getFalse(ITy);
3002 }
3003 }
3004
3005 // Variants on "max(x,y) >= min(x,z)".
3006 Value *C, *D;
3007 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
3008 match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
3009 (A == C || A == D || B == C || B == D)) {
3010 // max(x, ?) pred min(x, ?).
3011 if (Pred == CmpInst::ICMP_SGE)
3012 // Always true.
3013 return getTrue(ITy);
3014 if (Pred == CmpInst::ICMP_SLT)
3015 // Always false.
3016 return getFalse(ITy);
3017 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
3018 match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
3019 (A == C || A == D || B == C || B == D)) {
3020 // min(x, ?) pred max(x, ?).
3021 if (Pred == CmpInst::ICMP_SLE)
3022 // Always true.
3023 return getTrue(ITy);
3024 if (Pred == CmpInst::ICMP_SGT)
3025 // Always false.
3026 return getFalse(ITy);
3027 } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
3028 match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
3029 (A == C || A == D || B == C || B == D)) {
3030 // max(x, ?) pred min(x, ?).
3031 if (Pred == CmpInst::ICMP_UGE)
3032 // Always true.
3033 return getTrue(ITy);
3034 if (Pred == CmpInst::ICMP_ULT)
3035 // Always false.
3036 return getFalse(ITy);
3037 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
3038 match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
3039 (A == C || A == D || B == C || B == D)) {
3040 // min(x, ?) pred max(x, ?).
3041 if (Pred == CmpInst::ICMP_ULE)
3042 // Always true.
3043 return getTrue(ITy);
3044 if (Pred == CmpInst::ICMP_UGT)
3045 // Always false.
3046 return getFalse(ITy);
3047 }
3048
3049 return nullptr;
3050}
3051
3052/// Given operands for an ICmpInst, see if we can fold the result.
3053/// If not, this returns null.
3054static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3055 const SimplifyQuery &Q, unsigned MaxRecurse) {
3056 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
3057 assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!")(static_cast <bool> (CmpInst::isIntPredicate(Pred) &&
"Not an integer compare!") ? void (0) : __assert_fail ("CmpInst::isIntPredicate(Pred) && \"Not an integer compare!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3057, __extension__ __PRETTY_FUNCTION__))
;
3058
3059 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
3060 if (Constant *CRHS = dyn_cast<Constant>(RHS))
3061 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
3062
3063 // If we have a constant, make sure it is on the RHS.
3064 std::swap(LHS, RHS);
3065 Pred = CmpInst::getSwappedPredicate(Pred);
3066 }
3067
3068 Type *ITy = GetCompareTy(LHS); // The return type.
3069
3070 // icmp X, X -> true/false
3071 // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
3072 // because X could be 0.
3073 if (LHS == RHS || isa<UndefValue>(RHS))
3074 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
3075
3076 if (Value *V = simplifyICmpOfBools(Pred, LHS, RHS, Q))
3077 return V;
3078
3079 if (Value *V = simplifyICmpWithZero(Pred, LHS, RHS, Q))
3080 return V;
3081
3082 if (Value *V = simplifyICmpWithConstant(Pred, LHS, RHS))
3083 return V;
3084
3085 // If both operands have range metadata, use the metadata
3086 // to simplify the comparison.
3087 if (isa<Instruction>(RHS) && isa<Instruction>(LHS)) {
3088 auto RHS_Instr = cast<Instruction>(RHS);
3089 auto LHS_Instr = cast<Instruction>(LHS);
3090
3091 if (RHS_Instr->getMetadata(LLVMContext::MD_range) &&
3092 LHS_Instr->getMetadata(LLVMContext::MD_range)) {
3093 auto RHS_CR = getConstantRangeFromMetadata(
3094 *RHS_Instr->getMetadata(LLVMContext::MD_range));
3095 auto LHS_CR = getConstantRangeFromMetadata(
3096 *LHS_Instr->getMetadata(LLVMContext::MD_range));
3097
3098 auto Satisfied_CR = ConstantRange::makeSatisfyingICmpRegion(Pred, RHS_CR);
3099 if (Satisfied_CR.contains(LHS_CR))
3100 return ConstantInt::getTrue(RHS->getContext());
3101
3102 auto InversedSatisfied_CR = ConstantRange::makeSatisfyingICmpRegion(
3103 CmpInst::getInversePredicate(Pred), RHS_CR);
3104 if (InversedSatisfied_CR.contains(LHS_CR))
3105 return ConstantInt::getFalse(RHS->getContext());
3106 }
3107 }
3108
3109 // Compare of cast, for example (zext X) != 0 -> X != 0
3110 if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
3111 Instruction *LI = cast<CastInst>(LHS);
3112 Value *SrcOp = LI->getOperand(0);
3113 Type *SrcTy = SrcOp->getType();
3114 Type *DstTy = LI->getType();
3115
3116 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
3117 // if the integer type is the same size as the pointer type.
3118 if (MaxRecurse && isa<PtrToIntInst>(LI) &&
3119 Q.DL.getTypeSizeInBits(SrcTy) == DstTy->getPrimitiveSizeInBits()) {
3120 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
3121 // Transfer the cast to the constant.
3122 if (Value *V = SimplifyICmpInst(Pred, SrcOp,
3123 ConstantExpr::getIntToPtr(RHSC, SrcTy),
3124 Q, MaxRecurse-1))
3125 return V;
3126 } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
3127 if (RI->getOperand(0)->getType() == SrcTy)
3128 // Compare without the cast.
3129 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
3130 Q, MaxRecurse-1))
3131 return V;
3132 }
3133 }
3134
3135 if (isa<ZExtInst>(LHS)) {
3136 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
3137 // same type.
3138 if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) {
3139 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
3140 // Compare X and Y. Note that signed predicates become unsigned.
3141 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
3142 SrcOp, RI->getOperand(0), Q,
3143 MaxRecurse-1))
3144 return V;
3145 }
3146 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
3147 // too. If not, then try to deduce the result of the comparison.
3148 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
3149 // Compute the constant that would happen if we truncated to SrcTy then
3150 // reextended to DstTy.
3151 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
3152 Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy);
3153
3154 // If the re-extended constant didn't change then this is effectively
3155 // also a case of comparing two zero-extended values.
3156 if (RExt == CI && MaxRecurse)
3157 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
3158 SrcOp, Trunc, Q, MaxRecurse-1))
3159 return V;
3160
3161 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
3162 // there. Use this to work out the result of the comparison.
3163 if (RExt != CI) {
3164 switch (Pred) {
3165 default: llvm_unreachable("Unknown ICmp predicate!")::llvm::llvm_unreachable_internal("Unknown ICmp predicate!", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3165)
;
3166 // LHS <u RHS.
3167 case ICmpInst::ICMP_EQ:
3168 case ICmpInst::ICMP_UGT:
3169 case ICmpInst::ICMP_UGE:
3170 return ConstantInt::getFalse(CI->getContext());
3171
3172 case ICmpInst::ICMP_NE:
3173 case ICmpInst::ICMP_ULT:
3174 case ICmpInst::ICMP_ULE:
3175 return ConstantInt::getTrue(CI->getContext());
3176
3177 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
3178 // is non-negative then LHS <s RHS.
3179 case ICmpInst::ICMP_SGT:
3180 case ICmpInst::ICMP_SGE:
3181 return CI->getValue().isNegative() ?
3182 ConstantInt::getTrue(CI->getContext()) :
3183 ConstantInt::getFalse(CI->getContext());
3184
3185 case ICmpInst::ICMP_SLT:
3186 case ICmpInst::ICMP_SLE:
3187 return CI->getValue().isNegative() ?
3188 ConstantInt::getFalse(CI->getContext()) :
3189 ConstantInt::getTrue(CI->getContext());
3190 }
3191 }
3192 }
3193 }
3194
3195 if (isa<SExtInst>(LHS)) {
3196 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
3197 // same type.
3198 if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) {
3199 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
3200 // Compare X and Y. Note that the predicate does not change.
3201 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
3202 Q, MaxRecurse-1))
3203 return V;
3204 }
3205 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
3206 // too. If not, then try to deduce the result of the comparison.
3207 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
3208 // Compute the constant that would happen if we truncated to SrcTy then
3209 // reextended to DstTy.
3210 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
3211 Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy);
3212
3213 // If the re-extended constant didn't change then this is effectively
3214 // also a case of comparing two sign-extended values.
3215 if (RExt == CI && MaxRecurse)
3216 if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
3217 return V;
3218
3219 // Otherwise the upper bits of LHS are all equal, while RHS has varying
3220 // bits there. Use this to work out the result of the comparison.
3221 if (RExt != CI) {
3222 switch (Pred) {
3223 default: llvm_unreachable("Unknown ICmp predicate!")::llvm::llvm_unreachable_internal("Unknown ICmp predicate!", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3223)
;
3224 case ICmpInst::ICMP_EQ:
3225 return ConstantInt::getFalse(CI->getContext());
3226 case ICmpInst::ICMP_NE:
3227 return ConstantInt::getTrue(CI->getContext());
3228
3229 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
3230 // LHS >s RHS.
3231 case ICmpInst::ICMP_SGT:
3232 case ICmpInst::ICMP_SGE:
3233 return CI->getValue().isNegative() ?
3234 ConstantInt::getTrue(CI->getContext()) :
3235 ConstantInt::getFalse(CI->getContext());
3236 case ICmpInst::ICMP_SLT:
3237 case ICmpInst::ICMP_SLE:
3238 return CI->getValue().isNegative() ?
3239 ConstantInt::getFalse(CI->getContext()) :
3240 ConstantInt::getTrue(CI->getContext());
3241
3242 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
3243 // LHS >u RHS.
3244 case ICmpInst::ICMP_UGT:
3245 case ICmpInst::ICMP_UGE:
3246 // Comparison is true iff the LHS <s 0.
3247 if (MaxRecurse)
3248 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
3249 Constant::getNullValue(SrcTy),
3250 Q, MaxRecurse-1))
3251 return V;
3252 break;
3253 case ICmpInst::ICMP_ULT:
3254 case ICmpInst::ICMP_ULE:
3255 // Comparison is true iff the LHS >=s 0.
3256 if (MaxRecurse)
3257 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
3258 Constant::getNullValue(SrcTy),
3259 Q, MaxRecurse-1))
3260 return V;
3261 break;
3262 }
3263 }
3264 }
3265 }
3266 }
3267
3268 // icmp eq|ne X, Y -> false|true if X != Y
3269 if (ICmpInst::isEquality(Pred) &&
3270 isKnownNonEqual(LHS, RHS, Q.DL, Q.AC, Q.CxtI, Q.DT)) {
3271 return Pred == ICmpInst::ICMP_NE ? getTrue(ITy) : getFalse(ITy);
3272 }
3273
3274 if (Value *V = simplifyICmpWithBinOp(Pred, LHS, RHS, Q, MaxRecurse))
3275 return V;
3276
3277 if (Value *V = simplifyICmpWithMinMax(Pred, LHS, RHS, Q, MaxRecurse))
3278 return V;
3279
3280 // Simplify comparisons of related pointers using a powerful, recursive
3281 // GEP-walk when we have target data available..
3282 if (LHS->getType()->isPointerTy())
3283 if (auto *C = computePointerICmp(Q.DL, Q.TLI, Q.DT, Pred, Q.AC, Q.CxtI, LHS,
3284 RHS))
3285 return C;
3286 if (auto *CLHS = dyn_cast<PtrToIntOperator>(LHS))
3287 if (auto *CRHS = dyn_cast<PtrToIntOperator>(RHS))
3288 if (Q.DL.getTypeSizeInBits(CLHS->getPointerOperandType()) ==
3289 Q.DL.getTypeSizeInBits(CLHS->getType()) &&
3290 Q.DL.getTypeSizeInBits(CRHS->getPointerOperandType()) ==
3291 Q.DL.getTypeSizeInBits(CRHS->getType()))
3292 if (auto *C = computePointerICmp(Q.DL, Q.TLI, Q.DT, Pred, Q.AC, Q.CxtI,
3293 CLHS->getPointerOperand(),
3294 CRHS->getPointerOperand()))
3295 return C;
3296
3297 if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
3298 if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
3299 if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
3300 GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
3301 (ICmpInst::isEquality(Pred) ||
3302 (GLHS->isInBounds() && GRHS->isInBounds() &&
3303 Pred == ICmpInst::getSignedPredicate(Pred)))) {
3304 // The bases are equal and the indices are constant. Build a constant
3305 // expression GEP with the same indices and a null base pointer to see
3306 // what constant folding can make out of it.
3307 Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
3308 SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
3309 Constant *NewLHS = ConstantExpr::getGetElementPtr(
3310 GLHS->getSourceElementType(), Null, IndicesLHS);
3311
3312 SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
3313 Constant *NewRHS = ConstantExpr::getGetElementPtr(
3314 GLHS->getSourceElementType(), Null, IndicesRHS);
3315 return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
3316 }
3317 }
3318 }
3319
3320 // If the comparison is with the result of a select instruction, check whether
3321 // comparing with either branch of the select always yields the same value.
3322 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3323 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
3324 return V;
3325
3326 // If the comparison is with the result of a phi instruction, check whether
3327 // doing the compare with each incoming phi value yields a common result.
3328 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3329 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
3330 return V;
3331
3332 return nullptr;
3333}
3334
3335Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3336 const SimplifyQuery &Q) {
3337 return ::SimplifyICmpInst(Predicate, LHS, RHS, Q, RecursionLimit);
3338}
3339
3340/// Given operands for an FCmpInst, see if we can fold the result.
3341/// If not, this returns null.
3342static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3343 FastMathFlags FMF, const SimplifyQuery &Q,
3344 unsigned MaxRecurse) {
3345 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
3346 assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!")(static_cast <bool> (CmpInst::isFPPredicate(Pred) &&
"Not an FP compare!") ? void (0) : __assert_fail ("CmpInst::isFPPredicate(Pred) && \"Not an FP compare!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3346, __extension__ __PRETTY_FUNCTION__))
;
3347
3348 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
4
Taking false branch
3349 if (Constant *CRHS = dyn_cast<Constant>(RHS))
3350 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
3351
3352 // If we have a constant, make sure it is on the RHS.
3353 std::swap(LHS, RHS);
3354 Pred = CmpInst::getSwappedPredicate(Pred);
3355 }
3356
3357 // Fold trivial predicates.
3358 Type *RetTy = GetCompareTy(LHS);
3359 if (Pred == FCmpInst::FCMP_FALSE)
5
Assuming 'Pred' is not equal to FCMP_FALSE
6
Taking false branch
3360 return getFalse(RetTy);
3361 if (Pred == FCmpInst::FCMP_TRUE)
7
Assuming 'Pred' is not equal to FCMP_TRUE
8
Taking false branch
3362 return getTrue(RetTy);
3363
3364 // UNO/ORD predicates can be trivially folded if NaNs are ignored.
3365 if (FMF.noNaNs()) {
9
Taking false branch
3366 if (Pred == FCmpInst::FCMP_UNO)
3367 return getFalse(RetTy);
3368 if (Pred == FCmpInst::FCMP_ORD)
3369 return getTrue(RetTy);
3370 }
3371
3372 // NaN is unordered; NaN is not ordered.
3373 assert((FCmpInst::isOrdered(Pred) || FCmpInst::isUnordered(Pred)) &&(static_cast <bool> ((FCmpInst::isOrdered(Pred) || FCmpInst
::isUnordered(Pred)) && "Comparison must be either ordered or unordered"
) ? void (0) : __assert_fail ("(FCmpInst::isOrdered(Pred) || FCmpInst::isUnordered(Pred)) && \"Comparison must be either ordered or unordered\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3374, __extension__ __PRETTY_FUNCTION__))
3374 "Comparison must be either ordered or unordered")(static_cast <bool> ((FCmpInst::isOrdered(Pred) || FCmpInst
::isUnordered(Pred)) && "Comparison must be either ordered or unordered"
) ? void (0) : __assert_fail ("(FCmpInst::isOrdered(Pred) || FCmpInst::isUnordered(Pred)) && \"Comparison must be either ordered or unordered\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3374, __extension__ __PRETTY_FUNCTION__))
;
3375 if (match(RHS, m_NaN()))
10
Taking false branch
3376 return ConstantInt::get(RetTy, CmpInst::isUnordered(Pred));
3377
3378 // fcmp pred x, undef and fcmp pred undef, x
3379 // fold to true if unordered, false if ordered
3380 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS)) {
11
Taking false branch
3381 // Choosing NaN for the undef will always make unordered comparison succeed
3382 // and ordered comparison fail.
3383 return ConstantInt::get(RetTy, CmpInst::isUnordered(Pred));
3384 }
3385
3386 // fcmp x,x -> true/false. Not all compares are foldable.
3387 if (LHS == RHS) {
12
Assuming 'LHS' is not equal to 'RHS'
13
Taking false branch
3388 if (CmpInst::isTrueWhenEqual(Pred))
3389 return getTrue(RetTy);
3390 if (CmpInst::isFalseWhenEqual(Pred))
3391 return getFalse(RetTy);
3392 }
3393
3394 // Handle fcmp with constant RHS.
3395 const APFloat *C;
3396 if (match(RHS, m_APFloat(C))) {
14
Taking false branch
3397 // Check whether the constant is an infinity.
3398 if (C->isInfinity()) {
3399 if (C->isNegative()) {
3400 switch (Pred) {
3401 case FCmpInst::FCMP_OLT:
3402 // No value is ordered and less than negative infinity.
3403 return getFalse(RetTy);
3404 case FCmpInst::FCMP_UGE:
3405 // All values are unordered with or at least negative infinity.
3406 return getTrue(RetTy);
3407 default:
3408 break;
3409 }
3410 } else {
3411 switch (Pred) {
3412 case FCmpInst::FCMP_OGT:
3413 // No value is ordered and greater than infinity.
3414 return getFalse(RetTy);
3415 case FCmpInst::FCMP_ULE:
3416 // All values are unordered with and at most infinity.
3417 return getTrue(RetTy);
3418 default:
3419 break;
3420 }
3421 }
3422 }
3423 if (C->isZero()) {
3424 switch (Pred) {
3425 case FCmpInst::FCMP_UGE:
3426 if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
3427 return getTrue(RetTy);
3428 break;
3429 case FCmpInst::FCMP_OLT:
3430 // X < 0
3431 if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
3432 return getFalse(RetTy);
3433 break;
3434 default:
3435 break;
3436 }
3437 } else if (C->isNegative()) {
3438 assert(!C->isNaN() && "Unexpected NaN constant!")(static_cast <bool> (!C->isNaN() && "Unexpected NaN constant!"
) ? void (0) : __assert_fail ("!C->isNaN() && \"Unexpected NaN constant!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 3438, __extension__ __PRETTY_FUNCTION__))
;
3439 // TODO: We can catch more cases by using a range check rather than
3440 // relying on CannotBeOrderedLessThanZero.
3441 switch (Pred) {
3442 case FCmpInst::FCMP_UGE:
3443 case FCmpInst::FCMP_UGT:
3444 case FCmpInst::FCMP_UNE:
3445 // (X >= 0) implies (X > C) when (C < 0)
3446 if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
3447 return getTrue(RetTy);
3448 break;
3449 case FCmpInst::FCMP_OEQ:
3450 case FCmpInst::FCMP_OLE:
3451 case FCmpInst::FCMP_OLT:
3452 // (X >= 0) implies !(X < C) when (C < 0)
3453 if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
3454 return getFalse(RetTy);
3455 break;
3456 default:
3457 break;
3458 }
3459 }
3460 }
3461
3462 // If the comparison is with the result of a select instruction, check whether
3463 // comparing with either branch of the select always yields the same value.
3464 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
15
Taking true branch
3465 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
16
Calling 'ThreadCmpOverSelect'
3466 return V;
3467
3468 // If the comparison is with the result of a phi instruction, check whether
3469 // doing the compare with each incoming phi value yields a common result.
3470 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3471 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
3472 return V;
3473
3474 return nullptr;
3475}
3476
3477Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3478 FastMathFlags FMF, const SimplifyQuery &Q) {
3479 return ::SimplifyFCmpInst(Predicate, LHS, RHS, FMF, Q, RecursionLimit);
3480}
3481
3482/// See if V simplifies when its operand Op is replaced with RepOp.
3483static const Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
3484 const SimplifyQuery &Q,
3485 unsigned MaxRecurse) {
3486 // Trivial replacement.
3487 if (V == Op)
3488 return RepOp;
3489
3490 // We cannot replace a constant, and shouldn't even try.
3491 if (isa<Constant>(Op))
3492 return nullptr;
3493
3494 auto *I = dyn_cast<Instruction>(V);
3495 if (!I)
3496 return nullptr;
3497
3498 // If this is a binary operator, try to simplify it with the replaced op.
3499 if (auto *B = dyn_cast<BinaryOperator>(I)) {
3500 // Consider:
3501 // %cmp = icmp eq i32 %x, 2147483647
3502 // %add = add nsw i32 %x, 1
3503 // %sel = select i1 %cmp, i32 -2147483648, i32 %add
3504 //
3505 // We can't replace %sel with %add unless we strip away the flags.
3506 if (isa<OverflowingBinaryOperator>(B))
3507 if (B->hasNoSignedWrap() || B->hasNoUnsignedWrap())
3508 return nullptr;
3509 if (isa<PossiblyExactOperator>(B))
3510 if (B->isExact())
3511 return nullptr;
3512
3513 if (MaxRecurse) {
3514 if (B->getOperand(0) == Op)
3515 return SimplifyBinOp(B->getOpcode(), RepOp, B->getOperand(1), Q,
3516 MaxRecurse - 1);
3517 if (B->getOperand(1) == Op)
3518 return SimplifyBinOp(B->getOpcode(), B->getOperand(0), RepOp, Q,
3519 MaxRecurse - 1);
3520 }
3521 }
3522
3523 // Same for CmpInsts.
3524 if (CmpInst *C = dyn_cast<CmpInst>(I)) {
3525 if (MaxRecurse) {
3526 if (C->getOperand(0) == Op)
3527 return SimplifyCmpInst(C->getPredicate(), RepOp, C->getOperand(1), Q,
3528 MaxRecurse - 1);
3529 if (C->getOperand(1) == Op)
3530 return SimplifyCmpInst(C->getPredicate(), C->getOperand(0), RepOp, Q,
3531 MaxRecurse - 1);
3532 }
3533 }
3534
3535 // TODO: We could hand off more cases to instsimplify here.
3536
3537 // If all operands are constant after substituting Op for RepOp then we can
3538 // constant fold the instruction.
3539 if (Constant *CRepOp = dyn_cast<Constant>(RepOp)) {
3540 // Build a list of all constant operands.
3541 SmallVector<Constant *, 8> ConstOps;
3542 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
3543 if (I->getOperand(i) == Op)
3544 ConstOps.push_back(CRepOp);
3545 else if (Constant *COp = dyn_cast<Constant>(I->getOperand(i)))
3546 ConstOps.push_back(COp);
3547 else
3548 break;
3549 }
3550
3551 // All operands were constants, fold it.
3552 if (ConstOps.size() == I->getNumOperands()) {
3553 if (CmpInst *C = dyn_cast<CmpInst>(I))
3554 return ConstantFoldCompareInstOperands(C->getPredicate(), ConstOps[0],
3555 ConstOps[1], Q.DL, Q.TLI);
3556
3557 if (LoadInst *LI = dyn_cast<LoadInst>(I))
3558 if (!LI->isVolatile())
3559 return ConstantFoldLoadFromConstPtr(ConstOps[0], LI->getType(), Q.DL);
3560
3561 return ConstantFoldInstOperands(I, ConstOps, Q.DL, Q.TLI);
3562 }
3563 }
3564
3565 return nullptr;
3566}
3567
3568/// Try to simplify a select instruction when its condition operand is an
3569/// integer comparison where one operand of the compare is a constant.
3570static Value *simplifySelectBitTest(Value *TrueVal, Value *FalseVal, Value *X,
3571 const APInt *Y, bool TrueWhenUnset) {
3572 const APInt *C;
3573
3574 // (X & Y) == 0 ? X & ~Y : X --> X
3575 // (X & Y) != 0 ? X & ~Y : X --> X & ~Y
3576 if (FalseVal == X && match(TrueVal, m_And(m_Specific(X), m_APInt(C))) &&
3577 *Y == ~*C)
3578 return TrueWhenUnset ? FalseVal : TrueVal;
3579
3580 // (X & Y) == 0 ? X : X & ~Y --> X & ~Y
3581 // (X & Y) != 0 ? X : X & ~Y --> X
3582 if (TrueVal == X && match(FalseVal, m_And(m_Specific(X), m_APInt(C))) &&
3583 *Y == ~*C)
3584 return TrueWhenUnset ? FalseVal : TrueVal;
3585
3586 if (Y->isPowerOf2()) {
3587 // (X & Y) == 0 ? X | Y : X --> X | Y
3588 // (X & Y) != 0 ? X | Y : X --> X
3589 if (FalseVal == X && match(TrueVal, m_Or(m_Specific(X), m_APInt(C))) &&
3590 *Y == *C)
3591 return TrueWhenUnset ? TrueVal : FalseVal;
3592
3593 // (X & Y) == 0 ? X : X | Y --> X
3594 // (X & Y) != 0 ? X : X | Y --> X | Y
3595 if (TrueVal == X && match(FalseVal, m_Or(m_Specific(X), m_APInt(C))) &&
3596 *Y == *C)
3597 return TrueWhenUnset ? TrueVal : FalseVal;
3598 }
3599
3600 return nullptr;
3601}
3602
3603/// An alternative way to test if a bit is set or not uses sgt/slt instead of
3604/// eq/ne.
3605static Value *simplifySelectWithFakeICmpEq(Value *CmpLHS, Value *CmpRHS,
3606 ICmpInst::Predicate Pred,
3607 Value *TrueVal, Value *FalseVal) {
3608 Value *X;
3609 APInt Mask;
3610 if (!decomposeBitTestICmp(CmpLHS, CmpRHS, Pred, X, Mask))
3611 return nullptr;
3612
3613 return simplifySelectBitTest(TrueVal, FalseVal, X, &Mask,
3614 Pred == ICmpInst::ICMP_EQ);
3615}
3616
3617/// Try to simplify a select instruction when its condition operand is an
3618/// integer comparison.
3619static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
3620 Value *FalseVal, const SimplifyQuery &Q,
3621 unsigned MaxRecurse) {
3622 ICmpInst::Predicate Pred;
3623 Value *CmpLHS, *CmpRHS;
3624 if (!match(CondVal, m_ICmp(Pred, m_Value(CmpLHS), m_Value(CmpRHS))))
3625 return nullptr;
3626
3627 if (ICmpInst::isEquality(Pred) && match(CmpRHS, m_Zero())) {
3628 Value *X;
3629 const APInt *Y;
3630 if (match(CmpLHS, m_And(m_Value(X), m_APInt(Y))))
3631 if (Value *V = simplifySelectBitTest(TrueVal, FalseVal, X, Y,
3632 Pred == ICmpInst::ICMP_EQ))
3633 return V;
3634 }
3635
3636 // Check for other compares that behave like bit test.
3637 if (Value *V = simplifySelectWithFakeICmpEq(CmpLHS, CmpRHS, Pred,
3638 TrueVal, FalseVal))
3639 return V;
3640
3641 // If we have an equality comparison, then we know the value in one of the
3642 // arms of the select. See if substituting this value into the arm and
3643 // simplifying the result yields the same value as the other arm.
3644 if (Pred == ICmpInst::ICMP_EQ) {
3645 if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3646 TrueVal ||
3647 SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3648 TrueVal)
3649 return FalseVal;
3650 if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3651 FalseVal ||
3652 SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3653 FalseVal)
3654 return FalseVal;
3655 } else if (Pred == ICmpInst::ICMP_NE) {
3656 if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3657 FalseVal ||
3658 SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3659 FalseVal)
3660 return TrueVal;
3661 if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3662 TrueVal ||
3663 SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3664 TrueVal)
3665 return TrueVal;
3666 }
3667
3668 return nullptr;
3669}
3670
3671/// Given operands for a SelectInst, see if we can fold the result.
3672/// If not, this returns null.
3673static Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
3674 const SimplifyQuery &Q, unsigned MaxRecurse) {
3675 if (auto *CondC = dyn_cast<Constant>(Cond)) {
3676 if (auto *TrueC = dyn_cast<Constant>(TrueVal))
3677 if (auto *FalseC = dyn_cast<Constant>(FalseVal))
3678 return ConstantFoldSelectInstruction(CondC, TrueC, FalseC);
3679
3680 // select undef, X, Y -> X or Y
3681 if (isa<UndefValue>(CondC))
3682 return isa<Constant>(FalseVal) ? FalseVal : TrueVal;
3683
3684 // TODO: Vector constants with undef elements don't simplify.
3685
3686 // select true, X, Y -> X
3687 if (CondC->isAllOnesValue())
3688 return TrueVal;
3689 // select false, X, Y -> Y
3690 if (CondC->isNullValue())
3691 return FalseVal;
3692 }
3693
3694 // select ?, X, X -> X
3695 if (TrueVal == FalseVal)
3696 return TrueVal;
3697
3698 if (isa<UndefValue>(TrueVal)) // select ?, undef, X -> X
3699 return FalseVal;
3700 if (isa<UndefValue>(FalseVal)) // select ?, X, undef -> X
3701 return TrueVal;
3702
3703 if (Value *V =
3704 simplifySelectWithICmpCond(Cond, TrueVal, FalseVal, Q, MaxRecurse))
3705 return V;
3706
3707 return nullptr;
3708}
3709
3710Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
3711 const SimplifyQuery &Q) {
3712 return ::SimplifySelectInst(Cond, TrueVal, FalseVal, Q, RecursionLimit);
3713}
3714
3715/// Given operands for an GetElementPtrInst, see if we can fold the result.
3716/// If not, this returns null.
3717static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
3718 const SimplifyQuery &Q, unsigned) {
3719 // The type of the GEP pointer operand.
3720 unsigned AS =
3721 cast<PointerType>(Ops[0]->getType()->getScalarType())->getAddressSpace();
3722
3723 // getelementptr P -> P.
3724 if (Ops.size() == 1)
3725 return Ops[0];
3726
3727 // Compute the (pointer) type returned by the GEP instruction.
3728 Type *LastType = GetElementPtrInst::getIndexedType(SrcTy, Ops.slice(1));
3729 Type *GEPTy = PointerType::get(LastType, AS);
3730 if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
3731 GEPTy = VectorType::get(GEPTy, VT->getNumElements());
3732 else if (VectorType *VT = dyn_cast<VectorType>(Ops[1]->getType()))
3733 GEPTy = VectorType::get(GEPTy, VT->getNumElements());
3734
3735 if (isa<UndefValue>(Ops[0]))
3736 return UndefValue::get(GEPTy);
3737
3738 if (Ops.size() == 2) {
3739 // getelementptr P, 0 -> P.
3740 if (match(Ops[1], m_Zero()) && Ops[0]->getType() == GEPTy)
3741 return Ops[0];
3742
3743 Type *Ty = SrcTy;
3744 if (Ty->isSized()) {
3745 Value *P;
3746 uint64_t C;
3747 uint64_t TyAllocSize = Q.DL.getTypeAllocSize(Ty);
3748 // getelementptr P, N -> P if P points to a type of zero size.
3749 if (TyAllocSize == 0 && Ops[0]->getType() == GEPTy)
3750 return Ops[0];
3751
3752 // The following transforms are only safe if the ptrtoint cast
3753 // doesn't truncate the pointers.
3754 if (Ops[1]->getType()->getScalarSizeInBits() ==
3755 Q.DL.getIndexSizeInBits(AS)) {
3756 auto PtrToIntOrZero = [GEPTy](Value *P) -> Value * {
3757 if (match(P, m_Zero()))
3758 return Constant::getNullValue(GEPTy);
3759 Value *Temp;
3760 if (match(P, m_PtrToInt(m_Value(Temp))))
3761 if (Temp->getType() == GEPTy)
3762 return Temp;
3763 return nullptr;
3764 };
3765
3766 // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
3767 if (TyAllocSize == 1 &&
3768 match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
3769 if (Value *R = PtrToIntOrZero(P))
3770 return R;
3771
3772 // getelementptr V, (ashr (sub P, V), C) -> Q
3773 // if P points to a type of size 1 << C.
3774 if (match(Ops[1],
3775 m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
3776 m_ConstantInt(C))) &&
3777 TyAllocSize == 1ULL << C)
3778 if (Value *R = PtrToIntOrZero(P))
3779 return R;
3780
3781 // getelementptr V, (sdiv (sub P, V), C) -> Q
3782 // if P points to a type of size C.
3783 if (match(Ops[1],
3784 m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
3785 m_SpecificInt(TyAllocSize))))
3786 if (Value *R = PtrToIntOrZero(P))
3787 return R;
3788 }
3789 }
3790 }
3791
3792 if (Q.DL.getTypeAllocSize(LastType) == 1 &&
3793 all_of(Ops.slice(1).drop_back(1),
3794 [](Value *Idx) { return match(Idx, m_Zero()); })) {
3795 unsigned IdxWidth =
3796 Q.DL.getIndexSizeInBits(Ops[0]->getType()->getPointerAddressSpace());
3797 if (Q.DL.getTypeSizeInBits(Ops.back()->getType()) == IdxWidth) {
3798 APInt BasePtrOffset(IdxWidth, 0);
3799 Value *StrippedBasePtr =
3800 Ops[0]->stripAndAccumulateInBoundsConstantOffsets(Q.DL,
3801 BasePtrOffset);
3802
3803 // gep (gep V, C), (sub 0, V) -> C
3804 if (match(Ops.back(),
3805 m_Sub(m_Zero(), m_PtrToInt(m_Specific(StrippedBasePtr))))) {
3806 auto *CI = ConstantInt::get(GEPTy->getContext(), BasePtrOffset);
3807 return ConstantExpr::getIntToPtr(CI, GEPTy);
3808 }
3809 // gep (gep V, C), (xor V, -1) -> C-1
3810 if (match(Ops.back(),
3811 m_Xor(m_PtrToInt(m_Specific(StrippedBasePtr)), m_AllOnes()))) {
3812 auto *CI = ConstantInt::get(GEPTy->getContext(), BasePtrOffset - 1);
3813 return ConstantExpr::getIntToPtr(CI, GEPTy);
3814 }
3815 }
3816 }
3817
3818 // Check to see if this is constant foldable.
3819 if (!all_of(Ops, [](Value *V) { return isa<Constant>(V); }))
3820 return nullptr;
3821
3822 auto *CE = ConstantExpr::getGetElementPtr(SrcTy, cast<Constant>(Ops[0]),
3823 Ops.slice(1));
3824 if (auto *CEFolded = ConstantFoldConstant(CE, Q.DL))
3825 return CEFolded;
3826 return CE;
3827}
3828
3829Value *llvm::SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
3830 const SimplifyQuery &Q) {
3831 return ::SimplifyGEPInst(SrcTy, Ops, Q, RecursionLimit);
3832}
3833
3834/// Given operands for an InsertValueInst, see if we can fold the result.
3835/// If not, this returns null.
3836static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
3837 ArrayRef<unsigned> Idxs, const SimplifyQuery &Q,
3838 unsigned) {
3839 if (Constant *CAgg = dyn_cast<Constant>(Agg))
3840 if (Constant *CVal = dyn_cast<Constant>(Val))
3841 return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
3842
3843 // insertvalue x, undef, n -> x
3844 if (match(Val, m_Undef()))
3845 return Agg;
3846
3847 // insertvalue x, (extractvalue y, n), n
3848 if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
3849 if (EV->getAggregateOperand()->getType() == Agg->getType() &&
3850 EV->getIndices() == Idxs) {
3851 // insertvalue undef, (extractvalue y, n), n -> y
3852 if (match(Agg, m_Undef()))
3853 return EV->getAggregateOperand();
3854
3855 // insertvalue y, (extractvalue y, n), n -> y
3856 if (Agg == EV->getAggregateOperand())
3857 return Agg;
3858 }
3859
3860 return nullptr;
3861}
3862
3863Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val,
3864 ArrayRef<unsigned> Idxs,
3865 const SimplifyQuery &Q) {
3866 return ::SimplifyInsertValueInst(Agg, Val, Idxs, Q, RecursionLimit);
3867}
3868
3869Value *llvm::SimplifyInsertElementInst(Value *Vec, Value *Val, Value *Idx,
3870 const SimplifyQuery &Q) {
3871 // Try to constant fold.
3872 auto *VecC = dyn_cast<Constant>(Vec);
3873 auto *ValC = dyn_cast<Constant>(Val);
3874 auto *IdxC = dyn_cast<Constant>(Idx);
3875 if (VecC && ValC && IdxC)
3876 return ConstantFoldInsertElementInstruction(VecC, ValC, IdxC);
3877
3878 // Fold into undef if index is out of bounds.
3879 if (auto *CI = dyn_cast<ConstantInt>(Idx)) {
3880 uint64_t NumElements = cast<VectorType>(Vec->getType())->getNumElements();
3881 if (CI->uge(NumElements))
3882 return UndefValue::get(Vec->getType());
3883 }
3884
3885 // If index is undef, it might be out of bounds (see above case)
3886 if (isa<UndefValue>(Idx))
3887 return UndefValue::get(Vec->getType());
3888
3889 return nullptr;
3890}
3891
3892/// Given operands for an ExtractValueInst, see if we can fold the result.
3893/// If not, this returns null.
3894static Value *SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
3895 const SimplifyQuery &, unsigned) {
3896 if (auto *CAgg = dyn_cast<Constant>(Agg))
3897 return ConstantFoldExtractValueInstruction(CAgg, Idxs);
3898
3899 // extractvalue x, (insertvalue y, elt, n), n -> elt
3900 unsigned NumIdxs = Idxs.size();
3901 for (auto *IVI = dyn_cast<InsertValueInst>(Agg); IVI != nullptr;
3902 IVI = dyn_cast<InsertValueInst>(IVI->getAggregateOperand())) {
3903 ArrayRef<unsigned> InsertValueIdxs = IVI->getIndices();
3904 unsigned NumInsertValueIdxs = InsertValueIdxs.size();
3905 unsigned NumCommonIdxs = std::min(NumInsertValueIdxs, NumIdxs);
3906 if (InsertValueIdxs.slice(0, NumCommonIdxs) ==
3907 Idxs.slice(0, NumCommonIdxs)) {
3908 if (NumIdxs == NumInsertValueIdxs)
3909 return IVI->getInsertedValueOperand();
3910 break;
3911 }
3912 }
3913
3914 return nullptr;
3915}
3916
3917Value *llvm::SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
3918 const SimplifyQuery &Q) {
3919 return ::SimplifyExtractValueInst(Agg, Idxs, Q, RecursionLimit);
3920}
3921
3922/// Given operands for an ExtractElementInst, see if we can fold the result.
3923/// If not, this returns null.
3924static Value *SimplifyExtractElementInst(Value *Vec, Value *Idx, const SimplifyQuery &,
3925 unsigned) {
3926 if (auto *CVec = dyn_cast<Constant>(Vec)) {
3927 if (auto *CIdx = dyn_cast<Constant>(Idx))
3928 return ConstantFoldExtractElementInstruction(CVec, CIdx);
3929
3930 // The index is not relevant if our vector is a splat.
3931 if (auto *Splat = CVec->getSplatValue())
3932 return Splat;
3933
3934 if (isa<UndefValue>(Vec))
3935 return UndefValue::get(Vec->getType()->getVectorElementType());
3936 }
3937
3938 // If extracting a specified index from the vector, see if we can recursively
3939 // find a previously computed scalar that was inserted into the vector.
3940 if (auto *IdxC = dyn_cast<ConstantInt>(Idx)) {
3941 if (IdxC->getValue().uge(Vec->getType()->getVectorNumElements()))
3942 // definitely out of bounds, thus undefined result
3943 return UndefValue::get(Vec->getType()->getVectorElementType());
3944 if (Value *Elt = findScalarElement(Vec, IdxC->getZExtValue()))
3945 return Elt;
3946 }
3947
3948 // An undef extract index can be arbitrarily chosen to be an out-of-range
3949 // index value, which would result in the instruction being undef.
3950 if (isa<UndefValue>(Idx))
3951 return UndefValue::get(Vec->getType()->getVectorElementType());
3952
3953 return nullptr;
3954}
3955
3956Value *llvm::SimplifyExtractElementInst(Value *Vec, Value *Idx,
3957 const SimplifyQuery &Q) {
3958 return ::SimplifyExtractElementInst(Vec, Idx, Q, RecursionLimit);
3959}
3960
3961/// See if we can fold the given phi. If not, returns null.
3962static Value *SimplifyPHINode(PHINode *PN, const SimplifyQuery &Q) {
3963 // If all of the PHI's incoming values are the same then replace the PHI node
3964 // with the common value.
3965 Value *CommonValue = nullptr;
3966 bool HasUndefInput = false;
3967 for (Value *Incoming : PN->incoming_values()) {
3968 // If the incoming value is the phi node itself, it can safely be skipped.
3969 if (Incoming == PN) continue;
3970 if (isa<UndefValue>(Incoming)) {
3971 // Remember that we saw an undef value, but otherwise ignore them.
3972 HasUndefInput = true;
3973 continue;
3974 }
3975 if (CommonValue && Incoming != CommonValue)
3976 return nullptr; // Not the same, bail out.
3977 CommonValue = Incoming;
3978 }
3979
3980 // If CommonValue is null then all of the incoming values were either undef or
3981 // equal to the phi node itself.
3982 if (!CommonValue)
3983 return UndefValue::get(PN->getType());
3984
3985 // If we have a PHI node like phi(X, undef, X), where X is defined by some
3986 // instruction, we cannot return X as the result of the PHI node unless it
3987 // dominates the PHI block.
3988 if (HasUndefInput)
3989 return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : nullptr;
3990
3991 return CommonValue;
3992}
3993
3994static Value *SimplifyCastInst(unsigned CastOpc, Value *Op,
3995 Type *Ty, const SimplifyQuery &Q, unsigned MaxRecurse) {
3996 if (auto *C = dyn_cast<Constant>(Op))
3997 return ConstantFoldCastOperand(CastOpc, C, Ty, Q.DL);
3998
3999 if (auto *CI = dyn_cast<CastInst>(Op)) {
4000 auto *Src = CI->getOperand(0);
4001 Type *SrcTy = Src->getType();
4002 Type *MidTy = CI->getType();
4003 Type *DstTy = Ty;
4004 if (Src->getType() == Ty) {
4005 auto FirstOp = static_cast<Instruction::CastOps>(CI->getOpcode());
4006 auto SecondOp = static_cast<Instruction::CastOps>(CastOpc);
4007 Type *SrcIntPtrTy =
4008 SrcTy->isPtrOrPtrVectorTy() ? Q.DL.getIntPtrType(SrcTy) : nullptr;
4009 Type *MidIntPtrTy =
4010 MidTy->isPtrOrPtrVectorTy() ? Q.DL.getIntPtrType(MidTy) : nullptr;
4011 Type *DstIntPtrTy =
4012 DstTy->isPtrOrPtrVectorTy() ? Q.DL.getIntPtrType(DstTy) : nullptr;
4013 if (CastInst::isEliminableCastPair(FirstOp, SecondOp, SrcTy, MidTy, DstTy,
4014 SrcIntPtrTy, MidIntPtrTy,
4015 DstIntPtrTy) == Instruction::BitCast)
4016 return Src;
4017 }
4018 }
4019
4020 // bitcast x -> x
4021 if (CastOpc == Instruction::BitCast)
4022 if (Op->getType() == Ty)
4023 return Op;
4024
4025 return nullptr;
4026}
4027
4028Value *llvm::SimplifyCastInst(unsigned CastOpc, Value *Op, Type *Ty,
4029 const SimplifyQuery &Q) {
4030 return ::SimplifyCastInst(CastOpc, Op, Ty, Q, RecursionLimit);
4031}
4032
4033/// For the given destination element of a shuffle, peek through shuffles to
4034/// match a root vector source operand that contains that element in the same
4035/// vector lane (ie, the same mask index), so we can eliminate the shuffle(s).
4036static Value *foldIdentityShuffles(int DestElt, Value *Op0, Value *Op1,
4037 int MaskVal, Value *RootVec,
4038 unsigned MaxRecurse) {
4039 if (!MaxRecurse--)
4040 return nullptr;
4041
4042 // Bail out if any mask value is undefined. That kind of shuffle may be
4043 // simplified further based on demanded bits or other folds.
4044 if (MaskVal == -1)
4045 return nullptr;
4046
4047 // The mask value chooses which source operand we need to look at next.
4048 int InVecNumElts = Op0->getType()->getVectorNumElements();
4049 int RootElt = MaskVal;
4050 Value *SourceOp = Op0;
4051 if (MaskVal >= InVecNumElts) {
4052 RootElt = MaskVal - InVecNumElts;
4053 SourceOp = Op1;
4054 }
4055
4056 // If the source operand is a shuffle itself, look through it to find the
4057 // matching root vector.
4058 if (auto *SourceShuf = dyn_cast<ShuffleVectorInst>(SourceOp)) {
4059 return foldIdentityShuffles(
4060 DestElt, SourceShuf->getOperand(0), SourceShuf->getOperand(1),
4061 SourceShuf->getMaskValue(RootElt), RootVec, MaxRecurse);
4062 }
4063
4064 // TODO: Look through bitcasts? What if the bitcast changes the vector element
4065 // size?
4066
4067 // The source operand is not a shuffle. Initialize the root vector value for
4068 // this shuffle if that has not been done yet.
4069 if (!RootVec)
4070 RootVec = SourceOp;
4071
4072 // Give up as soon as a source operand does not match the existing root value.
4073 if (RootVec != SourceOp)
4074 return nullptr;
4075
4076 // The element must be coming from the same lane in the source vector
4077 // (although it may have crossed lanes in intermediate shuffles).
4078 if (RootElt != DestElt)
4079 return nullptr;
4080
4081 return RootVec;
4082}
4083
4084static Value *SimplifyShuffleVectorInst(Value *Op0, Value *Op1, Constant *Mask,
4085 Type *RetTy, const SimplifyQuery &Q,
4086 unsigned MaxRecurse) {
4087 if (isa<UndefValue>(Mask))
4088 return UndefValue::get(RetTy);
4089
4090 Type *InVecTy = Op0->getType();
4091 unsigned MaskNumElts = Mask->getType()->getVectorNumElements();
4092 unsigned InVecNumElts = InVecTy->getVectorNumElements();
4093
4094 SmallVector<int, 32> Indices;
4095 ShuffleVectorInst::getShuffleMask(Mask, Indices);
4096 assert(MaskNumElts == Indices.size() &&(static_cast <bool> (MaskNumElts == Indices.size() &&
"Size of Indices not same as number of mask elements?") ? void
(0) : __assert_fail ("MaskNumElts == Indices.size() && \"Size of Indices not same as number of mask elements?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 4097, __extension__ __PRETTY_FUNCTION__))
4097 "Size of Indices not same as number of mask elements?")(static_cast <bool> (MaskNumElts == Indices.size() &&
"Size of Indices not same as number of mask elements?") ? void
(0) : __assert_fail ("MaskNumElts == Indices.size() && \"Size of Indices not same as number of mask elements?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 4097, __extension__ __PRETTY_FUNCTION__))
;
4098
4099 // Canonicalization: If mask does not select elements from an input vector,
4100 // replace that input vector with undef.
4101 bool MaskSelects0 = false, MaskSelects1 = false;
4102 for (unsigned i = 0; i != MaskNumElts; ++i) {
4103 if (Indices[i] == -1)
4104 continue;
4105 if ((unsigned)Indices[i] < InVecNumElts)
4106 MaskSelects0 = true;
4107 else
4108 MaskSelects1 = true;
4109 }
4110 if (!MaskSelects0)
4111 Op0 = UndefValue::get(InVecTy);
4112 if (!MaskSelects1)
4113 Op1 = UndefValue::get(InVecTy);
4114
4115 auto *Op0Const = dyn_cast<Constant>(Op0);
4116 auto *Op1Const = dyn_cast<Constant>(Op1);
4117
4118 // If all operands are constant, constant fold the shuffle.
4119 if (Op0Const && Op1Const)
4120 return ConstantFoldShuffleVectorInstruction(Op0Const, Op1Const, Mask);
4121
4122 // Canonicalization: if only one input vector is constant, it shall be the
4123 // second one.
4124 if (Op0Const && !Op1Const) {
4125 std::swap(Op0, Op1);
4126 ShuffleVectorInst::commuteShuffleMask(Indices, InVecNumElts);
4127 }
4128
4129 // A shuffle of a splat is always the splat itself. Legal if the shuffle's
4130 // value type is same as the input vectors' type.
4131 if (auto *OpShuf = dyn_cast<ShuffleVectorInst>(Op0))
4132 if (isa<UndefValue>(Op1) && RetTy == InVecTy &&
4133 OpShuf->getMask()->getSplatValue())
4134 return Op0;
4135
4136 // Don't fold a shuffle with undef mask elements. This may get folded in a
4137 // better way using demanded bits or other analysis.
4138 // TODO: Should we allow this?
4139 if (find(Indices, -1) != Indices.end())
4140 return nullptr;
4141
4142 // Check if every element of this shuffle can be mapped back to the
4143 // corresponding element of a single root vector. If so, we don't need this
4144 // shuffle. This handles simple identity shuffles as well as chains of
4145 // shuffles that may widen/narrow and/or move elements across lanes and back.
4146 Value *RootVec = nullptr;
4147 for (unsigned i = 0; i != MaskNumElts; ++i) {
4148 // Note that recursion is limited for each vector element, so if any element
4149 // exceeds the limit, this will fail to simplify.
4150 RootVec =
4151 foldIdentityShuffles(i, Op0, Op1, Indices[i], RootVec, MaxRecurse);
4152
4153 // We can't replace a widening/narrowing shuffle with one of its operands.
4154 if (!RootVec || RootVec->getType() != RetTy)
4155 return nullptr;
4156 }
4157 return RootVec;
4158}
4159
4160/// Given operands for a ShuffleVectorInst, fold the result or return null.
4161Value *llvm::SimplifyShuffleVectorInst(Value *Op0, Value *Op1, Constant *Mask,
4162 Type *RetTy, const SimplifyQuery &Q) {
4163 return ::SimplifyShuffleVectorInst(Op0, Op1, Mask, RetTy, Q, RecursionLimit);
4164}
4165
4166static Constant *propagateNaN(Constant *In) {
4167 // If the input is a vector with undef elements, just return a default NaN.
4168 if (!In->isNaN())
4169 return ConstantFP::getNaN(In->getType());
4170
4171 // Propagate the existing NaN constant when possible.
4172 // TODO: Should we quiet a signaling NaN?
4173 return In;
4174}
4175
4176static Constant *simplifyFPBinop(Value *Op0, Value *Op1) {
4177 if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1))
4178 return ConstantFP::getNaN(Op0->getType());
4179
4180 if (match(Op0, m_NaN()))
4181 return propagateNaN(cast<Constant>(Op0));
4182 if (match(Op1, m_NaN()))
4183 return propagateNaN(cast<Constant>(Op1));
4184
4185 return nullptr;
4186}
4187
4188/// Given operands for an FAdd, see if we can fold the result. If not, this
4189/// returns null.
4190static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4191 const SimplifyQuery &Q, unsigned MaxRecurse) {
4192 if (Constant *C = foldOrCommuteConstant(Instruction::FAdd, Op0, Op1, Q))
4193 return C;
4194
4195 if (Constant *C = simplifyFPBinop(Op0, Op1))
4196 return C;
4197
4198 // fadd X, -0 ==> X
4199 if (match(Op1, m_NegZeroFP()))
4200 return Op0;
4201
4202 // fadd X, 0 ==> X, when we know X is not -0
4203 if (match(Op1, m_PosZeroFP()) &&
4204 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0, Q.TLI)))
4205 return Op0;
4206
4207 // With nnan: (+/-0.0 - X) + X --> 0.0 (and commuted variant)
4208 // We don't have to explicitly exclude infinities (ninf): INF + -INF == NaN.
4209 // Negative zeros are allowed because we always end up with positive zero:
4210 // X = -0.0: (-0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
4211 // X = -0.0: ( 0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
4212 // X = 0.0: (-0.0 - ( 0.0)) + ( 0.0) == (-0.0) + ( 0.0) == 0.0
4213 // X = 0.0: ( 0.0 - ( 0.0)) + ( 0.0) == ( 0.0) + ( 0.0) == 0.0
4214 if (FMF.noNaNs() && (match(Op0, m_FSub(m_AnyZeroFP(), m_Specific(Op1))) ||
4215 match(Op1, m_FSub(m_AnyZeroFP(), m_Specific(Op0)))))
4216 return ConstantFP::getNullValue(Op0->getType());
4217
4218 return nullptr;
4219}
4220
4221/// Given operands for an FSub, see if we can fold the result. If not, this
4222/// returns null.
4223static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4224 const SimplifyQuery &Q, unsigned MaxRecurse) {
4225 if (Constant *C = foldOrCommuteConstant(Instruction::FSub, Op0, Op1, Q))
4226 return C;
4227
4228 if (Constant *C = simplifyFPBinop(Op0, Op1))
4229 return C;
4230
4231 // fsub X, +0 ==> X
4232 if (match(Op1, m_PosZeroFP()))
4233 return Op0;
4234
4235 // fsub X, -0 ==> X, when we know X is not -0
4236 if (match(Op1, m_NegZeroFP()) &&
4237 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0, Q.TLI)))
4238 return Op0;
4239
4240 // fsub -0.0, (fsub -0.0, X) ==> X
4241 Value *X;
4242 if (match(Op0, m_NegZeroFP()) &&
4243 match(Op1, m_FSub(m_NegZeroFP(), m_Value(X))))
4244 return X;
4245
4246 // fsub 0.0, (fsub 0.0, X) ==> X if signed zeros are ignored.
4247 if (FMF.noSignedZeros() && match(Op0, m_AnyZeroFP()) &&
4248 match(Op1, m_FSub(m_AnyZeroFP(), m_Value(X))))
4249 return X;
4250
4251 // fsub nnan x, x ==> 0.0
4252 if (FMF.noNaNs() && Op0 == Op1)
4253 return Constant::getNullValue(Op0->getType());
4254
4255 return nullptr;
4256}
4257
4258/// Given the operands for an FMul, see if we can fold the result
4259static Value *SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4260 const SimplifyQuery &Q, unsigned MaxRecurse) {
4261 if (Constant *C = foldOrCommuteConstant(Instruction::FMul, Op0, Op1, Q))
4262 return C;
4263
4264 if (Constant *C = simplifyFPBinop(Op0, Op1))
4265 return C;
4266
4267 // fmul X, 1.0 ==> X
4268 if (match(Op1, m_FPOne()))
4269 return Op0;
4270
4271 // fmul nnan nsz X, 0 ==> 0
4272 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZeroFP()))
4273 return ConstantFP::getNullValue(Op0->getType());
4274
4275 // sqrt(X) * sqrt(X) --> X, if we can:
4276 // 1. Remove the intermediate rounding (reassociate).
4277 // 2. Ignore non-zero negative numbers because sqrt would produce NAN.
4278 // 3. Ignore -0.0 because sqrt(-0.0) == -0.0, but -0.0 * -0.0 == 0.0.
4279 Value *X;
4280 if (Op0 == Op1 && match(Op0, m_Intrinsic<Intrinsic::sqrt>(m_Value(X))) &&
4281 FMF.allowReassoc() && FMF.noNaNs() && FMF.noSignedZeros())
4282 return X;
4283
4284 return nullptr;
4285}
4286
4287Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4288 const SimplifyQuery &Q) {
4289 return ::SimplifyFAddInst(Op0, Op1, FMF, Q, RecursionLimit);
4290}
4291
4292
4293Value *llvm::SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4294 const SimplifyQuery &Q) {
4295 return ::SimplifyFSubInst(Op0, Op1, FMF, Q, RecursionLimit);
4296}
4297
4298Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4299 const SimplifyQuery &Q) {
4300 return ::SimplifyFMulInst(Op0, Op1, FMF, Q, RecursionLimit);
4301}
4302
4303static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4304 const SimplifyQuery &Q, unsigned) {
4305 if (Constant *C = foldOrCommuteConstant(Instruction::FDiv, Op0, Op1, Q))
4306 return C;
4307
4308 if (Constant *C = simplifyFPBinop(Op0, Op1))
4309 return C;
4310
4311 // X / 1.0 -> X
4312 if (match(Op1, m_FPOne()))
4313 return Op0;
4314
4315 // 0 / X -> 0
4316 // Requires that NaNs are off (X could be zero) and signed zeroes are
4317 // ignored (X could be positive or negative, so the output sign is unknown).
4318 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZeroFP()))
4319 return ConstantFP::getNullValue(Op0->getType());
4320
4321 if (FMF.noNaNs()) {
4322 // X / X -> 1.0 is legal when NaNs are ignored.
4323 // We can ignore infinities because INF/INF is NaN.
4324 if (Op0 == Op1)
4325 return ConstantFP::get(Op0->getType(), 1.0);
4326
4327 // (X * Y) / Y --> X if we can reassociate to the above form.
4328 Value *X;
4329 if (FMF.allowReassoc() && match(Op0, m_c_FMul(m_Value(X), m_Specific(Op1))))
4330 return X;
4331
4332 // -X / X -> -1.0 and
4333 // X / -X -> -1.0 are legal when NaNs are ignored.
4334 // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored.
4335 if ((BinaryOperator::isFNeg(Op0, /*IgnoreZeroSign=*/true) &&
4336 BinaryOperator::getFNegArgument(Op0) == Op1) ||
4337 (BinaryOperator::isFNeg(Op1, /*IgnoreZeroSign=*/true) &&
4338 BinaryOperator::getFNegArgument(Op1) == Op0))
4339 return ConstantFP::get(Op0->getType(), -1.0);
4340 }
4341
4342 return nullptr;
4343}
4344
4345Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4346 const SimplifyQuery &Q) {
4347 return ::SimplifyFDivInst(Op0, Op1, FMF, Q, RecursionLimit);
4348}
4349
4350static Value *SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4351 const SimplifyQuery &Q, unsigned) {
4352 if (Constant *C = foldOrCommuteConstant(Instruction::FRem, Op0, Op1, Q))
4353 return C;
4354
4355 if (Constant *C = simplifyFPBinop(Op0, Op1))
4356 return C;
4357
4358 // Unlike fdiv, the result of frem always matches the sign of the dividend.
4359 // The constant match may include undef elements in a vector, so return a full
4360 // zero constant as the result.
4361 if (FMF.noNaNs()) {
4362 // +0 % X -> 0
4363 if (match(Op0, m_PosZeroFP()))
4364 return ConstantFP::getNullValue(Op0->getType());
4365 // -0 % X -> -0
4366 if (match(Op0, m_NegZeroFP()))
4367 return ConstantFP::getNegativeZero(Op0->getType());
4368 }
4369
4370 return nullptr;
4371}
4372
4373Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF,
4374 const SimplifyQuery &Q) {
4375 return ::SimplifyFRemInst(Op0, Op1, FMF, Q, RecursionLimit);
4376}
4377
4378//=== Helper functions for higher up the class hierarchy.
4379
4380/// Given operands for a BinaryOperator, see if we can fold the result.
4381/// If not, this returns null.
4382static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
4383 const SimplifyQuery &Q, unsigned MaxRecurse) {
4384 switch (Opcode) {
4385 case Instruction::Add:
4386 return SimplifyAddInst(LHS, RHS, false, false, Q, MaxRecurse);
4387 case Instruction::Sub:
4388 return SimplifySubInst(LHS, RHS, false, false, Q, MaxRecurse);
4389 case Instruction::Mul:
4390 return SimplifyMulInst(LHS, RHS, Q, MaxRecurse);
4391 case Instruction::SDiv:
4392 return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
4393 case Instruction::UDiv:
4394 return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
4395 case Instruction::SRem:
4396 return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
4397 case Instruction::URem:
4398 return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
4399 case Instruction::Shl:
4400 return SimplifyShlInst(LHS, RHS, false, false, Q, MaxRecurse);
4401 case Instruction::LShr:
4402 return SimplifyLShrInst(LHS, RHS, false, Q, MaxRecurse);
4403 case Instruction::AShr:
4404 return SimplifyAShrInst(LHS, RHS, false, Q, MaxRecurse);
4405 case Instruction::And:
4406 return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
4407 case Instruction::Or:
4408 return SimplifyOrInst(LHS, RHS, Q, MaxRecurse);
4409 case Instruction::Xor:
4410 return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
4411 case Instruction::FAdd:
4412 return SimplifyFAddInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
4413 case Instruction::FSub:
4414 return SimplifyFSubInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
4415 case Instruction::FMul:
4416 return SimplifyFMulInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
4417 case Instruction::FDiv:
4418 return SimplifyFDivInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
4419 case Instruction::FRem:
4420 return SimplifyFRemInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
4421 default:
4422 llvm_unreachable("Unexpected opcode")::llvm::llvm_unreachable_internal("Unexpected opcode", "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 4422)
;
4423 }
4424}
4425
4426/// Given operands for a BinaryOperator, see if we can fold the result.
4427/// If not, this returns null.
4428/// In contrast to SimplifyBinOp, try to use FastMathFlag when folding the
4429/// result. In case we don't need FastMathFlags, simply fall to SimplifyBinOp.
4430static Value *SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
4431 const FastMathFlags &FMF, const SimplifyQuery &Q,
4432 unsigned MaxRecurse) {
4433 switch (Opcode) {
4434 case Instruction::FAdd:
4435 return SimplifyFAddInst(LHS, RHS, FMF, Q, MaxRecurse);
4436 case Instruction::FSub:
4437 return SimplifyFSubInst(LHS, RHS, FMF, Q, MaxRecurse);
4438 case Instruction::FMul:
4439 return SimplifyFMulInst(LHS, RHS, FMF, Q, MaxRecurse);
4440 case Instruction::FDiv:
4441 return SimplifyFDivInst(LHS, RHS, FMF, Q, MaxRecurse);
4442 default:
4443 return SimplifyBinOp(Opcode, LHS, RHS, Q, MaxRecurse);
4444 }
4445}
4446
4447Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
4448 const SimplifyQuery &Q) {
4449 return ::SimplifyBinOp(Opcode, LHS, RHS, Q, RecursionLimit);
4450}
4451
4452Value *llvm::SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
4453 FastMathFlags FMF, const SimplifyQuery &Q) {
4454 return ::SimplifyFPBinOp(Opcode, LHS, RHS, FMF, Q, RecursionLimit);
4455}
4456
4457/// Given operands for a CmpInst, see if we can fold the result.
4458static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
4459 const SimplifyQuery &Q, unsigned MaxRecurse) {
4460 if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
2
Taking false branch
4461 return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
4462 return SimplifyFCmpInst(Predicate, LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3
Calling 'SimplifyFCmpInst'
4463}
4464
4465Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
4466 const SimplifyQuery &Q) {
4467 return ::SimplifyCmpInst(Predicate, LHS, RHS, Q, RecursionLimit);
1
Calling 'SimplifyCmpInst'
4468}
4469
4470static bool IsIdempotent(Intrinsic::ID ID) {
4471 switch (ID) {
4472 default: return false;
4473
4474 // Unary idempotent: f(f(x)) = f(x)
4475 case Intrinsic::fabs:
4476 case Intrinsic::floor:
4477 case Intrinsic::ceil:
4478 case Intrinsic::trunc:
4479 case Intrinsic::rint:
4480 case Intrinsic::nearbyint:
4481 case Intrinsic::round:
4482 case Intrinsic::canonicalize:
4483 return true;
4484 }
4485}
4486
4487static Value *SimplifyRelativeLoad(Constant *Ptr, Constant *Offset,
4488 const DataLayout &DL) {
4489 GlobalValue *PtrSym;
4490 APInt PtrOffset;
4491 if (!IsConstantOffsetFromGlobal(Ptr, PtrSym, PtrOffset, DL))
4492 return nullptr;
4493
4494 Type *Int8PtrTy = Type::getInt8PtrTy(Ptr->getContext());
4495 Type *Int32Ty = Type::getInt32Ty(Ptr->getContext());
4496 Type *Int32PtrTy = Int32Ty->getPointerTo();
4497 Type *Int64Ty = Type::getInt64Ty(Ptr->getContext());
4498
4499 auto *OffsetConstInt = dyn_cast<ConstantInt>(Offset);
4500 if (!OffsetConstInt || OffsetConstInt->getType()->getBitWidth() > 64)
4501 return nullptr;
4502
4503 uint64_t OffsetInt = OffsetConstInt->getSExtValue();
4504 if (OffsetInt % 4 != 0)
4505 return nullptr;
4506
4507 Constant *C = ConstantExpr::getGetElementPtr(
4508 Int32Ty, ConstantExpr::getBitCast(Ptr, Int32PtrTy),
4509 ConstantInt::get(Int64Ty, OffsetInt / 4));
4510 Constant *Loaded = ConstantFoldLoadFromConstPtr(C, Int32Ty, DL);
4511 if (!Loaded)
4512 return nullptr;
4513
4514 auto *LoadedCE = dyn_cast<ConstantExpr>(Loaded);
4515 if (!LoadedCE)
4516 return nullptr;
4517
4518 if (LoadedCE->getOpcode() == Instruction::Trunc) {
4519 LoadedCE = dyn_cast<ConstantExpr>(LoadedCE->getOperand(0));
4520 if (!LoadedCE)
4521 return nullptr;
4522 }
4523
4524 if (LoadedCE->getOpcode() != Instruction::Sub)
4525 return nullptr;
4526
4527 auto *LoadedLHS = dyn_cast<ConstantExpr>(LoadedCE->getOperand(0));
4528 if (!LoadedLHS || LoadedLHS->getOpcode() != Instruction::PtrToInt)
4529 return nullptr;
4530 auto *LoadedLHSPtr = LoadedLHS->getOperand(0);
4531
4532 Constant *LoadedRHS = LoadedCE->getOperand(1);
4533 GlobalValue *LoadedRHSSym;
4534 APInt LoadedRHSOffset;
4535 if (!IsConstantOffsetFromGlobal(LoadedRHS, LoadedRHSSym, LoadedRHSOffset,
4536 DL) ||
4537 PtrSym != LoadedRHSSym || PtrOffset != LoadedRHSOffset)
4538 return nullptr;
4539
4540 return ConstantExpr::getBitCast(LoadedLHSPtr, Int8PtrTy);
4541}
4542
4543static bool maskIsAllZeroOrUndef(Value *Mask) {
4544 auto *ConstMask = dyn_cast<Constant>(Mask);
4545 if (!ConstMask)
4546 return false;
4547 if (ConstMask->isNullValue() || isa<UndefValue>(ConstMask))
4548 return true;
4549 for (unsigned I = 0, E = ConstMask->getType()->getVectorNumElements(); I != E;
4550 ++I) {
4551 if (auto *MaskElt = ConstMask->getAggregateElement(I))
4552 if (MaskElt->isNullValue() || isa<UndefValue>(MaskElt))
4553 continue;
4554 return false;
4555 }
4556 return true;
4557}
4558
4559template <typename IterTy>
4560static Value *SimplifyIntrinsic(Function *F, IterTy ArgBegin, IterTy ArgEnd,
4561 const SimplifyQuery &Q, unsigned MaxRecurse) {
4562 Intrinsic::ID IID = F->getIntrinsicID();
4563 unsigned NumOperands = std::distance(ArgBegin, ArgEnd);
4564
4565 // Unary Ops
4566 if (NumOperands == 1) {
4567 // Perform idempotent optimizations
4568 if (IsIdempotent(IID)) {
4569 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*ArgBegin)) {
4570 if (II->getIntrinsicID() == IID)
4571 return II;
4572 }
4573 }
4574
4575 Value *IIOperand = *ArgBegin;
4576 Value *X;
4577 switch (IID) {
4578 case Intrinsic::fabs: {
4579 if (SignBitMustBeZero(IIOperand, Q.TLI))
4580 return IIOperand;
4581 return nullptr;
4582 }
4583 case Intrinsic::bswap: {
4584 // bswap(bswap(x)) -> x
4585 if (match(IIOperand, m_BSwap(m_Value(X))))
4586 return X;
4587 return nullptr;
4588 }
4589 case Intrinsic::bitreverse: {
4590 // bitreverse(bitreverse(x)) -> x
4591 if (match(IIOperand, m_BitReverse(m_Value(X))))
4592 return X;
4593 return nullptr;
4594 }
4595 case Intrinsic::exp: {
4596 // exp(log(x)) -> x
4597 if (Q.CxtI->hasAllowReassoc() &&
4598 match(IIOperand, m_Intrinsic<Intrinsic::log>(m_Value(X))))
4599 return X;
4600 return nullptr;
4601 }
4602 case Intrinsic::exp2: {
4603 // exp2(log2(x)) -> x
4604 if (Q.CxtI->hasAllowReassoc() &&
4605 match(IIOperand, m_Intrinsic<Intrinsic::log2>(m_Value(X))))
4606 return X;
4607 return nullptr;
4608 }
4609 case Intrinsic::log: {
4610 // log(exp(x)) -> x
4611 if (Q.CxtI->hasAllowReassoc() &&
4612 match(IIOperand, m_Intrinsic<Intrinsic::exp>(m_Value(X))))
4613 return X;
4614 return nullptr;
4615 }
4616 case Intrinsic::log2: {
4617 // log2(exp2(x)) -> x
4618 if (Q.CxtI->hasAllowReassoc() &&
4619 match(IIOperand, m_Intrinsic<Intrinsic::exp2>(m_Value(X)))) {
4620 return X;
4621 }
4622 return nullptr;
4623 }
4624 default:
4625 return nullptr;
4626 }
4627 }
4628
4629 // Binary Ops
4630 if (NumOperands == 2) {
4631 Value *LHS = *ArgBegin;
4632 Value *RHS = *(ArgBegin + 1);
4633 Type *ReturnType = F->getReturnType();
4634
4635 switch (IID) {
4636 case Intrinsic::usub_with_overflow:
4637 case Intrinsic::ssub_with_overflow: {
4638 // X - X -> { 0, false }
4639 if (LHS == RHS)
4640 return Constant::getNullValue(ReturnType);
4641
4642 // X - undef -> undef
4643 // undef - X -> undef
4644 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS))
4645 return UndefValue::get(ReturnType);
4646
4647 return nullptr;
4648 }
4649 case Intrinsic::uadd_with_overflow:
4650 case Intrinsic::sadd_with_overflow: {
4651 // X + undef -> undef
4652 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS))
4653 return UndefValue::get(ReturnType);
4654
4655 return nullptr;
4656 }
4657 case Intrinsic::umul_with_overflow:
4658 case Intrinsic::smul_with_overflow: {
4659 // 0 * X -> { 0, false }
4660 // X * 0 -> { 0, false }
4661 if (match(LHS, m_Zero()) || match(RHS, m_Zero()))
4662 return Constant::getNullValue(ReturnType);
4663
4664 // undef * X -> { 0, false }
4665 // X * undef -> { 0, false }
4666 if (match(LHS, m_Undef()) || match(RHS, m_Undef()))
4667 return Constant::getNullValue(ReturnType);
4668
4669 return nullptr;
4670 }
4671 case Intrinsic::load_relative: {
4672 Constant *C0 = dyn_cast<Constant>(LHS);
4673 Constant *C1 = dyn_cast<Constant>(RHS);
4674 if (C0 && C1)
4675 return SimplifyRelativeLoad(C0, C1, Q.DL);
4676 return nullptr;
4677 }
4678 case Intrinsic::powi:
4679 if (ConstantInt *Power = dyn_cast<ConstantInt>(RHS)) {
4680 // powi(x, 0) -> 1.0
4681 if (Power->isZero())
4682 return ConstantFP::get(LHS->getType(), 1.0);
4683 // powi(x, 1) -> x
4684 if (Power->isOne())
4685 return LHS;
4686 }
4687 return nullptr;
4688 default:
4689 return nullptr;
4690 }
4691 }
4692
4693 // Simplify calls to llvm.masked.load.*
4694 switch (IID) {
4695 case Intrinsic::masked_load: {
4696 Value *MaskArg = ArgBegin[2];
4697 Value *PassthruArg = ArgBegin[3];
4698 // If the mask is all zeros or undef, the "passthru" argument is the result.
4699 if (maskIsAllZeroOrUndef(MaskArg))
4700 return PassthruArg;
4701 return nullptr;
4702 }
4703 default:
4704 return nullptr;
4705 }
4706}
4707
4708template <typename IterTy>
4709static Value *SimplifyCall(ImmutableCallSite CS, Value *V, IterTy ArgBegin,
4710 IterTy ArgEnd, const SimplifyQuery &Q,
4711 unsigned MaxRecurse) {
4712 Type *Ty = V->getType();
4713 if (PointerType *PTy = dyn_cast<PointerType>(Ty))
4714 Ty = PTy->getElementType();
4715 FunctionType *FTy = cast<FunctionType>(Ty);
4716
4717 // call undef -> undef
4718 // call null -> undef
4719 if (isa<UndefValue>(V) || isa<ConstantPointerNull>(V))
4720 return UndefValue::get(FTy->getReturnType());
4721
4722 Function *F = dyn_cast<Function>(V);
4723 if (!F)
4724 return nullptr;
4725
4726 if (F->isIntrinsic())
4727 if (Value *Ret = SimplifyIntrinsic(F, ArgBegin, ArgEnd, Q, MaxRecurse))
4728 return Ret;
4729
4730 if (!canConstantFoldCallTo(CS, F))
4731 return nullptr;
4732
4733 SmallVector<Constant *, 4> ConstantArgs;
4734 ConstantArgs.reserve(ArgEnd - ArgBegin);
4735 for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
4736 Constant *C = dyn_cast<Constant>(*I);
4737 if (!C)
4738 return nullptr;
4739 ConstantArgs.push_back(C);
4740 }
4741
4742 return ConstantFoldCall(CS, F, ConstantArgs, Q.TLI);
4743}
4744
4745Value *llvm::SimplifyCall(ImmutableCallSite CS, Value *V,
4746 User::op_iterator ArgBegin, User::op_iterator ArgEnd,
4747 const SimplifyQuery &Q) {
4748 return ::SimplifyCall(CS, V, ArgBegin, ArgEnd, Q, RecursionLimit);
4749}
4750
4751Value *llvm::SimplifyCall(ImmutableCallSite CS, Value *V,
4752 ArrayRef<Value *> Args, const SimplifyQuery &Q) {
4753 return ::SimplifyCall(CS, V, Args.begin(), Args.end(), Q, RecursionLimit);
4754}
4755
4756Value *llvm::SimplifyCall(ImmutableCallSite ICS, const SimplifyQuery &Q) {
4757 CallSite CS(const_cast<Instruction*>(ICS.getInstruction()));
4758 return ::SimplifyCall(CS, CS.getCalledValue(), CS.arg_begin(), CS.arg_end(),
4759 Q, RecursionLimit);
4760}
4761
4762/// See if we can compute a simplified version of this instruction.
4763/// If not, this returns null.
4764
4765Value *llvm::SimplifyInstruction(Instruction *I, const SimplifyQuery &SQ,
4766 OptimizationRemarkEmitter *ORE) {
4767 const SimplifyQuery Q = SQ.CxtI ? SQ : SQ.getWithInstruction(I);
4768 Value *Result;
4769
4770 switch (I->getOpcode()) {
4771 default:
4772 Result = ConstantFoldInstruction(I, Q.DL, Q.TLI);
4773 break;
4774 case Instruction::FAdd:
4775 Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1),
4776 I->getFastMathFlags(), Q);
4777 break;
4778 case Instruction::Add:
4779 Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
4780 cast<BinaryOperator>(I)->hasNoSignedWrap(),
4781 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), Q);
4782 break;
4783 case Instruction::FSub:
4784 Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1),
4785 I->getFastMathFlags(), Q);
4786 break;
4787 case Instruction::Sub:
4788 Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
4789 cast<BinaryOperator>(I)->hasNoSignedWrap(),
4790 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), Q);
4791 break;
4792 case Instruction::FMul:
4793 Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1),
4794 I->getFastMathFlags(), Q);
4795 break;
4796 case Instruction::Mul:
4797 Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), Q);
4798 break;
4799 case Instruction::SDiv:
4800 Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), Q);
4801 break;
4802 case Instruction::UDiv:
4803 Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), Q);
4804 break;
4805 case Instruction::FDiv:
4806 Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1),
4807 I->getFastMathFlags(), Q);
4808 break;
4809 case Instruction::SRem:
4810 Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), Q);
4811 break;
4812 case Instruction::URem:
4813 Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), Q);
4814 break;
4815 case Instruction::FRem:
4816 Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1),
4817 I->getFastMathFlags(), Q);
4818 break;
4819 case Instruction::Shl:
4820 Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
4821 cast<BinaryOperator>(I)->hasNoSignedWrap(),
4822 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), Q);
4823 break;
4824 case Instruction::LShr:
4825 Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
4826 cast<BinaryOperator>(I)->isExact(), Q);
4827 break;
4828 case Instruction::AShr:
4829 Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
4830 cast<BinaryOperator>(I)->isExact(), Q);
4831 break;
4832 case Instruction::And:
4833 Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), Q);
4834 break;
4835 case Instruction::Or:
4836 Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), Q);
4837 break;
4838 case Instruction::Xor:
4839 Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), Q);
4840 break;
4841 case Instruction::ICmp:
4842 Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(),
4843 I->getOperand(0), I->getOperand(1), Q);
4844 break;
4845 case Instruction::FCmp:
4846 Result =
4847 SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), I->getOperand(0),
4848 I->getOperand(1), I->getFastMathFlags(), Q);
4849 break;
4850 case Instruction::Select:
4851 Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
4852 I->getOperand(2), Q);
4853 break;
4854 case Instruction::GetElementPtr: {
4855 SmallVector<Value *, 8> Ops(I->op_begin(), I->op_end());
4856 Result = SimplifyGEPInst(cast<GetElementPtrInst>(I)->getSourceElementType(),
4857 Ops, Q);
4858 break;
4859 }
4860 case Instruction::InsertValue: {
4861 InsertValueInst *IV = cast<InsertValueInst>(I);
4862 Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
4863 IV->getInsertedValueOperand(),
4864 IV->getIndices(), Q);
4865 break;
4866 }
4867 case Instruction::InsertElement: {
4868 auto *IE = cast<InsertElementInst>(I);
4869 Result = SimplifyInsertElementInst(IE->getOperand(0), IE->getOperand(1),
4870 IE->getOperand(2), Q);
4871 break;
4872 }
4873 case Instruction::ExtractValue: {
4874 auto *EVI = cast<ExtractValueInst>(I);
4875 Result = SimplifyExtractValueInst(EVI->getAggregateOperand(),
4876 EVI->getIndices(), Q);
4877 break;
4878 }
4879 case Instruction::ExtractElement: {
4880 auto *EEI = cast<ExtractElementInst>(I);
4881 Result = SimplifyExtractElementInst(EEI->getVectorOperand(),
4882 EEI->getIndexOperand(), Q);
4883 break;
4884 }
4885 case Instruction::ShuffleVector: {
4886 auto *SVI = cast<ShuffleVectorInst>(I);
4887 Result = SimplifyShuffleVectorInst(SVI->getOperand(0), SVI->getOperand(1),
4888 SVI->getMask(), SVI->getType(), Q);
4889 break;
4890 }
4891 case Instruction::PHI:
4892 Result = SimplifyPHINode(cast<PHINode>(I), Q);
4893 break;
4894 case Instruction::Call: {
4895 CallSite CS(cast<CallInst>(I));
4896 Result = SimplifyCall(CS, Q);
4897 break;
4898 }
4899#define HANDLE_CAST_INST(num, opc, clas) case Instruction::opc:
4900#include "llvm/IR/Instruction.def"
4901#undef HANDLE_CAST_INST
4902 Result =
4903 SimplifyCastInst(I->getOpcode(), I->getOperand(0), I->getType(), Q);
4904 break;
4905 case Instruction::Alloca:
4906 // No simplifications for Alloca and it can't be constant folded.
4907 Result = nullptr;
4908 break;
4909 }
4910
4911 // In general, it is possible for computeKnownBits to determine all bits in a
4912 // value even when the operands are not all constants.
4913 if (!Result && I->getType()->isIntOrIntVectorTy()) {
4914 KnownBits Known = computeKnownBits(I, Q.DL, /*Depth*/ 0, Q.AC, I, Q.DT, ORE);
4915 if (Known.isConstant())
4916 Result = ConstantInt::get(I->getType(), Known.getConstant());
4917 }
4918
4919 /// If called on unreachable code, the above logic may report that the
4920 /// instruction simplified to itself. Make life easier for users by
4921 /// detecting that case here, returning a safe value instead.
4922 return Result == I ? UndefValue::get(I->getType()) : Result;
4923}
4924
4925/// \brief Implementation of recursive simplification through an instruction's
4926/// uses.
4927///
4928/// This is the common implementation of the recursive simplification routines.
4929/// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
4930/// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
4931/// instructions to process and attempt to simplify it using
4932/// InstructionSimplify.
4933///
4934/// This routine returns 'true' only when *it* simplifies something. The passed
4935/// in simplified value does not count toward this.
4936static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
4937 const TargetLibraryInfo *TLI,
4938 const DominatorTree *DT,
4939 AssumptionCache *AC) {
4940 bool Simplified = false;
4941 SmallSetVector<Instruction *, 8> Worklist;
4942 const DataLayout &DL = I->getModule()->getDataLayout();
4943
4944 // If we have an explicit value to collapse to, do that round of the
4945 // simplification loop by hand initially.
4946 if (SimpleV) {
4947 for (User *U : I->users())
4948 if (U != I)
4949 Worklist.insert(cast<Instruction>(U));
4950
4951 // Replace the instruction with its simplified value.
4952 I->replaceAllUsesWith(SimpleV);
4953
4954 // Gracefully handle edge cases where the instruction is not wired into any
4955 // parent block.
4956 if (I->getParent() && !I->isEHPad() && !isa<TerminatorInst>(I) &&
4957 !I->mayHaveSideEffects())
4958 I->eraseFromParent();
4959 } else {
4960 Worklist.insert(I);
4961 }
4962
4963 // Note that we must test the size on each iteration, the worklist can grow.
4964 for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
4965 I = Worklist[Idx];
4966
4967 // See if this instruction simplifies.
4968 SimpleV = SimplifyInstruction(I, {DL, TLI, DT, AC});
4969 if (!SimpleV)
4970 continue;
4971
4972 Simplified = true;
4973
4974 // Stash away all the uses of the old instruction so we can check them for
4975 // recursive simplifications after a RAUW. This is cheaper than checking all
4976 // uses of To on the recursive step in most cases.
4977 for (User *U : I->users())
4978 Worklist.insert(cast<Instruction>(U));
4979
4980 // Replace the instruction with its simplified value.
4981 I->replaceAllUsesWith(SimpleV);
4982
4983 // Gracefully handle edge cases where the instruction is not wired into any
4984 // parent block.
4985 if (I->getParent() && !I->isEHPad() && !isa<TerminatorInst>(I) &&
4986 !I->mayHaveSideEffects())
4987 I->eraseFromParent();
4988 }
4989 return Simplified;
4990}
4991
4992bool llvm::recursivelySimplifyInstruction(Instruction *I,
4993 const TargetLibraryInfo *TLI,
4994 const DominatorTree *DT,
4995 AssumptionCache *AC) {
4996 return replaceAndRecursivelySimplifyImpl(I, nullptr, TLI, DT, AC);
4997}
4998
4999bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
5000 const TargetLibraryInfo *TLI,
5001 const DominatorTree *DT,
5002 AssumptionCache *AC) {
5003 assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!")(static_cast <bool> (I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!"
) ? void (0) : __assert_fail ("I != SimpleV && \"replaceAndRecursivelySimplify(X,X) is not valid!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 5003, __extension__ __PRETTY_FUNCTION__))
;
5004 assert(SimpleV && "Must provide a simplified value.")(static_cast <bool> (SimpleV && "Must provide a simplified value."
) ? void (0) : __assert_fail ("SimpleV && \"Must provide a simplified value.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/Analysis/InstructionSimplify.cpp"
, 5004, __extension__ __PRETTY_FUNCTION__))
;
5005 return replaceAndRecursivelySimplifyImpl(I, SimpleV, TLI, DT, AC);
5006}
5007
5008namespace llvm {
5009const SimplifyQuery getBestSimplifyQuery(Pass &P, Function &F) {
5010 auto *DTWP = P.getAnalysisIfAvailable<DominatorTreeWrapperPass>();
5011 auto *DT = DTWP ? &DTWP->getDomTree() : nullptr;
5012 auto *TLIWP = P.getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
5013 auto *TLI = TLIWP ? &TLIWP->getTLI() : nullptr;
5014 auto *ACWP = P.getAnalysisIfAvailable<AssumptionCacheTracker>();
5015 auto *AC = ACWP ? &ACWP->getAssumptionCache(F) : nullptr;
5016 return {F.getParent()->getDataLayout(), TLI, DT, AC};
5017}
5018
5019const SimplifyQuery getBestSimplifyQuery(LoopStandardAnalysisResults &AR,
5020 const DataLayout &DL) {
5021 return {DL, &AR.TLI, &AR.DT, &AR.AC};
5022}
5023
5024template <class T, class... TArgs>
5025const SimplifyQuery getBestSimplifyQuery(AnalysisManager<T, TArgs...> &AM,
5026 Function &F) {
5027 auto *DT = AM.template getCachedResult<DominatorTreeAnalysis>(F);
5028 auto *TLI = AM.template getCachedResult<TargetLibraryAnalysis>(F);
5029 auto *AC = AM.template getCachedResult<AssumptionAnalysis>(F);
5030 return {F.getParent()->getDataLayout(), TLI, DT, AC};
5031}
5032template const SimplifyQuery getBestSimplifyQuery(AnalysisManager<Function> &,
5033 Function &);
5034}

/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h

1//===- llvm/Instructions.h - Instruction subclass definitions ---*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file exposes the class definitions of all of the subclasses of the
11// Instruction class. This is meant to be an easy way to get access to all
12// instruction subclasses.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_IR_INSTRUCTIONS_H
17#define LLVM_IR_INSTRUCTIONS_H
18
19#include "llvm/ADT/ArrayRef.h"
20#include "llvm/ADT/None.h"
21#include "llvm/ADT/STLExtras.h"
22#include "llvm/ADT/SmallVector.h"
23#include "llvm/ADT/StringRef.h"
24#include "llvm/ADT/Twine.h"
25#include "llvm/ADT/iterator.h"
26#include "llvm/ADT/iterator_range.h"
27#include "llvm/IR/Attributes.h"
28#include "llvm/IR/BasicBlock.h"
29#include "llvm/IR/CallingConv.h"
30#include "llvm/IR/Constant.h"
31#include "llvm/IR/DerivedTypes.h"
32#include "llvm/IR/Function.h"
33#include "llvm/IR/InstrTypes.h"
34#include "llvm/IR/Instruction.h"
35#include "llvm/IR/OperandTraits.h"
36#include "llvm/IR/Type.h"
37#include "llvm/IR/Use.h"
38#include "llvm/IR/User.h"
39#include "llvm/IR/Value.h"
40#include "llvm/Support/AtomicOrdering.h"
41#include "llvm/Support/Casting.h"
42#include "llvm/Support/ErrorHandling.h"
43#include <cassert>
44#include <cstddef>
45#include <cstdint>
46#include <iterator>
47
48namespace llvm {
49
50class APInt;
51class ConstantInt;
52class DataLayout;
53class LLVMContext;
54
55//===----------------------------------------------------------------------===//
56// AllocaInst Class
57//===----------------------------------------------------------------------===//
58
59/// an instruction to allocate memory on the stack
60class AllocaInst : public UnaryInstruction {
61 Type *AllocatedType;
62
63protected:
64 // Note: Instruction needs to be a friend here to call cloneImpl.
65 friend class Instruction;
66
67 AllocaInst *cloneImpl() const;
68
69public:
70 explicit AllocaInst(Type *Ty, unsigned AddrSpace,
71 Value *ArraySize = nullptr,
72 const Twine &Name = "",
73 Instruction *InsertBefore = nullptr);
74 AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize,
75 const Twine &Name, BasicBlock *InsertAtEnd);
76
77 AllocaInst(Type *Ty, unsigned AddrSpace,
78 const Twine &Name, Instruction *InsertBefore = nullptr);
79 AllocaInst(Type *Ty, unsigned AddrSpace,
80 const Twine &Name, BasicBlock *InsertAtEnd);
81
82 AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize, unsigned Align,
83 const Twine &Name = "", Instruction *InsertBefore = nullptr);
84 AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize, unsigned Align,
85 const Twine &Name, BasicBlock *InsertAtEnd);
86
87 /// Return true if there is an allocation size parameter to the allocation
88 /// instruction that is not 1.
89 bool isArrayAllocation() const;
90
91 /// Get the number of elements allocated. For a simple allocation of a single
92 /// element, this will return a constant 1 value.
93 const Value *getArraySize() const { return getOperand(0); }
94 Value *getArraySize() { return getOperand(0); }
95
96 /// Overload to return most specific pointer type.
97 PointerType *getType() const {
98 return cast<PointerType>(Instruction::getType());
99 }
100
101 /// Return the type that is being allocated by the instruction.
102 Type *getAllocatedType() const { return AllocatedType; }
103 /// for use only in special circumstances that need to generically
104 /// transform a whole instruction (eg: IR linking and vectorization).
105 void setAllocatedType(Type *Ty) { AllocatedType = Ty; }
106
107 /// Return the alignment of the memory that is being allocated by the
108 /// instruction.
109 unsigned getAlignment() const {
110 return (1u << (getSubclassDataFromInstruction() & 31)) >> 1;
111 }
112 void setAlignment(unsigned Align);
113
114 /// Return true if this alloca is in the entry block of the function and is a
115 /// constant size. If so, the code generator will fold it into the
116 /// prolog/epilog code, so it is basically free.
117 bool isStaticAlloca() const;
118
119 /// Return true if this alloca is used as an inalloca argument to a call. Such
120 /// allocas are never considered static even if they are in the entry block.
121 bool isUsedWithInAlloca() const {
122 return getSubclassDataFromInstruction() & 32;
123 }
124
125 /// Specify whether this alloca is used to represent the arguments to a call.
126 void setUsedWithInAlloca(bool V) {
127 setInstructionSubclassData((getSubclassDataFromInstruction() & ~32) |
128 (V ? 32 : 0));
129 }
130
131 /// Return true if this alloca is used as a swifterror argument to a call.
132 bool isSwiftError() const {
133 return getSubclassDataFromInstruction() & 64;
134 }
135
136 /// Specify whether this alloca is used to represent a swifterror.
137 void setSwiftError(bool V) {
138 setInstructionSubclassData((getSubclassDataFromInstruction() & ~64) |
139 (V ? 64 : 0));
140 }
141
142 // Methods for support type inquiry through isa, cast, and dyn_cast:
143 static bool classof(const Instruction *I) {
144 return (I->getOpcode() == Instruction::Alloca);
145 }
146 static bool classof(const Value *V) {
147 return isa<Instruction>(V) && classof(cast<Instruction>(V));
148 }
149
150private:
151 // Shadow Instruction::setInstructionSubclassData with a private forwarding
152 // method so that subclasses cannot accidentally use it.
153 void setInstructionSubclassData(unsigned short D) {
154 Instruction::setInstructionSubclassData(D);
155 }
156};
157
158//===----------------------------------------------------------------------===//
159// LoadInst Class
160//===----------------------------------------------------------------------===//
161
162/// An instruction for reading from memory. This uses the SubclassData field in
163/// Value to store whether or not the load is volatile.
164class LoadInst : public UnaryInstruction {
165 void AssertOK();
166
167protected:
168 // Note: Instruction needs to be a friend here to call cloneImpl.
169 friend class Instruction;
170
171 LoadInst *cloneImpl() const;
172
173public:
174 LoadInst(Value *Ptr, const Twine &NameStr, Instruction *InsertBefore);
175 LoadInst(Value *Ptr, const Twine &NameStr, BasicBlock *InsertAtEnd);
176 LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile = false,
177 Instruction *InsertBefore = nullptr);
178 LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile = false,
179 Instruction *InsertBefore = nullptr)
180 : LoadInst(cast<PointerType>(Ptr->getType())->getElementType(), Ptr,
181 NameStr, isVolatile, InsertBefore) {}
182 LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
183 BasicBlock *InsertAtEnd);
184 LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile, unsigned Align,
185 Instruction *InsertBefore = nullptr)
186 : LoadInst(cast<PointerType>(Ptr->getType())->getElementType(), Ptr,
187 NameStr, isVolatile, Align, InsertBefore) {}
188 LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile,
189 unsigned Align, Instruction *InsertBefore = nullptr);
190 LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
191 unsigned Align, BasicBlock *InsertAtEnd);
192 LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile, unsigned Align,
193 AtomicOrdering Order, SyncScope::ID SSID = SyncScope::System,
194 Instruction *InsertBefore = nullptr)
195 : LoadInst(cast<PointerType>(Ptr->getType())->getElementType(), Ptr,
196 NameStr, isVolatile, Align, Order, SSID, InsertBefore) {}
197 LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile,
198 unsigned Align, AtomicOrdering Order,
199 SyncScope::ID SSID = SyncScope::System,
200 Instruction *InsertBefore = nullptr);
201 LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
202 unsigned Align, AtomicOrdering Order, SyncScope::ID SSID,
203 BasicBlock *InsertAtEnd);
204 LoadInst(Value *Ptr, const char *NameStr, Instruction *InsertBefore);
205 LoadInst(Value *Ptr, const char *NameStr, BasicBlock *InsertAtEnd);
206 LoadInst(Type *Ty, Value *Ptr, const char *NameStr = nullptr,
207 bool isVolatile = false, Instruction *InsertBefore = nullptr);
208 explicit LoadInst(Value *Ptr, const char *NameStr = nullptr,
209 bool isVolatile = false,
210 Instruction *InsertBefore = nullptr)
211 : LoadInst(cast<PointerType>(Ptr->getType())->getElementType(), Ptr,
212 NameStr, isVolatile, InsertBefore) {}
213 LoadInst(Value *Ptr, const char *NameStr, bool isVolatile,
214 BasicBlock *InsertAtEnd);
215
216 /// Return true if this is a load from a volatile memory location.
217 bool isVolatile() const { return getSubclassDataFromInstruction() & 1; }
218
219 /// Specify whether this is a volatile load or not.
220 void setVolatile(bool V) {
221 setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
222 (V ? 1 : 0));
223 }
224
225 /// Return the alignment of the access that is being performed.
226 unsigned getAlignment() const {
227 return (1 << ((getSubclassDataFromInstruction() >> 1) & 31)) >> 1;
228 }
229
230 void setAlignment(unsigned Align);
231
232 /// Returns the ordering constraint of this load instruction.
233 AtomicOrdering getOrdering() const {
234 return AtomicOrdering((getSubclassDataFromInstruction() >> 7) & 7);
235 }
236
237 /// Sets the ordering constraint of this load instruction. May not be Release
238 /// or AcquireRelease.
239 void setOrdering(AtomicOrdering Ordering) {
240 setInstructionSubclassData((getSubclassDataFromInstruction() & ~(7 << 7)) |
241 ((unsigned)Ordering << 7));
242 }
243
244 /// Returns the synchronization scope ID of this load instruction.
245 SyncScope::ID getSyncScopeID() const {
246 return SSID;
247 }
248
249 /// Sets the synchronization scope ID of this load instruction.
250 void setSyncScopeID(SyncScope::ID SSID) {
251 this->SSID = SSID;
252 }
253
254 /// Sets the ordering constraint and the synchronization scope ID of this load
255 /// instruction.
256 void setAtomic(AtomicOrdering Ordering,
257 SyncScope::ID SSID = SyncScope::System) {
258 setOrdering(Ordering);
259 setSyncScopeID(SSID);
260 }
261
262 bool isSimple() const { return !isAtomic() && !isVolatile(); }
263
264 bool isUnordered() const {
265 return (getOrdering() == AtomicOrdering::NotAtomic ||
266 getOrdering() == AtomicOrdering::Unordered) &&
267 !isVolatile();
268 }
269
270 Value *getPointerOperand() { return getOperand(0); }
271 const Value *getPointerOperand() const { return getOperand(0); }
272 static unsigned getPointerOperandIndex() { return 0U; }
273 Type *getPointerOperandType() const { return getPointerOperand()->getType(); }
274
275 /// Returns the address space of the pointer operand.
276 unsigned getPointerAddressSpace() const {
277 return getPointerOperandType()->getPointerAddressSpace();
278 }
279
280 // Methods for support type inquiry through isa, cast, and dyn_cast:
281 static bool classof(const Instruction *I) {
282 return I->getOpcode() == Instruction::Load;
283 }
284 static bool classof(const Value *V) {
285 return isa<Instruction>(V) && classof(cast<Instruction>(V));
286 }
287
288private:
289 // Shadow Instruction::setInstructionSubclassData with a private forwarding
290 // method so that subclasses cannot accidentally use it.
291 void setInstructionSubclassData(unsigned short D) {
292 Instruction::setInstructionSubclassData(D);
293 }
294
295 /// The synchronization scope ID of this load instruction. Not quite enough
296 /// room in SubClassData for everything, so synchronization scope ID gets its
297 /// own field.
298 SyncScope::ID SSID;
299};
300
301//===----------------------------------------------------------------------===//
302// StoreInst Class
303//===----------------------------------------------------------------------===//
304
305/// An instruction for storing to memory.
306class StoreInst : public Instruction {
307 void AssertOK();
308
309protected:
310 // Note: Instruction needs to be a friend here to call cloneImpl.
311 friend class Instruction;
312
313 StoreInst *cloneImpl() const;
314
315public:
316 StoreInst(Value *Val, Value *Ptr, Instruction *InsertBefore);
317 StoreInst(Value *Val, Value *Ptr, BasicBlock *InsertAtEnd);
318 StoreInst(Value *Val, Value *Ptr, bool isVolatile = false,
319 Instruction *InsertBefore = nullptr);
320 StoreInst(Value *Val, Value *Ptr, bool isVolatile, BasicBlock *InsertAtEnd);
321 StoreInst(Value *Val, Value *Ptr, bool isVolatile,
322 unsigned Align, Instruction *InsertBefore = nullptr);
323 StoreInst(Value *Val, Value *Ptr, bool isVolatile,
324 unsigned Align, BasicBlock *InsertAtEnd);
325 StoreInst(Value *Val, Value *Ptr, bool isVolatile,
326 unsigned Align, AtomicOrdering Order,
327 SyncScope::ID SSID = SyncScope::System,
328 Instruction *InsertBefore = nullptr);
329 StoreInst(Value *Val, Value *Ptr, bool isVolatile,
330 unsigned Align, AtomicOrdering Order, SyncScope::ID SSID,
331 BasicBlock *InsertAtEnd);
332
333 // allocate space for exactly two operands
334 void *operator new(size_t s) {
335 return User::operator new(s, 2);
336 }
337
338 /// Return true if this is a store to a volatile memory location.
339 bool isVolatile() const { return getSubclassDataFromInstruction() & 1; }
340
341 /// Specify whether this is a volatile store or not.
342 void setVolatile(bool V) {
343 setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
344 (V ? 1 : 0));
345 }
346
347 /// Transparently provide more efficient getOperand methods.
348 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void
setOperand(unsigned, Value*); inline op_iterator op_begin();
inline const_op_iterator op_begin() const; inline op_iterator
op_end(); inline const_op_iterator op_end() const; protected
: template <int> inline Use &Op(); template <int
> inline const Use &Op() const; public: inline unsigned
getNumOperands() const
;
349
350 /// Return the alignment of the access that is being performed
351 unsigned getAlignment() const {
352 return (1 << ((getSubclassDataFromInstruction() >> 1) & 31)) >> 1;
353 }
354
355 void setAlignment(unsigned Align);
356
357 /// Returns the ordering constraint of this store instruction.
358 AtomicOrdering getOrdering() const {
359 return AtomicOrdering((getSubclassDataFromInstruction() >> 7) & 7);
360 }
361
362 /// Sets the ordering constraint of this store instruction. May not be
363 /// Acquire or AcquireRelease.
364 void setOrdering(AtomicOrdering Ordering) {
365 setInstructionSubclassData((getSubclassDataFromInstruction() & ~(7 << 7)) |
366 ((unsigned)Ordering << 7));
367 }
368
369 /// Returns the synchronization scope ID of this store instruction.
370 SyncScope::ID getSyncScopeID() const {
371 return SSID;
372 }
373
374 /// Sets the synchronization scope ID of this store instruction.
375 void setSyncScopeID(SyncScope::ID SSID) {
376 this->SSID = SSID;
377 }
378
379 /// Sets the ordering constraint and the synchronization scope ID of this
380 /// store instruction.
381 void setAtomic(AtomicOrdering Ordering,
382 SyncScope::ID SSID = SyncScope::System) {
383 setOrdering(Ordering);
384 setSyncScopeID(SSID);
385 }
386
387 bool isSimple() const { return !isAtomic() && !isVolatile(); }
388
389 bool isUnordered() const {
390 return (getOrdering() == AtomicOrdering::NotAtomic ||
391 getOrdering() == AtomicOrdering::Unordered) &&
392 !isVolatile();
393 }
394
395 Value *getValueOperand() { return getOperand(0); }
396 const Value *getValueOperand() const { return getOperand(0); }
397
398 Value *getPointerOperand() { return getOperand(1); }
399 const Value *getPointerOperand() const { return getOperand(1); }
400 static unsigned getPointerOperandIndex() { return 1U; }
401 Type *getPointerOperandType() const { return getPointerOperand()->getType(); }
402
403 /// Returns the address space of the pointer operand.
404 unsigned getPointerAddressSpace() const {
405 return getPointerOperandType()->getPointerAddressSpace();
406 }
407
408 // Methods for support type inquiry through isa, cast, and dyn_cast:
409 static bool classof(const Instruction *I) {
410 return I->getOpcode() == Instruction::Store;
411 }
412 static bool classof(const Value *V) {
413 return isa<Instruction>(V) && classof(cast<Instruction>(V));
414 }
415
416private:
417 // Shadow Instruction::setInstructionSubclassData with a private forwarding
418 // method so that subclasses cannot accidentally use it.
419 void setInstructionSubclassData(unsigned short D) {
420 Instruction::setInstructionSubclassData(D);
421 }
422
423 /// The synchronization scope ID of this store instruction. Not quite enough
424 /// room in SubClassData for everything, so synchronization scope ID gets its
425 /// own field.
426 SyncScope::ID SSID;
427};
428
429template <>
430struct OperandTraits<StoreInst> : public FixedNumOperandTraits<StoreInst, 2> {
431};
432
433DEFINE_TRANSPARENT_OPERAND_ACCESSORS(StoreInst, Value)StoreInst::op_iterator StoreInst::op_begin() { return OperandTraits
<StoreInst>::op_begin(this); } StoreInst::const_op_iterator
StoreInst::op_begin() const { return OperandTraits<StoreInst
>::op_begin(const_cast<StoreInst*>(this)); } StoreInst
::op_iterator StoreInst::op_end() { return OperandTraits<StoreInst
>::op_end(this); } StoreInst::const_op_iterator StoreInst::
op_end() const { return OperandTraits<StoreInst>::op_end
(const_cast<StoreInst*>(this)); } Value *StoreInst::getOperand
(unsigned i_nocapture) const { (static_cast <bool> (i_nocapture
< OperandTraits<StoreInst>::operands(this) &&
"getOperand() out of range!") ? void (0) : __assert_fail ("i_nocapture < OperandTraits<StoreInst>::operands(this) && \"getOperand() out of range!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 433, __extension__ __PRETTY_FUNCTION__)); return cast_or_null
<Value>( OperandTraits<StoreInst>::op_begin(const_cast
<StoreInst*>(this))[i_nocapture].get()); } void StoreInst
::setOperand(unsigned i_nocapture, Value *Val_nocapture) { (static_cast
<bool> (i_nocapture < OperandTraits<StoreInst>
::operands(this) && "setOperand() out of range!") ? void
(0) : __assert_fail ("i_nocapture < OperandTraits<StoreInst>::operands(this) && \"setOperand() out of range!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 433, __extension__ __PRETTY_FUNCTION__)); OperandTraits<
StoreInst>::op_begin(this)[i_nocapture] = Val_nocapture; }
unsigned StoreInst::getNumOperands() const { return OperandTraits
<StoreInst>::operands(this); } template <int Idx_nocapture
> Use &StoreInst::Op() { return this->OpFrom<Idx_nocapture
>(this); } template <int Idx_nocapture> const Use &
StoreInst::Op() const { return this->OpFrom<Idx_nocapture
>(this); }
434
435//===----------------------------------------------------------------------===//
436// FenceInst Class
437//===----------------------------------------------------------------------===//
438
439/// An instruction for ordering other memory operations.
440class FenceInst : public Instruction {
441 void Init(AtomicOrdering Ordering, SyncScope::ID SSID);
442
443protected:
444 // Note: Instruction needs to be a friend here to call cloneImpl.
445 friend class Instruction;
446
447 FenceInst *cloneImpl() const;
448
449public:
450 // Ordering may only be Acquire, Release, AcquireRelease, or
451 // SequentiallyConsistent.
452 FenceInst(LLVMContext &C, AtomicOrdering Ordering,
453 SyncScope::ID SSID = SyncScope::System,
454 Instruction *InsertBefore = nullptr);
455 FenceInst(LLVMContext &C, AtomicOrdering Ordering, SyncScope::ID SSID,
456 BasicBlock *InsertAtEnd);
457
458 // allocate space for exactly zero operands
459 void *operator new(size_t s) {
460 return User::operator new(s, 0);
461 }
462
463 /// Returns the ordering constraint of this fence instruction.
464 AtomicOrdering getOrdering() const {
465 return AtomicOrdering(getSubclassDataFromInstruction() >> 1);
466 }
467
468 /// Sets the ordering constraint of this fence instruction. May only be
469 /// Acquire, Release, AcquireRelease, or SequentiallyConsistent.
470 void setOrdering(AtomicOrdering Ordering) {
471 setInstructionSubclassData((getSubclassDataFromInstruction() & 1) |
472 ((unsigned)Ordering << 1));
473 }
474
475 /// Returns the synchronization scope ID of this fence instruction.
476 SyncScope::ID getSyncScopeID() const {
477 return SSID;
478 }
479
480 /// Sets the synchronization scope ID of this fence instruction.
481 void setSyncScopeID(SyncScope::ID SSID) {
482 this->SSID = SSID;
483 }
484
485 // Methods for support type inquiry through isa, cast, and dyn_cast:
486 static bool classof(const Instruction *I) {
487 return I->getOpcode() == Instruction::Fence;
488 }
489 static bool classof(const Value *V) {
490 return isa<Instruction>(V) && classof(cast<Instruction>(V));
491 }
492
493private:
494 // Shadow Instruction::setInstructionSubclassData with a private forwarding
495 // method so that subclasses cannot accidentally use it.
496 void setInstructionSubclassData(unsigned short D) {
497 Instruction::setInstructionSubclassData(D);
498 }
499
500 /// The synchronization scope ID of this fence instruction. Not quite enough
501 /// room in SubClassData for everything, so synchronization scope ID gets its
502 /// own field.
503 SyncScope::ID SSID;
504};
505
506//===----------------------------------------------------------------------===//
507// AtomicCmpXchgInst Class
508//===----------------------------------------------------------------------===//
509
510/// an instruction that atomically checks whether a
511/// specified value is in a memory location, and, if it is, stores a new value
512/// there. Returns the value that was loaded.
513///
514class AtomicCmpXchgInst : public Instruction {
515 void Init(Value *Ptr, Value *Cmp, Value *NewVal,
516 AtomicOrdering SuccessOrdering, AtomicOrdering FailureOrdering,
517 SyncScope::ID SSID);
518
519protected:
520 // Note: Instruction needs to be a friend here to call cloneImpl.
521 friend class Instruction;
522
523 AtomicCmpXchgInst *cloneImpl() const;
524
525public:
526 AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
527 AtomicOrdering SuccessOrdering,
528 AtomicOrdering FailureOrdering,
529 SyncScope::ID SSID, Instruction *InsertBefore = nullptr);
530 AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
531 AtomicOrdering SuccessOrdering,
532 AtomicOrdering FailureOrdering,
533 SyncScope::ID SSID, BasicBlock *InsertAtEnd);
534
535 // allocate space for exactly three operands
536 void *operator new(size_t s) {
537 return User::operator new(s, 3);
538 }
539
540 /// Return true if this is a cmpxchg from a volatile memory
541 /// location.
542 ///
543 bool isVolatile() const {
544 return getSubclassDataFromInstruction() & 1;
545 }
546
547 /// Specify whether this is a volatile cmpxchg.
548 ///
549 void setVolatile(bool V) {
550 setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
551 (unsigned)V);
552 }
553
554 /// Return true if this cmpxchg may spuriously fail.
555 bool isWeak() const {
556 return getSubclassDataFromInstruction() & 0x100;
557 }
558
559 void setWeak(bool IsWeak) {
560 setInstructionSubclassData((getSubclassDataFromInstruction() & ~0x100) |
561 (IsWeak << 8));
562 }
563
564 /// Transparently provide more efficient getOperand methods.
565 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void
setOperand(unsigned, Value*); inline op_iterator op_begin();
inline const_op_iterator op_begin() const; inline op_iterator
op_end(); inline const_op_iterator op_end() const; protected
: template <int> inline Use &Op(); template <int
> inline const Use &Op() const; public: inline unsigned
getNumOperands() const
;
566
567 /// Returns the success ordering constraint of this cmpxchg instruction.
568 AtomicOrdering getSuccessOrdering() const {
569 return AtomicOrdering((getSubclassDataFromInstruction() >> 2) & 7);
570 }
571
572 /// Sets the success ordering constraint of this cmpxchg instruction.
573 void setSuccessOrdering(AtomicOrdering Ordering) {
574 assert(Ordering != AtomicOrdering::NotAtomic &&(static_cast <bool> (Ordering != AtomicOrdering::NotAtomic
&& "CmpXchg instructions can only be atomic.") ? void
(0) : __assert_fail ("Ordering != AtomicOrdering::NotAtomic && \"CmpXchg instructions can only be atomic.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 575, __extension__ __PRETTY_FUNCTION__))
575 "CmpXchg instructions can only be atomic.")(static_cast <bool> (Ordering != AtomicOrdering::NotAtomic
&& "CmpXchg instructions can only be atomic.") ? void
(0) : __assert_fail ("Ordering != AtomicOrdering::NotAtomic && \"CmpXchg instructions can only be atomic.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 575, __extension__ __PRETTY_FUNCTION__))
;
576 setInstructionSubclassData((getSubclassDataFromInstruction() & ~0x1c) |
577 ((unsigned)Ordering << 2));
578 }
579
580 /// Returns the failure ordering constraint of this cmpxchg instruction.
581 AtomicOrdering getFailureOrdering() const {
582 return AtomicOrdering((getSubclassDataFromInstruction() >> 5) & 7);
583 }
584
585 /// Sets the failure ordering constraint of this cmpxchg instruction.
586 void setFailureOrdering(AtomicOrdering Ordering) {
587 assert(Ordering != AtomicOrdering::NotAtomic &&(static_cast <bool> (Ordering != AtomicOrdering::NotAtomic
&& "CmpXchg instructions can only be atomic.") ? void
(0) : __assert_fail ("Ordering != AtomicOrdering::NotAtomic && \"CmpXchg instructions can only be atomic.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 588, __extension__ __PRETTY_FUNCTION__))
588 "CmpXchg instructions can only be atomic.")(static_cast <bool> (Ordering != AtomicOrdering::NotAtomic
&& "CmpXchg instructions can only be atomic.") ? void
(0) : __assert_fail ("Ordering != AtomicOrdering::NotAtomic && \"CmpXchg instructions can only be atomic.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 588, __extension__ __PRETTY_FUNCTION__))
;
589 setInstructionSubclassData((getSubclassDataFromInstruction() & ~0xe0) |
590 ((unsigned)Ordering << 5));
591 }
592
593 /// Returns the synchronization scope ID of this cmpxchg instruction.
594 SyncScope::ID getSyncScopeID() const {
595 return SSID;
596 }
597
598 /// Sets the synchronization scope ID of this cmpxchg instruction.
599 void setSyncScopeID(SyncScope::ID SSID) {
600 this->SSID = SSID;
601 }
602
603 Value *getPointerOperand() { return getOperand(0); }
604 const Value *getPointerOperand() const { return getOperand(0); }
605 static unsigned getPointerOperandIndex() { return 0U; }
606
607 Value *getCompareOperand() { return getOperand(1); }
608 const Value *getCompareOperand() const { return getOperand(1); }
609
610 Value *getNewValOperand() { return getOperand(2); }
611 const Value *getNewValOperand() const { return getOperand(2); }
612
613 /// Returns the address space of the pointer operand.
614 unsigned getPointerAddressSpace() const {
615 return getPointerOperand()->getType()->getPointerAddressSpace();
616 }
617
618 /// Returns the strongest permitted ordering on failure, given the
619 /// desired ordering on success.
620 ///
621 /// If the comparison in a cmpxchg operation fails, there is no atomic store
622 /// so release semantics cannot be provided. So this function drops explicit
623 /// Release requests from the AtomicOrdering. A SequentiallyConsistent
624 /// operation would remain SequentiallyConsistent.
625 static AtomicOrdering
626 getStrongestFailureOrdering(AtomicOrdering SuccessOrdering) {
627 switch (SuccessOrdering) {
628 default:
629 llvm_unreachable("invalid cmpxchg success ordering")::llvm::llvm_unreachable_internal("invalid cmpxchg success ordering"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 629)
;
630 case AtomicOrdering::Release:
631 case AtomicOrdering::Monotonic:
632 return AtomicOrdering::Monotonic;
633 case AtomicOrdering::AcquireRelease:
634 case AtomicOrdering::Acquire:
635 return AtomicOrdering::Acquire;
636 case AtomicOrdering::SequentiallyConsistent:
637 return AtomicOrdering::SequentiallyConsistent;
638 }
639 }
640
641 // Methods for support type inquiry through isa, cast, and dyn_cast:
642 static bool classof(const Instruction *I) {
643 return I->getOpcode() == Instruction::AtomicCmpXchg;
644 }
645 static bool classof(const Value *V) {
646 return isa<Instruction>(V) && classof(cast<Instruction>(V));
647 }
648
649private:
650 // Shadow Instruction::setInstructionSubclassData with a private forwarding
651 // method so that subclasses cannot accidentally use it.
652 void setInstructionSubclassData(unsigned short D) {
653 Instruction::setInstructionSubclassData(D);
654 }
655
656 /// The synchronization scope ID of this cmpxchg instruction. Not quite
657 /// enough room in SubClassData for everything, so synchronization scope ID
658 /// gets its own field.
659 SyncScope::ID SSID;
660};
661
662template <>
663struct OperandTraits<AtomicCmpXchgInst> :
664 public FixedNumOperandTraits<AtomicCmpXchgInst, 3> {
665};
666
667DEFINE_TRANSPARENT_OPERAND_ACCESSORS(AtomicCmpXchgInst, Value)AtomicCmpXchgInst::op_iterator AtomicCmpXchgInst::op_begin() {
return OperandTraits<AtomicCmpXchgInst>::op_begin(this
); } AtomicCmpXchgInst::const_op_iterator AtomicCmpXchgInst::
op_begin() const { return OperandTraits<AtomicCmpXchgInst>
::op_begin(const_cast<AtomicCmpXchgInst*>(this)); } AtomicCmpXchgInst
::op_iterator AtomicCmpXchgInst::op_end() { return OperandTraits
<AtomicCmpXchgInst>::op_end(this); } AtomicCmpXchgInst::
const_op_iterator AtomicCmpXchgInst::op_end() const { return OperandTraits
<AtomicCmpXchgInst>::op_end(const_cast<AtomicCmpXchgInst
*>(this)); } Value *AtomicCmpXchgInst::getOperand(unsigned
i_nocapture) const { (static_cast <bool> (i_nocapture <
OperandTraits<AtomicCmpXchgInst>::operands(this) &&
"getOperand() out of range!") ? void (0) : __assert_fail ("i_nocapture < OperandTraits<AtomicCmpXchgInst>::operands(this) && \"getOperand() out of range!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 667, __extension__ __PRETTY_FUNCTION__)); return cast_or_null
<Value>( OperandTraits<AtomicCmpXchgInst>::op_begin
(const_cast<AtomicCmpXchgInst*>(this))[i_nocapture].get
()); } void AtomicCmpXchgInst::setOperand(unsigned i_nocapture
, Value *Val_nocapture) { (static_cast <bool> (i_nocapture
< OperandTraits<AtomicCmpXchgInst>::operands(this) &&
"setOperand() out of range!") ? void (0) : __assert_fail ("i_nocapture < OperandTraits<AtomicCmpXchgInst>::operands(this) && \"setOperand() out of range!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 667, __extension__ __PRETTY_FUNCTION__)); OperandTraits<
AtomicCmpXchgInst>::op_begin(this)[i_nocapture] = Val_nocapture
; } unsigned AtomicCmpXchgInst::getNumOperands() const { return
OperandTraits<AtomicCmpXchgInst>::operands(this); } template
<int Idx_nocapture> Use &AtomicCmpXchgInst::Op() {
return this->OpFrom<Idx_nocapture>(this); } template
<int Idx_nocapture> const Use &AtomicCmpXchgInst::
Op() const { return this->OpFrom<Idx_nocapture>(this
); }
668
669//===----------------------------------------------------------------------===//
670// AtomicRMWInst Class
671//===----------------------------------------------------------------------===//
672
673/// an instruction that atomically reads a memory location,
674/// combines it with another value, and then stores the result back. Returns
675/// the old value.
676///
677class AtomicRMWInst : public Instruction {
678protected:
679 // Note: Instruction needs to be a friend here to call cloneImpl.
680 friend class Instruction;
681
682 AtomicRMWInst *cloneImpl() const;
683
684public:
685 /// This enumeration lists the possible modifications atomicrmw can make. In
686 /// the descriptions, 'p' is the pointer to the instruction's memory location,
687 /// 'old' is the initial value of *p, and 'v' is the other value passed to the
688 /// instruction. These instructions always return 'old'.
689 enum BinOp {
690 /// *p = v
691 Xchg,
692 /// *p = old + v
693 Add,
694 /// *p = old - v
695 Sub,
696 /// *p = old & v
697 And,
698 /// *p = ~(old & v)
699 Nand,
700 /// *p = old | v
701 Or,
702 /// *p = old ^ v
703 Xor,
704 /// *p = old >signed v ? old : v
705 Max,
706 /// *p = old <signed v ? old : v
707 Min,
708 /// *p = old >unsigned v ? old : v
709 UMax,
710 /// *p = old <unsigned v ? old : v
711 UMin,
712
713 FIRST_BINOP = Xchg,
714 LAST_BINOP = UMin,
715 BAD_BINOP
716 };
717
718 AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
719 AtomicOrdering Ordering, SyncScope::ID SSID,
720 Instruction *InsertBefore = nullptr);
721 AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
722 AtomicOrdering Ordering, SyncScope::ID SSID,
723 BasicBlock *InsertAtEnd);
724
725 // allocate space for exactly two operands
726 void *operator new(size_t s) {
727 return User::operator new(s, 2);
728 }
729
730 BinOp getOperation() const {
731 return static_cast<BinOp>(getSubclassDataFromInstruction() >> 5);
732 }
733
734 void setOperation(BinOp Operation) {
735 unsigned short SubclassData = getSubclassDataFromInstruction();
736 setInstructionSubclassData((SubclassData & 31) |
737 (Operation << 5));
738 }
739
740 /// Return true if this is a RMW on a volatile memory location.
741 ///
742 bool isVolatile() const {
743 return getSubclassDataFromInstruction() & 1;
744 }
745
746 /// Specify whether this is a volatile RMW or not.
747 ///
748 void setVolatile(bool V) {
749 setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
750 (unsigned)V);
751 }
752
753 /// Transparently provide more efficient getOperand methods.
754 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void
setOperand(unsigned, Value*); inline op_iterator op_begin();
inline const_op_iterator op_begin() const; inline op_iterator
op_end(); inline const_op_iterator op_end() const; protected
: template <int> inline Use &Op(); template <int
> inline const Use &Op() const; public: inline unsigned
getNumOperands() const
;
755
756 /// Returns the ordering constraint of this rmw instruction.
757 AtomicOrdering getOrdering() const {
758 return AtomicOrdering((getSubclassDataFromInstruction() >> 2) & 7);
759 }
760
761 /// Sets the ordering constraint of this rmw instruction.
762 void setOrdering(AtomicOrdering Ordering) {
763 assert(Ordering != AtomicOrdering::NotAtomic &&(static_cast <bool> (Ordering != AtomicOrdering::NotAtomic
&& "atomicrmw instructions can only be atomic.") ? void
(0) : __assert_fail ("Ordering != AtomicOrdering::NotAtomic && \"atomicrmw instructions can only be atomic.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 764, __extension__ __PRETTY_FUNCTION__))
764 "atomicrmw instructions can only be atomic.")(static_cast <bool> (Ordering != AtomicOrdering::NotAtomic
&& "atomicrmw instructions can only be atomic.") ? void
(0) : __assert_fail ("Ordering != AtomicOrdering::NotAtomic && \"atomicrmw instructions can only be atomic.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 764, __extension__ __PRETTY_FUNCTION__))
;
765 setInstructionSubclassData((getSubclassDataFromInstruction() & ~(7 << 2)) |
766 ((unsigned)Ordering << 2));
767 }
768
769 /// Returns the synchronization scope ID of this rmw instruction.
770 SyncScope::ID getSyncScopeID() const {
771 return SSID;
772 }
773
774 /// Sets the synchronization scope ID of this rmw instruction.
775 void setSyncScopeID(SyncScope::ID SSID) {
776 this->SSID = SSID;
777 }
778
779 Value *getPointerOperand() { return getOperand(0); }
780 const Value *getPointerOperand() const { return getOperand(0); }
781 static unsigned getPointerOperandIndex() { return 0U; }
782
783 Value *getValOperand() { return getOperand(1); }
784 const Value *getValOperand() const { return getOperand(1); }
785
786 /// Returns the address space of the pointer operand.
787 unsigned getPointerAddressSpace() const {
788 return getPointerOperand()->getType()->getPointerAddressSpace();
789 }
790
791 // Methods for support type inquiry through isa, cast, and dyn_cast:
792 static bool classof(const Instruction *I) {
793 return I->getOpcode() == Instruction::AtomicRMW;
794 }
795 static bool classof(const Value *V) {
796 return isa<Instruction>(V) && classof(cast<Instruction>(V));
797 }
798
799private:
800 void Init(BinOp Operation, Value *Ptr, Value *Val,
801 AtomicOrdering Ordering, SyncScope::ID SSID);
802
803 // Shadow Instruction::setInstructionSubclassData with a private forwarding
804 // method so that subclasses cannot accidentally use it.
805 void setInstructionSubclassData(unsigned short D) {
806 Instruction::setInstructionSubclassData(D);
807 }
808
809 /// The synchronization scope ID of this rmw instruction. Not quite enough
810 /// room in SubClassData for everything, so synchronization scope ID gets its
811 /// own field.
812 SyncScope::ID SSID;
813};
814
815template <>
816struct OperandTraits<AtomicRMWInst>
817 : public FixedNumOperandTraits<AtomicRMWInst,2> {
818};
819
820DEFINE_TRANSPARENT_OPERAND_ACCESSORS(AtomicRMWInst, Value)AtomicRMWInst::op_iterator AtomicRMWInst::op_begin() { return
OperandTraits<AtomicRMWInst>::op_begin(this); } AtomicRMWInst
::const_op_iterator AtomicRMWInst::op_begin() const { return OperandTraits
<AtomicRMWInst>::op_begin(const_cast<AtomicRMWInst*>
(this)); } AtomicRMWInst::op_iterator AtomicRMWInst::op_end()
{ return OperandTraits<AtomicRMWInst>::op_end(this); }
AtomicRMWInst::const_op_iterator AtomicRMWInst::op_end() const
{ return OperandTraits<AtomicRMWInst>::op_end(const_cast
<AtomicRMWInst*>(this)); } Value *AtomicRMWInst::getOperand
(unsigned i_nocapture) const { (static_cast <bool> (i_nocapture
< OperandTraits<AtomicRMWInst>::operands(this) &&
"getOperand() out of range!") ? void (0) : __assert_fail ("i_nocapture < OperandTraits<AtomicRMWInst>::operands(this) && \"getOperand() out of range!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 820, __extension__ __PRETTY_FUNCTION__)); return cast_or_null
<Value>( OperandTraits<AtomicRMWInst>::op_begin(const_cast
<AtomicRMWInst*>(this))[i_nocapture].get()); } void AtomicRMWInst
::setOperand(unsigned i_nocapture, Value *Val_nocapture) { (static_cast
<bool> (i_nocapture < OperandTraits<AtomicRMWInst
>::operands(this) && "setOperand() out of range!")
? void (0) : __assert_fail ("i_nocapture < OperandTraits<AtomicRMWInst>::operands(this) && \"setOperand() out of range!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 820, __extension__ __PRETTY_FUNCTION__)); OperandTraits<
AtomicRMWInst>::op_begin(this)[i_nocapture] = Val_nocapture
; } unsigned AtomicRMWInst::getNumOperands() const { return OperandTraits
<AtomicRMWInst>::operands(this); } template <int Idx_nocapture
> Use &AtomicRMWInst::Op() { return this->OpFrom<
Idx_nocapture>(this); } template <int Idx_nocapture>
const Use &AtomicRMWInst::Op() const { return this->OpFrom
<Idx_nocapture>(this); }
821
822//===----------------------------------------------------------------------===//
823// GetElementPtrInst Class
824//===----------------------------------------------------------------------===//
825
826// checkGEPType - Simple wrapper function to give a better assertion failure
827// message on bad indexes for a gep instruction.
828//
829inline Type *checkGEPType(Type *Ty) {
830 assert(Ty && "Invalid GetElementPtrInst indices for type!")(static_cast <bool> (Ty && "Invalid GetElementPtrInst indices for type!"
) ? void (0) : __assert_fail ("Ty && \"Invalid GetElementPtrInst indices for type!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 830, __extension__ __PRETTY_FUNCTION__))
;
831 return Ty;
832}
833
834/// an instruction for type-safe pointer arithmetic to
835/// access elements of arrays and structs
836///
837class GetElementPtrInst : public Instruction {
838 Type *SourceElementType;
839 Type *ResultElementType;
840
841 GetElementPtrInst(const GetElementPtrInst &GEPI);
842
843 /// Constructors - Create a getelementptr instruction with a base pointer an
844 /// list of indices. The first ctor can optionally insert before an existing
845 /// instruction, the second appends the new instruction to the specified
846 /// BasicBlock.
847 inline GetElementPtrInst(Type *PointeeType, Value *Ptr,
848 ArrayRef<Value *> IdxList, unsigned Values,
849 const Twine &NameStr, Instruction *InsertBefore);
850 inline GetElementPtrInst(Type *PointeeType, Value *Ptr,
851 ArrayRef<Value *> IdxList, unsigned Values,
852 const Twine &NameStr, BasicBlock *InsertAtEnd);
853
854 void init(Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr);
855
856protected:
857 // Note: Instruction needs to be a friend here to call cloneImpl.
858 friend class Instruction;
859
860 GetElementPtrInst *cloneImpl() const;
861
862public:
863 static GetElementPtrInst *Create(Type *PointeeType, Value *Ptr,
864 ArrayRef<Value *> IdxList,
865 const Twine &NameStr = "",
866 Instruction *InsertBefore = nullptr) {
867 unsigned Values = 1 + unsigned(IdxList.size());
868 if (!PointeeType)
869 PointeeType =
870 cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
871 else
872 assert((static_cast <bool> (PointeeType == cast<PointerType
>(Ptr->getType()->getScalarType())->getElementType
()) ? void (0) : __assert_fail ("PointeeType == cast<PointerType>(Ptr->getType()->getScalarType())->getElementType()"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 874, __extension__ __PRETTY_FUNCTION__))
873 PointeeType ==(static_cast <bool> (PointeeType == cast<PointerType
>(Ptr->getType()->getScalarType())->getElementType
()) ? void (0) : __assert_fail ("PointeeType == cast<PointerType>(Ptr->getType()->getScalarType())->getElementType()"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 874, __extension__ __PRETTY_FUNCTION__))
874 cast<PointerType>(Ptr->getType()->getScalarType())->getElementType())(static_cast <bool> (PointeeType == cast<PointerType
>(Ptr->getType()->getScalarType())->getElementType
()) ? void (0) : __assert_fail ("PointeeType == cast<PointerType>(Ptr->getType()->getScalarType())->getElementType()"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 874, __extension__ __PRETTY_FUNCTION__))
;
875 return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
876 NameStr, InsertBefore);
877 }
878
879 static GetElementPtrInst *Create(Type *PointeeType, Value *Ptr,
880 ArrayRef<Value *> IdxList,
881 const Twine &NameStr,
882 BasicBlock *InsertAtEnd) {
883 unsigned Values = 1 + unsigned(IdxList.size());
884 if (!PointeeType)
885 PointeeType =
886 cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
887 else
888 assert((static_cast <bool> (PointeeType == cast<PointerType
>(Ptr->getType()->getScalarType())->getElementType
()) ? void (0) : __assert_fail ("PointeeType == cast<PointerType>(Ptr->getType()->getScalarType())->getElementType()"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 890, __extension__ __PRETTY_FUNCTION__))
889 PointeeType ==(static_cast <bool> (PointeeType == cast<PointerType
>(Ptr->getType()->getScalarType())->getElementType
()) ? void (0) : __assert_fail ("PointeeType == cast<PointerType>(Ptr->getType()->getScalarType())->getElementType()"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 890, __extension__ __PRETTY_FUNCTION__))
890 cast<PointerType>(Ptr->getType()->getScalarType())->getElementType())(static_cast <bool> (PointeeType == cast<PointerType
>(Ptr->getType()->getScalarType())->getElementType
()) ? void (0) : __assert_fail ("PointeeType == cast<PointerType>(Ptr->getType()->getScalarType())->getElementType()"
, "/build/llvm-toolchain-snapshot-7~svn329677/include/llvm/IR/Instructions.h"
, 890, __extension__ __PRETTY_FUNCTION__))
;
891 return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
892 NameStr, InsertAtEnd);
893 }
894
895 /// Create an "inbounds" getelementptr. See the documentation for the
896 /// "inbounds" flag in LangRef.html for details.
897 static GetElementPtrInst *CreateInBounds(Value *Ptr,
898 ArrayRef<Value *> IdxList,
899 const Twine &NameStr = "",
900 Instruction *InsertBefore = nullptr){
901 return CreateInBounds(nullptr, Ptr, IdxList, NameStr, InsertBefore);
902 }
903
904 static GetElementPtrInst *
905 CreateInBounds(Type *PointeeType, Value *Ptr, ArrayRef<Value *> IdxList,
906 const Twine &NameStr = "",
907 Instruction *InsertBefore = nullptr) {
908 GetElementPtrInst *GEP =
909 Create(PointeeType, Ptr, IdxList, NameStr, InsertBefore);
910 GEP->setIsInBounds(true);
911 return GEP;
912 }
913
914 static GetElementPtrInst *CreateInBounds(Value *Ptr,
915 ArrayRef<Value *> IdxList,
916 const Twine &NameStr,
917 BasicBlock *InsertAtEnd) {
918 return CreateInBounds(nullptr, Ptr, IdxList, NameStr, InsertAtEnd);
919 }
920
921 static GetElementPtrInst *CreateInBounds(Type *PointeeType, Value *Ptr,