Bug Summary

File:build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/lib/Analysis/ConstantFolding.cpp
Warning:line 675, column 39
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name ConstantFolding.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm -resource-dir /usr/lib/llvm-15/lib/clang/15.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I lib/Analysis -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/lib/Analysis -I include -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-04-20-140412-16051-1 -x c++ /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/lib/Analysis/ConstantFolding.cpp
1//===-- ConstantFolding.cpp - Fold instructions into constants ------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines routines for folding instructions into constants.
10//
11// Also, to supplement the basic IR ConstantExpr simplifications,
12// this file defines some additional folding routines that can make use of
13// DataLayout information. These functions cannot go in IR due to library
14// dependency issues.
15//
16//===----------------------------------------------------------------------===//
17
18#include "llvm/Analysis/ConstantFolding.h"
19#include "llvm/ADT/APFloat.h"
20#include "llvm/ADT/APInt.h"
21#include "llvm/ADT/APSInt.h"
22#include "llvm/ADT/ArrayRef.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
25#include "llvm/ADT/SmallVector.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/Analysis/TargetFolder.h"
28#include "llvm/Analysis/TargetLibraryInfo.h"
29#include "llvm/Analysis/ValueTracking.h"
30#include "llvm/Analysis/VectorUtils.h"
31#include "llvm/Config/config.h"
32#include "llvm/IR/Constant.h"
33#include "llvm/IR/Constants.h"
34#include "llvm/IR/DataLayout.h"
35#include "llvm/IR/DerivedTypes.h"
36#include "llvm/IR/Function.h"
37#include "llvm/IR/GlobalValue.h"
38#include "llvm/IR/GlobalVariable.h"
39#include "llvm/IR/InstrTypes.h"
40#include "llvm/IR/Instruction.h"
41#include "llvm/IR/Instructions.h"
42#include "llvm/IR/IntrinsicInst.h"
43#include "llvm/IR/Intrinsics.h"
44#include "llvm/IR/IntrinsicsAArch64.h"
45#include "llvm/IR/IntrinsicsAMDGPU.h"
46#include "llvm/IR/IntrinsicsARM.h"
47#include "llvm/IR/IntrinsicsWebAssembly.h"
48#include "llvm/IR/IntrinsicsX86.h"
49#include "llvm/IR/Operator.h"
50#include "llvm/IR/Type.h"
51#include "llvm/IR/Value.h"
52#include "llvm/Support/Casting.h"
53#include "llvm/Support/ErrorHandling.h"
54#include "llvm/Support/KnownBits.h"
55#include "llvm/Support/MathExtras.h"
56#include <cassert>
57#include <cerrno>
58#include <cfenv>
59#include <cmath>
60#include <cstdint>
61
62using namespace llvm;
63
64namespace {
65
66//===----------------------------------------------------------------------===//
67// Constant Folding internal helper functions
68//===----------------------------------------------------------------------===//
69
70static Constant *foldConstVectorToAPInt(APInt &Result, Type *DestTy,
71 Constant *C, Type *SrcEltTy,
72 unsigned NumSrcElts,
73 const DataLayout &DL) {
74 // Now that we know that the input value is a vector of integers, just shift
75 // and insert them into our result.
76 unsigned BitShift = DL.getTypeSizeInBits(SrcEltTy);
77 for (unsigned i = 0; i != NumSrcElts; ++i) {
78 Constant *Element;
79 if (DL.isLittleEndian())
80 Element = C->getAggregateElement(NumSrcElts - i - 1);
81 else
82 Element = C->getAggregateElement(i);
83
84 if (Element && isa<UndefValue>(Element)) {
85 Result <<= BitShift;
86 continue;
87 }
88
89 auto *ElementCI = dyn_cast_or_null<ConstantInt>(Element);
90 if (!ElementCI)
91 return ConstantExpr::getBitCast(C, DestTy);
92
93 Result <<= BitShift;
94 Result |= ElementCI->getValue().zextOrSelf(Result.getBitWidth());
95 }
96
97 return nullptr;
98}
99
100/// Constant fold bitcast, symbolically evaluating it with DataLayout.
101/// This always returns a non-null constant, but it may be a
102/// ConstantExpr if unfoldable.
103Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
104 assert(CastInst::castIsValid(Instruction::BitCast, C, DestTy) &&(static_cast <bool> (CastInst::castIsValid(Instruction::
BitCast, C, DestTy) && "Invalid constantexpr bitcast!"
) ? void (0) : __assert_fail ("CastInst::castIsValid(Instruction::BitCast, C, DestTy) && \"Invalid constantexpr bitcast!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 105, __extension__
__PRETTY_FUNCTION__))
105 "Invalid constantexpr bitcast!")(static_cast <bool> (CastInst::castIsValid(Instruction::
BitCast, C, DestTy) && "Invalid constantexpr bitcast!"
) ? void (0) : __assert_fail ("CastInst::castIsValid(Instruction::BitCast, C, DestTy) && \"Invalid constantexpr bitcast!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 105, __extension__
__PRETTY_FUNCTION__))
;
106
107 // Catch the obvious splat cases.
108 if (Constant *Res = ConstantFoldLoadFromUniformValue(C, DestTy))
109 return Res;
110
111 if (auto *VTy = dyn_cast<VectorType>(C->getType())) {
112 // Handle a vector->scalar integer/fp cast.
113 if (isa<IntegerType>(DestTy) || DestTy->isFloatingPointTy()) {
114 unsigned NumSrcElts = cast<FixedVectorType>(VTy)->getNumElements();
115 Type *SrcEltTy = VTy->getElementType();
116
117 // If the vector is a vector of floating point, convert it to vector of int
118 // to simplify things.
119 if (SrcEltTy->isFloatingPointTy()) {
120 unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
121 auto *SrcIVTy = FixedVectorType::get(
122 IntegerType::get(C->getContext(), FPWidth), NumSrcElts);
123 // Ask IR to do the conversion now that #elts line up.
124 C = ConstantExpr::getBitCast(C, SrcIVTy);
125 }
126
127 APInt Result(DL.getTypeSizeInBits(DestTy), 0);
128 if (Constant *CE = foldConstVectorToAPInt(Result, DestTy, C,
129 SrcEltTy, NumSrcElts, DL))
130 return CE;
131
132 if (isa<IntegerType>(DestTy))
133 return ConstantInt::get(DestTy, Result);
134
135 APFloat FP(DestTy->getFltSemantics(), Result);
136 return ConstantFP::get(DestTy->getContext(), FP);
137 }
138 }
139
140 // The code below only handles casts to vectors currently.
141 auto *DestVTy = dyn_cast<VectorType>(DestTy);
142 if (!DestVTy)
143 return ConstantExpr::getBitCast(C, DestTy);
144
145 // If this is a scalar -> vector cast, convert the input into a <1 x scalar>
146 // vector so the code below can handle it uniformly.
147 if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
148 Constant *Ops = C; // don't take the address of C!
149 return FoldBitCast(ConstantVector::get(Ops), DestTy, DL);
150 }
151
152 // If this is a bitcast from constant vector -> vector, fold it.
153 if (!isa<ConstantDataVector>(C) && !isa<ConstantVector>(C))
154 return ConstantExpr::getBitCast(C, DestTy);
155
156 // If the element types match, IR can fold it.
157 unsigned NumDstElt = cast<FixedVectorType>(DestVTy)->getNumElements();
158 unsigned NumSrcElt = cast<FixedVectorType>(C->getType())->getNumElements();
159 if (NumDstElt == NumSrcElt)
160 return ConstantExpr::getBitCast(C, DestTy);
161
162 Type *SrcEltTy = cast<VectorType>(C->getType())->getElementType();
163 Type *DstEltTy = DestVTy->getElementType();
164
165 // Otherwise, we're changing the number of elements in a vector, which
166 // requires endianness information to do the right thing. For example,
167 // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
168 // folds to (little endian):
169 // <4 x i32> <i32 0, i32 0, i32 1, i32 0>
170 // and to (big endian):
171 // <4 x i32> <i32 0, i32 0, i32 0, i32 1>
172
173 // First thing is first. We only want to think about integer here, so if
174 // we have something in FP form, recast it as integer.
175 if (DstEltTy->isFloatingPointTy()) {
176 // Fold to an vector of integers with same size as our FP type.
177 unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits();
178 auto *DestIVTy = FixedVectorType::get(
179 IntegerType::get(C->getContext(), FPWidth), NumDstElt);
180 // Recursively handle this integer conversion, if possible.
181 C = FoldBitCast(C, DestIVTy, DL);
182
183 // Finally, IR can handle this now that #elts line up.
184 return ConstantExpr::getBitCast(C, DestTy);
185 }
186
187 // Okay, we know the destination is integer, if the input is FP, convert
188 // it to integer first.
189 if (SrcEltTy->isFloatingPointTy()) {
190 unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
191 auto *SrcIVTy = FixedVectorType::get(
192 IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
193 // Ask IR to do the conversion now that #elts line up.
194 C = ConstantExpr::getBitCast(C, SrcIVTy);
195 // If IR wasn't able to fold it, bail out.
196 if (!isa<ConstantVector>(C) && // FIXME: Remove ConstantVector.
197 !isa<ConstantDataVector>(C))
198 return C;
199 }
200
201 // Now we know that the input and output vectors are both integer vectors
202 // of the same size, and that their #elements is not the same. Do the
203 // conversion here, which depends on whether the input or output has
204 // more elements.
205 bool isLittleEndian = DL.isLittleEndian();
206
207 SmallVector<Constant*, 32> Result;
208 if (NumDstElt < NumSrcElt) {
209 // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
210 Constant *Zero = Constant::getNullValue(DstEltTy);
211 unsigned Ratio = NumSrcElt/NumDstElt;
212 unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits();
213 unsigned SrcElt = 0;
214 for (unsigned i = 0; i != NumDstElt; ++i) {
215 // Build each element of the result.
216 Constant *Elt = Zero;
217 unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
218 for (unsigned j = 0; j != Ratio; ++j) {
219 Constant *Src = C->getAggregateElement(SrcElt++);
220 if (Src && isa<UndefValue>(Src))
221 Src = Constant::getNullValue(
222 cast<VectorType>(C->getType())->getElementType());
223 else
224 Src = dyn_cast_or_null<ConstantInt>(Src);
225 if (!Src) // Reject constantexpr elements.
226 return ConstantExpr::getBitCast(C, DestTy);
227
228 // Zero extend the element to the right size.
229 Src = ConstantExpr::getZExt(Src, Elt->getType());
230
231 // Shift it to the right place, depending on endianness.
232 Src = ConstantExpr::getShl(Src,
233 ConstantInt::get(Src->getType(), ShiftAmt));
234 ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
235
236 // Mix it in.
237 Elt = ConstantExpr::getOr(Elt, Src);
238 }
239 Result.push_back(Elt);
240 }
241 return ConstantVector::get(Result);
242 }
243
244 // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
245 unsigned Ratio = NumDstElt/NumSrcElt;
246 unsigned DstBitSize = DL.getTypeSizeInBits(DstEltTy);
247
248 // Loop over each source value, expanding into multiple results.
249 for (unsigned i = 0; i != NumSrcElt; ++i) {
250 auto *Element = C->getAggregateElement(i);
251
252 if (!Element) // Reject constantexpr elements.
253 return ConstantExpr::getBitCast(C, DestTy);
254
255 if (isa<UndefValue>(Element)) {
256 // Correctly Propagate undef values.
257 Result.append(Ratio, UndefValue::get(DstEltTy));
258 continue;
259 }
260
261 auto *Src = dyn_cast<ConstantInt>(Element);
262 if (!Src)
263 return ConstantExpr::getBitCast(C, DestTy);
264
265 unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
266 for (unsigned j = 0; j != Ratio; ++j) {
267 // Shift the piece of the value into the right place, depending on
268 // endianness.
269 Constant *Elt = ConstantExpr::getLShr(Src,
270 ConstantInt::get(Src->getType(), ShiftAmt));
271 ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
272
273 // Truncate the element to an integer with the same pointer size and
274 // convert the element back to a pointer using a inttoptr.
275 if (DstEltTy->isPointerTy()) {
276 IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize);
277 Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy);
278 Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy));
279 continue;
280 }
281
282 // Truncate and remember this piece.
283 Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
284 }
285 }
286
287 return ConstantVector::get(Result);
288}
289
290} // end anonymous namespace
291
292/// If this constant is a constant offset from a global, return the global and
293/// the constant. Because of constantexprs, this function is recursive.
294bool llvm::IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
295 APInt &Offset, const DataLayout &DL,
296 DSOLocalEquivalent **DSOEquiv) {
297 if (DSOEquiv)
298 *DSOEquiv = nullptr;
299
300 // Trivial case, constant is the global.
301 if ((GV = dyn_cast<GlobalValue>(C))) {
302 unsigned BitWidth = DL.getIndexTypeSizeInBits(GV->getType());
303 Offset = APInt(BitWidth, 0);
304 return true;
305 }
306
307 if (auto *FoundDSOEquiv = dyn_cast<DSOLocalEquivalent>(C)) {
308 if (DSOEquiv)
309 *DSOEquiv = FoundDSOEquiv;
310 GV = FoundDSOEquiv->getGlobalValue();
311 unsigned BitWidth = DL.getIndexTypeSizeInBits(GV->getType());
312 Offset = APInt(BitWidth, 0);
313 return true;
314 }
315
316 // Otherwise, if this isn't a constant expr, bail out.
317 auto *CE = dyn_cast<ConstantExpr>(C);
318 if (!CE) return false;
319
320 // Look through ptr->int and ptr->ptr casts.
321 if (CE->getOpcode() == Instruction::PtrToInt ||
322 CE->getOpcode() == Instruction::BitCast)
323 return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, DL,
324 DSOEquiv);
325
326 // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
327 auto *GEP = dyn_cast<GEPOperator>(CE);
328 if (!GEP)
329 return false;
330
331 unsigned BitWidth = DL.getIndexTypeSizeInBits(GEP->getType());
332 APInt TmpOffset(BitWidth, 0);
333
334 // If the base isn't a global+constant, we aren't either.
335 if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, DL,
336 DSOEquiv))
337 return false;
338
339 // Otherwise, add any offset that our operands provide.
340 if (!GEP->accumulateConstantOffset(DL, TmpOffset))
341 return false;
342
343 Offset = TmpOffset;
344 return true;
345}
346
347Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy,
348 const DataLayout &DL) {
349 do {
350 Type *SrcTy = C->getType();
351 if (SrcTy == DestTy)
352 return C;
353
354 TypeSize DestSize = DL.getTypeSizeInBits(DestTy);
355 TypeSize SrcSize = DL.getTypeSizeInBits(SrcTy);
356 if (!TypeSize::isKnownGE(SrcSize, DestSize))
357 return nullptr;
358
359 // Catch the obvious splat cases (since all-zeros can coerce non-integral
360 // pointers legally).
361 if (Constant *Res = ConstantFoldLoadFromUniformValue(C, DestTy))
362 return Res;
363
364 // If the type sizes are the same and a cast is legal, just directly
365 // cast the constant.
366 // But be careful not to coerce non-integral pointers illegally.
367 if (SrcSize == DestSize &&
368 DL.isNonIntegralPointerType(SrcTy->getScalarType()) ==
369 DL.isNonIntegralPointerType(DestTy->getScalarType())) {
370 Instruction::CastOps Cast = Instruction::BitCast;
371 // If we are going from a pointer to int or vice versa, we spell the cast
372 // differently.
373 if (SrcTy->isIntegerTy() && DestTy->isPointerTy())
374 Cast = Instruction::IntToPtr;
375 else if (SrcTy->isPointerTy() && DestTy->isIntegerTy())
376 Cast = Instruction::PtrToInt;
377
378 if (CastInst::castIsValid(Cast, C, DestTy))
379 return ConstantExpr::getCast(Cast, C, DestTy);
380 }
381
382 // If this isn't an aggregate type, there is nothing we can do to drill down
383 // and find a bitcastable constant.
384 if (!SrcTy->isAggregateType() && !SrcTy->isVectorTy())
385 return nullptr;
386
387 // We're simulating a load through a pointer that was bitcast to point to
388 // a different type, so we can try to walk down through the initial
389 // elements of an aggregate to see if some part of the aggregate is
390 // castable to implement the "load" semantic model.
391 if (SrcTy->isStructTy()) {
392 // Struct types might have leading zero-length elements like [0 x i32],
393 // which are certainly not what we are looking for, so skip them.
394 unsigned Elem = 0;
395 Constant *ElemC;
396 do {
397 ElemC = C->getAggregateElement(Elem++);
398 } while (ElemC && DL.getTypeSizeInBits(ElemC->getType()).isZero());
399 C = ElemC;
400 } else {
401 // For non-byte-sized vector elements, the first element is not
402 // necessarily located at the vector base address.
403 if (auto *VT = dyn_cast<VectorType>(SrcTy))
404 if (!DL.typeSizeEqualsStoreSize(VT->getElementType()))
405 return nullptr;
406
407 C = C->getAggregateElement(0u);
408 }
409 } while (C);
410
411 return nullptr;
412}
413
414namespace {
415
416/// Recursive helper to read bits out of global. C is the constant being copied
417/// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy
418/// results into and BytesLeft is the number of bytes left in
419/// the CurPtr buffer. DL is the DataLayout.
420bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr,
421 unsigned BytesLeft, const DataLayout &DL) {
422 assert(ByteOffset <= DL.getTypeAllocSize(C->getType()) &&(static_cast <bool> (ByteOffset <= DL.getTypeAllocSize
(C->getType()) && "Out of range access") ? void (0
) : __assert_fail ("ByteOffset <= DL.getTypeAllocSize(C->getType()) && \"Out of range access\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 423, __extension__
__PRETTY_FUNCTION__))
423 "Out of range access")(static_cast <bool> (ByteOffset <= DL.getTypeAllocSize
(C->getType()) && "Out of range access") ? void (0
) : __assert_fail ("ByteOffset <= DL.getTypeAllocSize(C->getType()) && \"Out of range access\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 423, __extension__
__PRETTY_FUNCTION__))
;
424
425 // If this element is zero or undefined, we can just return since *CurPtr is
426 // zero initialized.
427 if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
428 return true;
429
430 if (auto *CI = dyn_cast<ConstantInt>(C)) {
431 if (CI->getBitWidth() > 64 ||
432 (CI->getBitWidth() & 7) != 0)
433 return false;
434
435 uint64_t Val = CI->getZExtValue();
436 unsigned IntBytes = unsigned(CI->getBitWidth()/8);
437
438 for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
439 int n = ByteOffset;
440 if (!DL.isLittleEndian())
441 n = IntBytes - n - 1;
442 CurPtr[i] = (unsigned char)(Val >> (n * 8));
443 ++ByteOffset;
444 }
445 return true;
446 }
447
448 if (auto *CFP = dyn_cast<ConstantFP>(C)) {
449 if (CFP->getType()->isDoubleTy()) {
450 C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), DL);
451 return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
452 }
453 if (CFP->getType()->isFloatTy()){
454 C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), DL);
455 return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
456 }
457 if (CFP->getType()->isHalfTy()){
458 C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), DL);
459 return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
460 }
461 return false;
462 }
463
464 if (auto *CS = dyn_cast<ConstantStruct>(C)) {
465 const StructLayout *SL = DL.getStructLayout(CS->getType());
466 unsigned Index = SL->getElementContainingOffset(ByteOffset);
467 uint64_t CurEltOffset = SL->getElementOffset(Index);
468 ByteOffset -= CurEltOffset;
469
470 while (true) {
471 // If the element access is to the element itself and not to tail padding,
472 // read the bytes from the element.
473 uint64_t EltSize = DL.getTypeAllocSize(CS->getOperand(Index)->getType());
474
475 if (ByteOffset < EltSize &&
476 !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
477 BytesLeft, DL))
478 return false;
479
480 ++Index;
481
482 // Check to see if we read from the last struct element, if so we're done.
483 if (Index == CS->getType()->getNumElements())
484 return true;
485
486 // If we read all of the bytes we needed from this element we're done.
487 uint64_t NextEltOffset = SL->getElementOffset(Index);
488
489 if (BytesLeft <= NextEltOffset - CurEltOffset - ByteOffset)
490 return true;
491
492 // Move to the next element of the struct.
493 CurPtr += NextEltOffset - CurEltOffset - ByteOffset;
494 BytesLeft -= NextEltOffset - CurEltOffset - ByteOffset;
495 ByteOffset = 0;
496 CurEltOffset = NextEltOffset;
497 }
498 // not reached.
499 }
500
501 if (isa<ConstantArray>(C) || isa<ConstantVector>(C) ||
502 isa<ConstantDataSequential>(C)) {
503 uint64_t NumElts;
504 Type *EltTy;
505 if (auto *AT = dyn_cast<ArrayType>(C->getType())) {
506 NumElts = AT->getNumElements();
507 EltTy = AT->getElementType();
508 } else {
509 NumElts = cast<FixedVectorType>(C->getType())->getNumElements();
510 EltTy = cast<FixedVectorType>(C->getType())->getElementType();
511 }
512 uint64_t EltSize = DL.getTypeAllocSize(EltTy);
513 uint64_t Index = ByteOffset / EltSize;
514 uint64_t Offset = ByteOffset - Index * EltSize;
515
516 for (; Index != NumElts; ++Index) {
517 if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr,
518 BytesLeft, DL))
519 return false;
520
521 uint64_t BytesWritten = EltSize - Offset;
522 assert(BytesWritten <= EltSize && "Not indexing into this element?")(static_cast <bool> (BytesWritten <= EltSize &&
"Not indexing into this element?") ? void (0) : __assert_fail
("BytesWritten <= EltSize && \"Not indexing into this element?\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 522, __extension__
__PRETTY_FUNCTION__))
;
523 if (BytesWritten >= BytesLeft)
524 return true;
525
526 Offset = 0;
527 BytesLeft -= BytesWritten;
528 CurPtr += BytesWritten;
529 }
530 return true;
531 }
532
533 if (auto *CE = dyn_cast<ConstantExpr>(C)) {
534 if (CE->getOpcode() == Instruction::IntToPtr &&
535 CE->getOperand(0)->getType() == DL.getIntPtrType(CE->getType())) {
536 return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
537 BytesLeft, DL);
538 }
539 }
540
541 // Otherwise, unknown initializer type.
542 return false;
543}
544
545Constant *FoldReinterpretLoadFromConst(Constant *C, Type *LoadTy,
546 int64_t Offset, const DataLayout &DL) {
547 // Bail out early. Not expect to load from scalable global variable.
548 if (isa<ScalableVectorType>(LoadTy))
549 return nullptr;
550
551 auto *IntType = dyn_cast<IntegerType>(LoadTy);
552
553 // If this isn't an integer load we can't fold it directly.
554 if (!IntType) {
555 // If this is a non-integer load, we can try folding it as an int load and
556 // then bitcast the result. This can be useful for union cases. Note
557 // that address spaces don't matter here since we're not going to result in
558 // an actual new load.
559 if (!LoadTy->isFloatingPointTy() && !LoadTy->isPointerTy() &&
560 !LoadTy->isVectorTy())
561 return nullptr;
562
563 Type *MapTy = Type::getIntNTy(
564 C->getContext(), DL.getTypeSizeInBits(LoadTy).getFixedSize());
565 if (Constant *Res = FoldReinterpretLoadFromConst(C, MapTy, Offset, DL)) {
566 if (Res->isNullValue() && !LoadTy->isX86_MMXTy() &&
567 !LoadTy->isX86_AMXTy())
568 // Materializing a zero can be done trivially without a bitcast
569 return Constant::getNullValue(LoadTy);
570 Type *CastTy = LoadTy->isPtrOrPtrVectorTy() ? DL.getIntPtrType(LoadTy) : LoadTy;
571 Res = FoldBitCast(Res, CastTy, DL);
572 if (LoadTy->isPtrOrPtrVectorTy()) {
573 // For vector of pointer, we needed to first convert to a vector of integer, then do vector inttoptr
574 if (Res->isNullValue() && !LoadTy->isX86_MMXTy() &&
575 !LoadTy->isX86_AMXTy())
576 return Constant::getNullValue(LoadTy);
577 if (DL.isNonIntegralPointerType(LoadTy->getScalarType()))
578 // Be careful not to replace a load of an addrspace value with an inttoptr here
579 return nullptr;
580 Res = ConstantExpr::getCast(Instruction::IntToPtr, Res, LoadTy);
581 }
582 return Res;
583 }
584 return nullptr;
585 }
586
587 unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
588 if (BytesLoaded > 32 || BytesLoaded == 0)
589 return nullptr;
590
591 // If we're not accessing anything in this constant, the result is undefined.
592 if (Offset <= -1 * static_cast<int64_t>(BytesLoaded))
593 return UndefValue::get(IntType);
594
595 // TODO: We should be able to support scalable types.
596 TypeSize InitializerSize = DL.getTypeAllocSize(C->getType());
597 if (InitializerSize.isScalable())
598 return nullptr;
599
600 // If we're not accessing anything in this constant, the result is undefined.
601 if (Offset >= (int64_t)InitializerSize.getFixedValue())
602 return UndefValue::get(IntType);
603
604 unsigned char RawBytes[32] = {0};
605 unsigned char *CurPtr = RawBytes;
606 unsigned BytesLeft = BytesLoaded;
607
608 // If we're loading off the beginning of the global, some bytes may be valid.
609 if (Offset < 0) {
610 CurPtr += -Offset;
611 BytesLeft += Offset;
612 Offset = 0;
613 }
614
615 if (!ReadDataFromGlobal(C, Offset, CurPtr, BytesLeft, DL))
616 return nullptr;
617
618 APInt ResultVal = APInt(IntType->getBitWidth(), 0);
619 if (DL.isLittleEndian()) {
620 ResultVal = RawBytes[BytesLoaded - 1];
621 for (unsigned i = 1; i != BytesLoaded; ++i) {
622 ResultVal <<= 8;
623 ResultVal |= RawBytes[BytesLoaded - 1 - i];
624 }
625 } else {
626 ResultVal = RawBytes[0];
627 for (unsigned i = 1; i != BytesLoaded; ++i) {
628 ResultVal <<= 8;
629 ResultVal |= RawBytes[i];
630 }
631 }
632
633 return ConstantInt::get(IntType->getContext(), ResultVal);
634}
635
636/// If this Offset points exactly to the start of an aggregate element, return
637/// that element, otherwise return nullptr.
638Constant *getConstantAtOffset(Constant *Base, APInt Offset,
639 const DataLayout &DL) {
640 if (Offset.isZero())
4
Taking true branch
641 return Base;
5
Returning pointer (loaded from 'Base'), which participates in a condition later
642
643 if (!isa<ConstantAggregate>(Base) && !isa<ConstantDataSequential>(Base))
644 return nullptr;
645
646 Type *ElemTy = Base->getType();
647 SmallVector<APInt> Indices = DL.getGEPIndicesForOffset(ElemTy, Offset);
648 if (!Offset.isZero() || !Indices[0].isZero())
649 return nullptr;
650
651 Constant *C = Base;
652 for (const APInt &Index : drop_begin(Indices)) {
653 if (Index.isNegative() || Index.getActiveBits() >= 32)
654 return nullptr;
655
656 C = C->getAggregateElement(Index.getZExtValue());
657 if (!C)
658 return nullptr;
659 }
660
661 return C;
662}
663
664} // end anonymous namespace
665
666Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty,
667 const APInt &Offset,
668 const DataLayout &DL) {
669 if (Constant *AtOffset = getConstantAtOffset(C, Offset, DL))
3
Calling 'getConstantAtOffset'
6
Returning from 'getConstantAtOffset'
7
Assuming 'AtOffset' is null
8
Taking false branch
670 if (Constant *Result = ConstantFoldLoadThroughBitcast(AtOffset, Ty, DL))
671 return Result;
672
673 // Explicitly check for out-of-bounds access, so we return undef even if the
674 // constant is a uniform value.
675 TypeSize Size = DL.getTypeAllocSize(C->getType());
9
Called C++ object pointer is null
676 if (!Size.isScalable() && Offset.sge(Size.getFixedSize()))
677 return UndefValue::get(Ty);
678
679 // Try an offset-independent fold of a uniform value.
680 if (Constant *Result = ConstantFoldLoadFromUniformValue(C, Ty))
681 return Result;
682
683 // Try hard to fold loads from bitcasted strange and non-type-safe things.
684 if (Offset.getMinSignedBits() <= 64)
685 if (Constant *Result =
686 FoldReinterpretLoadFromConst(C, Ty, Offset.getSExtValue(), DL))
687 return Result;
688
689 return nullptr;
690}
691
692Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty,
693 const DataLayout &DL) {
694 return ConstantFoldLoadFromConst(C, Ty, APInt(64, 0), DL);
1
Passing value via 1st parameter 'C'
2
Calling 'ConstantFoldLoadFromConst'
695}
696
697Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty,
698 APInt Offset,
699 const DataLayout &DL) {
700 C = cast<Constant>(C->stripAndAccumulateConstantOffsets(
701 DL, Offset, /* AllowNonInbounds */ true));
702
703 if (auto *GV = dyn_cast<GlobalVariable>(C))
704 if (GV->isConstant() && GV->hasDefinitiveInitializer())
705 if (Constant *Result = ConstantFoldLoadFromConst(GV->getInitializer(), Ty,
706 Offset, DL))
707 return Result;
708
709 // If this load comes from anywhere in a uniform constant global, the value
710 // is always the same, regardless of the loaded offset.
711 if (auto *GV = dyn_cast<GlobalVariable>(getUnderlyingObject(C))) {
712 if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
713 if (Constant *Res =
714 ConstantFoldLoadFromUniformValue(GV->getInitializer(), Ty))
715 return Res;
716 }
717 }
718
719 return nullptr;
720}
721
722Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty,
723 const DataLayout &DL) {
724 APInt Offset(DL.getIndexTypeSizeInBits(C->getType()), 0);
725 return ConstantFoldLoadFromConstPtr(C, Ty, Offset, DL);
726}
727
728Constant *llvm::ConstantFoldLoadFromUniformValue(Constant *C, Type *Ty) {
729 if (isa<PoisonValue>(C))
730 return PoisonValue::get(Ty);
731 if (isa<UndefValue>(C))
732 return UndefValue::get(Ty);
733 if (C->isNullValue() && !Ty->isX86_MMXTy() && !Ty->isX86_AMXTy())
734 return Constant::getNullValue(Ty);
735 if (C->isAllOnesValue() &&
736 (Ty->isIntOrIntVectorTy() || Ty->isFPOrFPVectorTy()))
737 return Constant::getAllOnesValue(Ty);
738 return nullptr;
739}
740
741namespace {
742
743/// One of Op0/Op1 is a constant expression.
744/// Attempt to symbolically evaluate the result of a binary operator merging
745/// these together. If target data info is available, it is provided as DL,
746/// otherwise DL is null.
747Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, Constant *Op1,
748 const DataLayout &DL) {
749 // SROA
750
751 // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
752 // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
753 // bits.
754
755 if (Opc == Instruction::And) {
756 KnownBits Known0 = computeKnownBits(Op0, DL);
757 KnownBits Known1 = computeKnownBits(Op1, DL);
758 if ((Known1.One | Known0.Zero).isAllOnes()) {
759 // All the bits of Op0 that the 'and' could be masking are already zero.
760 return Op0;
761 }
762 if ((Known0.One | Known1.Zero).isAllOnes()) {
763 // All the bits of Op1 that the 'and' could be masking are already zero.
764 return Op1;
765 }
766
767 Known0 &= Known1;
768 if (Known0.isConstant())
769 return ConstantInt::get(Op0->getType(), Known0.getConstant());
770 }
771
772 // If the constant expr is something like &A[123] - &A[4].f, fold this into a
773 // constant. This happens frequently when iterating over a global array.
774 if (Opc == Instruction::Sub) {
775 GlobalValue *GV1, *GV2;
776 APInt Offs1, Offs2;
777
778 if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, DL))
779 if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, DL) && GV1 == GV2) {
780 unsigned OpSize = DL.getTypeSizeInBits(Op0->getType());
781
782 // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
783 // PtrToInt may change the bitwidth so we have convert to the right size
784 // first.
785 return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) -
786 Offs2.zextOrTrunc(OpSize));
787 }
788 }
789
790 return nullptr;
791}
792
793/// If array indices are not pointer-sized integers, explicitly cast them so
794/// that they aren't implicitly casted by the getelementptr.
795Constant *CastGEPIndices(Type *SrcElemTy, ArrayRef<Constant *> Ops,
796 Type *ResultTy, Optional<unsigned> InRangeIndex,
797 const DataLayout &DL, const TargetLibraryInfo *TLI) {
798 Type *IntIdxTy = DL.getIndexType(ResultTy);
799 Type *IntIdxScalarTy = IntIdxTy->getScalarType();
800
801 bool Any = false;
802 SmallVector<Constant*, 32> NewIdxs;
803 for (unsigned i = 1, e = Ops.size(); i != e; ++i) {
804 if ((i == 1 ||
805 !isa<StructType>(GetElementPtrInst::getIndexedType(
806 SrcElemTy, Ops.slice(1, i - 1)))) &&
807 Ops[i]->getType()->getScalarType() != IntIdxScalarTy) {
808 Any = true;
809 Type *NewType = Ops[i]->getType()->isVectorTy()
810 ? IntIdxTy
811 : IntIdxScalarTy;
812 NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i],
813 true,
814 NewType,
815 true),
816 Ops[i], NewType));
817 } else
818 NewIdxs.push_back(Ops[i]);
819 }
820
821 if (!Any)
822 return nullptr;
823
824 Constant *C = ConstantExpr::getGetElementPtr(
825 SrcElemTy, Ops[0], NewIdxs, /*InBounds=*/false, InRangeIndex);
826 return ConstantFoldConstant(C, DL, TLI);
827}
828
829/// Strip the pointer casts, but preserve the address space information.
830Constant *StripPtrCastKeepAS(Constant *Ptr) {
831 assert(Ptr->getType()->isPointerTy() && "Not a pointer type")(static_cast <bool> (Ptr->getType()->isPointerTy(
) && "Not a pointer type") ? void (0) : __assert_fail
("Ptr->getType()->isPointerTy() && \"Not a pointer type\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 831, __extension__
__PRETTY_FUNCTION__))
;
832 auto *OldPtrTy = cast<PointerType>(Ptr->getType());
833 Ptr = cast<Constant>(Ptr->stripPointerCasts());
834 auto *NewPtrTy = cast<PointerType>(Ptr->getType());
835
836 // Preserve the address space number of the pointer.
837 if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) {
838 Ptr = ConstantExpr::getPointerCast(
839 Ptr, PointerType::getWithSamePointeeType(NewPtrTy,
840 OldPtrTy->getAddressSpace()));
841 }
842 return Ptr;
843}
844
845/// If we can symbolically evaluate the GEP constant expression, do so.
846Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
847 ArrayRef<Constant *> Ops,
848 const DataLayout &DL,
849 const TargetLibraryInfo *TLI) {
850 const GEPOperator *InnermostGEP = GEP;
851 bool InBounds = GEP->isInBounds();
852
853 Type *SrcElemTy = GEP->getSourceElementType();
854 Type *ResElemTy = GEP->getResultElementType();
855 Type *ResTy = GEP->getType();
856 if (!SrcElemTy->isSized() || isa<ScalableVectorType>(SrcElemTy))
857 return nullptr;
858
859 if (Constant *C = CastGEPIndices(SrcElemTy, Ops, ResTy,
860 GEP->getInRangeIndex(), DL, TLI))
861 return C;
862
863 Constant *Ptr = Ops[0];
864 if (!Ptr->getType()->isPointerTy())
865 return nullptr;
866
867 Type *IntIdxTy = DL.getIndexType(Ptr->getType());
868
869 // If this is "gep i8* Ptr, (sub 0, V)", fold this as:
870 // "inttoptr (sub (ptrtoint Ptr), V)"
871 if (Ops.size() == 2 && ResElemTy->isIntegerTy(8)) {
872 auto *CE = dyn_cast<ConstantExpr>(Ops[1]);
873 assert((!CE || CE->getType() == IntIdxTy) &&(static_cast <bool> ((!CE || CE->getType() == IntIdxTy
) && "CastGEPIndices didn't canonicalize index types!"
) ? void (0) : __assert_fail ("(!CE || CE->getType() == IntIdxTy) && \"CastGEPIndices didn't canonicalize index types!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 874, __extension__
__PRETTY_FUNCTION__))
874 "CastGEPIndices didn't canonicalize index types!")(static_cast <bool> ((!CE || CE->getType() == IntIdxTy
) && "CastGEPIndices didn't canonicalize index types!"
) ? void (0) : __assert_fail ("(!CE || CE->getType() == IntIdxTy) && \"CastGEPIndices didn't canonicalize index types!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 874, __extension__
__PRETTY_FUNCTION__))
;
875 if (CE && CE->getOpcode() == Instruction::Sub &&
876 CE->getOperand(0)->isNullValue()) {
877 Constant *Res = ConstantExpr::getPtrToInt(Ptr, CE->getType());
878 Res = ConstantExpr::getSub(Res, CE->getOperand(1));
879 Res = ConstantExpr::getIntToPtr(Res, ResTy);
880 return ConstantFoldConstant(Res, DL, TLI);
881 }
882 }
883
884 for (unsigned i = 1, e = Ops.size(); i != e; ++i)
885 if (!isa<ConstantInt>(Ops[i]))
886 return nullptr;
887
888 unsigned BitWidth = DL.getTypeSizeInBits(IntIdxTy);
889 APInt Offset =
890 APInt(BitWidth,
891 DL.getIndexedOffsetInType(
892 SrcElemTy,
893 makeArrayRef((Value * const *)Ops.data() + 1, Ops.size() - 1)));
894 Ptr = StripPtrCastKeepAS(Ptr);
895
896 // If this is a GEP of a GEP, fold it all into a single GEP.
897 while (auto *GEP = dyn_cast<GEPOperator>(Ptr)) {
898 InnermostGEP = GEP;
899 InBounds &= GEP->isInBounds();
900
901 SmallVector<Value *, 4> NestedOps(llvm::drop_begin(GEP->operands()));
902
903 // Do not try the incorporate the sub-GEP if some index is not a number.
904 bool AllConstantInt = true;
905 for (Value *NestedOp : NestedOps)
906 if (!isa<ConstantInt>(NestedOp)) {
907 AllConstantInt = false;
908 break;
909 }
910 if (!AllConstantInt)
911 break;
912
913 Ptr = cast<Constant>(GEP->getOperand(0));
914 SrcElemTy = GEP->getSourceElementType();
915 Offset += APInt(BitWidth, DL.getIndexedOffsetInType(SrcElemTy, NestedOps));
916 Ptr = StripPtrCastKeepAS(Ptr);
917 }
918
919 // If the base value for this address is a literal integer value, fold the
920 // getelementptr to the resulting integer value casted to the pointer type.
921 APInt BasePtr(BitWidth, 0);
922 if (auto *CE = dyn_cast<ConstantExpr>(Ptr)) {
923 if (CE->getOpcode() == Instruction::IntToPtr) {
924 if (auto *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
925 BasePtr = Base->getValue().zextOrTrunc(BitWidth);
926 }
927 }
928
929 auto *PTy = cast<PointerType>(Ptr->getType());
930 if ((Ptr->isNullValue() || BasePtr != 0) &&
931 !DL.isNonIntegralPointerType(PTy)) {
932 Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr);
933 return ConstantExpr::getIntToPtr(C, ResTy);
934 }
935
936 // Otherwise form a regular getelementptr. Recompute the indices so that
937 // we eliminate over-indexing of the notional static type array bounds.
938 // This makes it easy to determine if the getelementptr is "inbounds".
939 // Also, this helps GlobalOpt do SROA on GlobalVariables.
940
941 // For GEPs of GlobalValues, use the value type even for opaque pointers.
942 // Otherwise use an i8 GEP.
943 if (auto *GV = dyn_cast<GlobalValue>(Ptr))
944 SrcElemTy = GV->getValueType();
945 else if (!PTy->isOpaque())
946 SrcElemTy = PTy->getNonOpaquePointerElementType();
947 else
948 SrcElemTy = Type::getInt8Ty(Ptr->getContext());
949
950 if (!SrcElemTy->isSized())
951 return nullptr;
952
953 Type *ElemTy = SrcElemTy;
954 SmallVector<APInt> Indices = DL.getGEPIndicesForOffset(ElemTy, Offset);
955 if (Offset != 0)
956 return nullptr;
957
958 // Try to add additional zero indices to reach the desired result element
959 // type.
960 // TODO: Should we avoid extra zero indices if ResElemTy can't be reached and
961 // we'll have to insert a bitcast anyway?
962 while (ElemTy != ResElemTy) {
963 Type *NextTy = GetElementPtrInst::getTypeAtIndex(ElemTy, (uint64_t)0);
964 if (!NextTy)
965 break;
966
967 Indices.push_back(APInt::getZero(isa<StructType>(ElemTy) ? 32 : BitWidth));
968 ElemTy = NextTy;
969 }
970
971 SmallVector<Constant *, 32> NewIdxs;
972 for (const APInt &Index : Indices)
973 NewIdxs.push_back(ConstantInt::get(
974 Type::getIntNTy(Ptr->getContext(), Index.getBitWidth()), Index));
975
976 // Preserve the inrange index from the innermost GEP if possible. We must
977 // have calculated the same indices up to and including the inrange index.
978 Optional<unsigned> InRangeIndex;
979 if (Optional<unsigned> LastIRIndex = InnermostGEP->getInRangeIndex())
980 if (SrcElemTy == InnermostGEP->getSourceElementType() &&
981 NewIdxs.size() > *LastIRIndex) {
982 InRangeIndex = LastIRIndex;
983 for (unsigned I = 0; I <= *LastIRIndex; ++I)
984 if (NewIdxs[I] != InnermostGEP->getOperand(I + 1))
985 return nullptr;
986 }
987
988 // Create a GEP.
989 Constant *C = ConstantExpr::getGetElementPtr(SrcElemTy, Ptr, NewIdxs,
990 InBounds, InRangeIndex);
991 assert((static_cast <bool> (cast<PointerType>(C->getType
())->isOpaqueOrPointeeTypeMatches(ElemTy) && "Computed GetElementPtr has unexpected type!"
) ? void (0) : __assert_fail ("cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && \"Computed GetElementPtr has unexpected type!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 993, __extension__
__PRETTY_FUNCTION__))
992 cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) &&(static_cast <bool> (cast<PointerType>(C->getType
())->isOpaqueOrPointeeTypeMatches(ElemTy) && "Computed GetElementPtr has unexpected type!"
) ? void (0) : __assert_fail ("cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && \"Computed GetElementPtr has unexpected type!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 993, __extension__
__PRETTY_FUNCTION__))
993 "Computed GetElementPtr has unexpected type!")(static_cast <bool> (cast<PointerType>(C->getType
())->isOpaqueOrPointeeTypeMatches(ElemTy) && "Computed GetElementPtr has unexpected type!"
) ? void (0) : __assert_fail ("cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && \"Computed GetElementPtr has unexpected type!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 993, __extension__
__PRETTY_FUNCTION__))
;
994
995 // If we ended up indexing a member with a type that doesn't match
996 // the type of what the original indices indexed, add a cast.
997 if (C->getType() != ResTy)
998 C = FoldBitCast(C, ResTy, DL);
999
1000 return C;
1001}
1002
1003/// Attempt to constant fold an instruction with the
1004/// specified opcode and operands. If successful, the constant result is
1005/// returned, if not, null is returned. Note that this function can fail when
1006/// attempting to fold instructions like loads and stores, which have no
1007/// constant expression form.
1008Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, unsigned Opcode,
1009 ArrayRef<Constant *> Ops,
1010 const DataLayout &DL,
1011 const TargetLibraryInfo *TLI) {
1012 Type *DestTy = InstOrCE->getType();
1013
1014 if (Instruction::isUnaryOp(Opcode))
1015 return ConstantFoldUnaryOpOperand(Opcode, Ops[0], DL);
1016
1017 if (Instruction::isBinaryOp(Opcode))
1018 return ConstantFoldBinaryOpOperands(Opcode, Ops[0], Ops[1], DL);
1019
1020 if (Instruction::isCast(Opcode))
1021 return ConstantFoldCastOperand(Opcode, Ops[0], DestTy, DL);
1022
1023 if (auto *GEP = dyn_cast<GEPOperator>(InstOrCE)) {
1024 if (Constant *C = SymbolicallyEvaluateGEP(GEP, Ops, DL, TLI))
1025 return C;
1026
1027 return ConstantExpr::getGetElementPtr(GEP->getSourceElementType(), Ops[0],
1028 Ops.slice(1), GEP->isInBounds(),
1029 GEP->getInRangeIndex());
1030 }
1031
1032 if (auto *CE = dyn_cast<ConstantExpr>(InstOrCE))
1033 return CE->getWithOperands(Ops);
1034
1035 switch (Opcode) {
1036 default: return nullptr;
1037 case Instruction::ICmp:
1038 case Instruction::FCmp: llvm_unreachable("Invalid for compares")::llvm::llvm_unreachable_internal("Invalid for compares", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1038)
;
1039 case Instruction::Freeze:
1040 return isGuaranteedNotToBeUndefOrPoison(Ops[0]) ? Ops[0] : nullptr;
1041 case Instruction::Call:
1042 if (auto *F = dyn_cast<Function>(Ops.back())) {
1043 const auto *Call = cast<CallBase>(InstOrCE);
1044 if (canConstantFoldCallTo(Call, F))
1045 return ConstantFoldCall(Call, F, Ops.slice(0, Ops.size() - 1), TLI);
1046 }
1047 return nullptr;
1048 case Instruction::Select:
1049 return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
1050 case Instruction::ExtractElement:
1051 return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
1052 case Instruction::ExtractValue:
1053 return ConstantExpr::getExtractValue(
1054 Ops[0], cast<ExtractValueInst>(InstOrCE)->getIndices());
1055 case Instruction::InsertElement:
1056 return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
1057 case Instruction::ShuffleVector:
1058 return ConstantExpr::getShuffleVector(
1059 Ops[0], Ops[1], cast<ShuffleVectorInst>(InstOrCE)->getShuffleMask());
1060 }
1061}
1062
1063} // end anonymous namespace
1064
1065//===----------------------------------------------------------------------===//
1066// Constant Folding public APIs
1067//===----------------------------------------------------------------------===//
1068
1069namespace {
1070
1071Constant *
1072ConstantFoldConstantImpl(const Constant *C, const DataLayout &DL,
1073 const TargetLibraryInfo *TLI,
1074 SmallDenseMap<Constant *, Constant *> &FoldedOps) {
1075 if (!isa<ConstantVector>(C) && !isa<ConstantExpr>(C))
1076 return const_cast<Constant *>(C);
1077
1078 SmallVector<Constant *, 8> Ops;
1079 for (const Use &OldU : C->operands()) {
1080 Constant *OldC = cast<Constant>(&OldU);
1081 Constant *NewC = OldC;
1082 // Recursively fold the ConstantExpr's operands. If we have already folded
1083 // a ConstantExpr, we don't have to process it again.
1084 if (isa<ConstantVector>(OldC) || isa<ConstantExpr>(OldC)) {
1085 auto It = FoldedOps.find(OldC);
1086 if (It == FoldedOps.end()) {
1087 NewC = ConstantFoldConstantImpl(OldC, DL, TLI, FoldedOps);
1088 FoldedOps.insert({OldC, NewC});
1089 } else {
1090 NewC = It->second;
1091 }
1092 }
1093 Ops.push_back(NewC);
1094 }
1095
1096 if (auto *CE = dyn_cast<ConstantExpr>(C)) {
1097 if (CE->isCompare())
1098 return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1],
1099 DL, TLI);
1100
1101 return ConstantFoldInstOperandsImpl(CE, CE->getOpcode(), Ops, DL, TLI);
1102 }
1103
1104 assert(isa<ConstantVector>(C))(static_cast <bool> (isa<ConstantVector>(C)) ? void
(0) : __assert_fail ("isa<ConstantVector>(C)", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1104, __extension__ __PRETTY_FUNCTION__))
;
1105 return ConstantVector::get(Ops);
1106}
1107
1108} // end anonymous namespace
1109
1110Constant *llvm::ConstantFoldInstruction(Instruction *I, const DataLayout &DL,
1111 const TargetLibraryInfo *TLI) {
1112 // Handle PHI nodes quickly here...
1113 if (auto *PN = dyn_cast<PHINode>(I)) {
1114 Constant *CommonValue = nullptr;
1115
1116 SmallDenseMap<Constant *, Constant *> FoldedOps;
1117 for (Value *Incoming : PN->incoming_values()) {
1118 // If the incoming value is undef then skip it. Note that while we could
1119 // skip the value if it is equal to the phi node itself we choose not to
1120 // because that would break the rule that constant folding only applies if
1121 // all operands are constants.
1122 if (isa<UndefValue>(Incoming))
1123 continue;
1124 // If the incoming value is not a constant, then give up.
1125 auto *C = dyn_cast<Constant>(Incoming);
1126 if (!C)
1127 return nullptr;
1128 // Fold the PHI's operands.
1129 C = ConstantFoldConstantImpl(C, DL, TLI, FoldedOps);
1130 // If the incoming value is a different constant to
1131 // the one we saw previously, then give up.
1132 if (CommonValue && C != CommonValue)
1133 return nullptr;
1134 CommonValue = C;
1135 }
1136
1137 // If we reach here, all incoming values are the same constant or undef.
1138 return CommonValue ? CommonValue : UndefValue::get(PN->getType());
1139 }
1140
1141 // Scan the operand list, checking to see if they are all constants, if so,
1142 // hand off to ConstantFoldInstOperandsImpl.
1143 if (!all_of(I->operands(), [](Use &U) { return isa<Constant>(U); }))
1144 return nullptr;
1145
1146 SmallDenseMap<Constant *, Constant *> FoldedOps;
1147 SmallVector<Constant *, 8> Ops;
1148 for (const Use &OpU : I->operands()) {
1149 auto *Op = cast<Constant>(&OpU);
1150 // Fold the Instruction's operands.
1151 Op = ConstantFoldConstantImpl(Op, DL, TLI, FoldedOps);
1152 Ops.push_back(Op);
1153 }
1154
1155 if (const auto *CI = dyn_cast<CmpInst>(I))
1156 return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
1157 DL, TLI);
1158
1159 if (const auto *LI = dyn_cast<LoadInst>(I)) {
1160 if (LI->isVolatile())
1161 return nullptr;
1162 return ConstantFoldLoadFromConstPtr(Ops[0], LI->getType(), DL);
1163 }
1164
1165 if (auto *IVI = dyn_cast<InsertValueInst>(I))
1166 return ConstantExpr::getInsertValue(Ops[0], Ops[1], IVI->getIndices());
1167
1168 if (auto *EVI = dyn_cast<ExtractValueInst>(I))
1169 return ConstantExpr::getExtractValue(Ops[0], EVI->getIndices());
1170
1171 return ConstantFoldInstOperands(I, Ops, DL, TLI);
1172}
1173
1174Constant *llvm::ConstantFoldConstant(const Constant *C, const DataLayout &DL,
1175 const TargetLibraryInfo *TLI) {
1176 SmallDenseMap<Constant *, Constant *> FoldedOps;
1177 return ConstantFoldConstantImpl(C, DL, TLI, FoldedOps);
1178}
1179
1180Constant *llvm::ConstantFoldInstOperands(Instruction *I,
1181 ArrayRef<Constant *> Ops,
1182 const DataLayout &DL,
1183 const TargetLibraryInfo *TLI) {
1184 return ConstantFoldInstOperandsImpl(I, I->getOpcode(), Ops, DL, TLI);
1185}
1186
1187Constant *llvm::ConstantFoldCompareInstOperands(unsigned IntPredicate,
1188 Constant *Ops0, Constant *Ops1,
1189 const DataLayout &DL,
1190 const TargetLibraryInfo *TLI) {
1191 CmpInst::Predicate Predicate = (CmpInst::Predicate)IntPredicate;
1192 // fold: icmp (inttoptr x), null -> icmp x, 0
1193 // fold: icmp null, (inttoptr x) -> icmp 0, x
1194 // fold: icmp (ptrtoint x), 0 -> icmp x, null
1195 // fold: icmp 0, (ptrtoint x) -> icmp null, x
1196 // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y
1197 // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y
1198 //
1199 // FIXME: The following comment is out of data and the DataLayout is here now.
1200 // ConstantExpr::getCompare cannot do this, because it doesn't have DL
1201 // around to know if bit truncation is happening.
1202 if (auto *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
1203 if (Ops1->isNullValue()) {
1204 if (CE0->getOpcode() == Instruction::IntToPtr) {
1205 Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
1206 // Convert the integer value to the right size to ensure we get the
1207 // proper extension or truncation.
1208 Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
1209 IntPtrTy, false);
1210 Constant *Null = Constant::getNullValue(C->getType());
1211 return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI);
1212 }
1213
1214 // Only do this transformation if the int is intptrty in size, otherwise
1215 // there is a truncation or extension that we aren't modeling.
1216 if (CE0->getOpcode() == Instruction::PtrToInt) {
1217 Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
1218 if (CE0->getType() == IntPtrTy) {
1219 Constant *C = CE0->getOperand(0);
1220 Constant *Null = Constant::getNullValue(C->getType());
1221 return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI);
1222 }
1223 }
1224 }
1225
1226 if (auto *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
1227 if (CE0->getOpcode() == CE1->getOpcode()) {
1228 if (CE0->getOpcode() == Instruction::IntToPtr) {
1229 Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
1230
1231 // Convert the integer value to the right size to ensure we get the
1232 // proper extension or truncation.
1233 Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0),
1234 IntPtrTy, false);
1235 Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0),
1236 IntPtrTy, false);
1237 return ConstantFoldCompareInstOperands(Predicate, C0, C1, DL, TLI);
1238 }
1239
1240 // Only do this transformation if the int is intptrty in size, otherwise
1241 // there is a truncation or extension that we aren't modeling.
1242 if (CE0->getOpcode() == Instruction::PtrToInt) {
1243 Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
1244 if (CE0->getType() == IntPtrTy &&
1245 CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()) {
1246 return ConstantFoldCompareInstOperands(
1247 Predicate, CE0->getOperand(0), CE1->getOperand(0), DL, TLI);
1248 }
1249 }
1250 }
1251 }
1252
1253 // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
1254 // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
1255 if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
1256 CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
1257 Constant *LHS = ConstantFoldCompareInstOperands(
1258 Predicate, CE0->getOperand(0), Ops1, DL, TLI);
1259 Constant *RHS = ConstantFoldCompareInstOperands(
1260 Predicate, CE0->getOperand(1), Ops1, DL, TLI);
1261 unsigned OpC =
1262 Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
1263 return ConstantFoldBinaryOpOperands(OpC, LHS, RHS, DL);
1264 }
1265
1266 // Convert pointer comparison (base+offset1) pred (base+offset2) into
1267 // offset1 pred offset2, for the case where the offset is inbounds. This
1268 // only works for equality and unsigned comparison, as inbounds permits
1269 // crossing the sign boundary. However, the offset comparison itself is
1270 // signed.
1271 if (Ops0->getType()->isPointerTy() && !ICmpInst::isSigned(Predicate)) {
1272 unsigned IndexWidth = DL.getIndexTypeSizeInBits(Ops0->getType());
1273 APInt Offset0(IndexWidth, 0);
1274 Value *Stripped0 =
1275 Ops0->stripAndAccumulateInBoundsConstantOffsets(DL, Offset0);
1276 APInt Offset1(IndexWidth, 0);
1277 Value *Stripped1 =
1278 Ops1->stripAndAccumulateInBoundsConstantOffsets(DL, Offset1);
1279 if (Stripped0 == Stripped1)
1280 return ConstantExpr::getCompare(
1281 ICmpInst::getSignedPredicate(Predicate),
1282 ConstantInt::get(CE0->getContext(), Offset0),
1283 ConstantInt::get(CE0->getContext(), Offset1));
1284 }
1285 } else if (isa<ConstantExpr>(Ops1)) {
1286 // If RHS is a constant expression, but the left side isn't, swap the
1287 // operands and try again.
1288 Predicate = ICmpInst::getSwappedPredicate(Predicate);
1289 return ConstantFoldCompareInstOperands(Predicate, Ops1, Ops0, DL, TLI);
1290 }
1291
1292 return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
1293}
1294
1295Constant *llvm::ConstantFoldUnaryOpOperand(unsigned Opcode, Constant *Op,
1296 const DataLayout &DL) {
1297 assert(Instruction::isUnaryOp(Opcode))(static_cast <bool> (Instruction::isUnaryOp(Opcode)) ? void
(0) : __assert_fail ("Instruction::isUnaryOp(Opcode)", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1297, __extension__ __PRETTY_FUNCTION__))
;
1298
1299 return ConstantExpr::get(Opcode, Op);
1300}
1301
1302Constant *llvm::ConstantFoldBinaryOpOperands(unsigned Opcode, Constant *LHS,
1303 Constant *RHS,
1304 const DataLayout &DL) {
1305 assert(Instruction::isBinaryOp(Opcode))(static_cast <bool> (Instruction::isBinaryOp(Opcode)) ?
void (0) : __assert_fail ("Instruction::isBinaryOp(Opcode)",
"llvm/lib/Analysis/ConstantFolding.cpp", 1305, __extension__
__PRETTY_FUNCTION__))
;
1306 if (isa<ConstantExpr>(LHS) || isa<ConstantExpr>(RHS))
1307 if (Constant *C = SymbolicallyEvaluateBinop(Opcode, LHS, RHS, DL))
1308 return C;
1309
1310 return ConstantExpr::get(Opcode, LHS, RHS);
1311}
1312
1313Constant *llvm::ConstantFoldCastOperand(unsigned Opcode, Constant *C,
1314 Type *DestTy, const DataLayout &DL) {
1315 assert(Instruction::isCast(Opcode))(static_cast <bool> (Instruction::isCast(Opcode)) ? void
(0) : __assert_fail ("Instruction::isCast(Opcode)", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1315, __extension__ __PRETTY_FUNCTION__))
;
1316 switch (Opcode) {
1317 default:
1318 llvm_unreachable("Missing case")::llvm::llvm_unreachable_internal("Missing case", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1318)
;
1319 case Instruction::PtrToInt:
1320 if (auto *CE = dyn_cast<ConstantExpr>(C)) {
1321 Constant *FoldedValue = nullptr;
1322 // If the input is a inttoptr, eliminate the pair. This requires knowing
1323 // the width of a pointer, so it can't be done in ConstantExpr::getCast.
1324 if (CE->getOpcode() == Instruction::IntToPtr) {
1325 // zext/trunc the inttoptr to pointer size.
1326 FoldedValue = ConstantExpr::getIntegerCast(
1327 CE->getOperand(0), DL.getIntPtrType(CE->getType()),
1328 /*IsSigned=*/false);
1329 } else if (auto *GEP = dyn_cast<GEPOperator>(CE)) {
1330 // If we have GEP, we can perform the following folds:
1331 // (ptrtoint (gep null, x)) -> x
1332 // (ptrtoint (gep (gep null, x), y) -> x + y, etc.
1333 unsigned BitWidth = DL.getIndexTypeSizeInBits(GEP->getType());
1334 APInt BaseOffset(BitWidth, 0);
1335 auto *Base = cast<Constant>(GEP->stripAndAccumulateConstantOffsets(
1336 DL, BaseOffset, /*AllowNonInbounds=*/true));
1337 if (Base->isNullValue()) {
1338 FoldedValue = ConstantInt::get(CE->getContext(), BaseOffset);
1339 }
1340 }
1341 if (FoldedValue) {
1342 // Do a zext or trunc to get to the ptrtoint dest size.
1343 return ConstantExpr::getIntegerCast(FoldedValue, DestTy,
1344 /*IsSigned=*/false);
1345 }
1346 }
1347 return ConstantExpr::getCast(Opcode, C, DestTy);
1348 case Instruction::IntToPtr:
1349 // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
1350 // the int size is >= the ptr size and the address spaces are the same.
1351 // This requires knowing the width of a pointer, so it can't be done in
1352 // ConstantExpr::getCast.
1353 if (auto *CE = dyn_cast<ConstantExpr>(C)) {
1354 if (CE->getOpcode() == Instruction::PtrToInt) {
1355 Constant *SrcPtr = CE->getOperand(0);
1356 unsigned SrcPtrSize = DL.getPointerTypeSizeInBits(SrcPtr->getType());
1357 unsigned MidIntSize = CE->getType()->getScalarSizeInBits();
1358
1359 if (MidIntSize >= SrcPtrSize) {
1360 unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
1361 if (SrcAS == DestTy->getPointerAddressSpace())
1362 return FoldBitCast(CE->getOperand(0), DestTy, DL);
1363 }
1364 }
1365 }
1366
1367 return ConstantExpr::getCast(Opcode, C, DestTy);
1368 case Instruction::Trunc:
1369 case Instruction::ZExt:
1370 case Instruction::SExt:
1371 case Instruction::FPTrunc:
1372 case Instruction::FPExt:
1373 case Instruction::UIToFP:
1374 case Instruction::SIToFP:
1375 case Instruction::FPToUI:
1376 case Instruction::FPToSI:
1377 case Instruction::AddrSpaceCast:
1378 return ConstantExpr::getCast(Opcode, C, DestTy);
1379 case Instruction::BitCast:
1380 return FoldBitCast(C, DestTy, DL);
1381 }
1382}
1383
1384//===----------------------------------------------------------------------===//
1385// Constant Folding for Calls
1386//
1387
1388bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) {
1389 if (Call->isNoBuiltin())
1390 return false;
1391 if (Call->getFunctionType() != F->getFunctionType())
1392 return false;
1393 switch (F->getIntrinsicID()) {
1394 // Operations that do not operate floating-point numbers and do not depend on
1395 // FP environment can be folded even in strictfp functions.
1396 case Intrinsic::bswap:
1397 case Intrinsic::ctpop:
1398 case Intrinsic::ctlz:
1399 case Intrinsic::cttz:
1400 case Intrinsic::fshl:
1401 case Intrinsic::fshr:
1402 case Intrinsic::launder_invariant_group:
1403 case Intrinsic::strip_invariant_group:
1404 case Intrinsic::masked_load:
1405 case Intrinsic::get_active_lane_mask:
1406 case Intrinsic::abs:
1407 case Intrinsic::smax:
1408 case Intrinsic::smin:
1409 case Intrinsic::umax:
1410 case Intrinsic::umin:
1411 case Intrinsic::sadd_with_overflow:
1412 case Intrinsic::uadd_with_overflow:
1413 case Intrinsic::ssub_with_overflow:
1414 case Intrinsic::usub_with_overflow:
1415 case Intrinsic::smul_with_overflow:
1416 case Intrinsic::umul_with_overflow:
1417 case Intrinsic::sadd_sat:
1418 case Intrinsic::uadd_sat:
1419 case Intrinsic::ssub_sat:
1420 case Intrinsic::usub_sat:
1421 case Intrinsic::smul_fix:
1422 case Intrinsic::smul_fix_sat:
1423 case Intrinsic::bitreverse:
1424 case Intrinsic::is_constant:
1425 case Intrinsic::vector_reduce_add:
1426 case Intrinsic::vector_reduce_mul:
1427 case Intrinsic::vector_reduce_and:
1428 case Intrinsic::vector_reduce_or:
1429 case Intrinsic::vector_reduce_xor:
1430 case Intrinsic::vector_reduce_smin:
1431 case Intrinsic::vector_reduce_smax:
1432 case Intrinsic::vector_reduce_umin:
1433 case Intrinsic::vector_reduce_umax:
1434 // Target intrinsics
1435 case Intrinsic::amdgcn_perm:
1436 case Intrinsic::arm_mve_vctp8:
1437 case Intrinsic::arm_mve_vctp16:
1438 case Intrinsic::arm_mve_vctp32:
1439 case Intrinsic::arm_mve_vctp64:
1440 case Intrinsic::aarch64_sve_convert_from_svbool:
1441 // WebAssembly float semantics are always known
1442 case Intrinsic::wasm_trunc_signed:
1443 case Intrinsic::wasm_trunc_unsigned:
1444 return true;
1445
1446 // Floating point operations cannot be folded in strictfp functions in
1447 // general case. They can be folded if FP environment is known to compiler.
1448 case Intrinsic::minnum:
1449 case Intrinsic::maxnum:
1450 case Intrinsic::minimum:
1451 case Intrinsic::maximum:
1452 case Intrinsic::log:
1453 case Intrinsic::log2:
1454 case Intrinsic::log10:
1455 case Intrinsic::exp:
1456 case Intrinsic::exp2:
1457 case Intrinsic::sqrt:
1458 case Intrinsic::sin:
1459 case Intrinsic::cos:
1460 case Intrinsic::pow:
1461 case Intrinsic::powi:
1462 case Intrinsic::fma:
1463 case Intrinsic::fmuladd:
1464 case Intrinsic::fptoui_sat:
1465 case Intrinsic::fptosi_sat:
1466 case Intrinsic::convert_from_fp16:
1467 case Intrinsic::convert_to_fp16:
1468 case Intrinsic::amdgcn_cos:
1469 case Intrinsic::amdgcn_cubeid:
1470 case Intrinsic::amdgcn_cubema:
1471 case Intrinsic::amdgcn_cubesc:
1472 case Intrinsic::amdgcn_cubetc:
1473 case Intrinsic::amdgcn_fmul_legacy:
1474 case Intrinsic::amdgcn_fma_legacy:
1475 case Intrinsic::amdgcn_fract:
1476 case Intrinsic::amdgcn_ldexp:
1477 case Intrinsic::amdgcn_sin:
1478 // The intrinsics below depend on rounding mode in MXCSR.
1479 case Intrinsic::x86_sse_cvtss2si:
1480 case Intrinsic::x86_sse_cvtss2si64:
1481 case Intrinsic::x86_sse_cvttss2si:
1482 case Intrinsic::x86_sse_cvttss2si64:
1483 case Intrinsic::x86_sse2_cvtsd2si:
1484 case Intrinsic::x86_sse2_cvtsd2si64:
1485 case Intrinsic::x86_sse2_cvttsd2si:
1486 case Intrinsic::x86_sse2_cvttsd2si64:
1487 case Intrinsic::x86_avx512_vcvtss2si32:
1488 case Intrinsic::x86_avx512_vcvtss2si64:
1489 case Intrinsic::x86_avx512_cvttss2si:
1490 case Intrinsic::x86_avx512_cvttss2si64:
1491 case Intrinsic::x86_avx512_vcvtsd2si32:
1492 case Intrinsic::x86_avx512_vcvtsd2si64:
1493 case Intrinsic::x86_avx512_cvttsd2si:
1494 case Intrinsic::x86_avx512_cvttsd2si64:
1495 case Intrinsic::x86_avx512_vcvtss2usi32:
1496 case Intrinsic::x86_avx512_vcvtss2usi64:
1497 case Intrinsic::x86_avx512_cvttss2usi:
1498 case Intrinsic::x86_avx512_cvttss2usi64:
1499 case Intrinsic::x86_avx512_vcvtsd2usi32:
1500 case Intrinsic::x86_avx512_vcvtsd2usi64:
1501 case Intrinsic::x86_avx512_cvttsd2usi:
1502 case Intrinsic::x86_avx512_cvttsd2usi64:
1503 return !Call->isStrictFP();
1504
1505 // Sign operations are actually bitwise operations, they do not raise
1506 // exceptions even for SNANs.
1507 case Intrinsic::fabs:
1508 case Intrinsic::copysign:
1509 // Non-constrained variants of rounding operations means default FP
1510 // environment, they can be folded in any case.
1511 case Intrinsic::ceil:
1512 case Intrinsic::floor:
1513 case Intrinsic::round:
1514 case Intrinsic::roundeven:
1515 case Intrinsic::trunc:
1516 case Intrinsic::nearbyint:
1517 case Intrinsic::rint:
1518 // Constrained intrinsics can be folded if FP environment is known
1519 // to compiler.
1520 case Intrinsic::experimental_constrained_fma:
1521 case Intrinsic::experimental_constrained_fmuladd:
1522 case Intrinsic::experimental_constrained_fadd:
1523 case Intrinsic::experimental_constrained_fsub:
1524 case Intrinsic::experimental_constrained_fmul:
1525 case Intrinsic::experimental_constrained_fdiv:
1526 case Intrinsic::experimental_constrained_frem:
1527 case Intrinsic::experimental_constrained_ceil:
1528 case Intrinsic::experimental_constrained_floor:
1529 case Intrinsic::experimental_constrained_round:
1530 case Intrinsic::experimental_constrained_roundeven:
1531 case Intrinsic::experimental_constrained_trunc:
1532 case Intrinsic::experimental_constrained_nearbyint:
1533 case Intrinsic::experimental_constrained_rint:
1534 case Intrinsic::experimental_constrained_fcmp:
1535 case Intrinsic::experimental_constrained_fcmps:
1536 return true;
1537 default:
1538 return false;
1539 case Intrinsic::not_intrinsic: break;
1540 }
1541
1542 if (!F->hasName() || Call->isStrictFP())
1543 return false;
1544
1545 // In these cases, the check of the length is required. We don't want to
1546 // return true for a name like "cos\0blah" which strcmp would return equal to
1547 // "cos", but has length 8.
1548 StringRef Name = F->getName();
1549 switch (Name[0]) {
1550 default:
1551 return false;
1552 case 'a':
1553 return Name == "acos" || Name == "acosf" ||
1554 Name == "asin" || Name == "asinf" ||
1555 Name == "atan" || Name == "atanf" ||
1556 Name == "atan2" || Name == "atan2f";
1557 case 'c':
1558 return Name == "ceil" || Name == "ceilf" ||
1559 Name == "cos" || Name == "cosf" ||
1560 Name == "cosh" || Name == "coshf";
1561 case 'e':
1562 return Name == "exp" || Name == "expf" ||
1563 Name == "exp2" || Name == "exp2f";
1564 case 'f':
1565 return Name == "fabs" || Name == "fabsf" ||
1566 Name == "floor" || Name == "floorf" ||
1567 Name == "fmod" || Name == "fmodf";
1568 case 'l':
1569 return Name == "log" || Name == "logf" ||
1570 Name == "log2" || Name == "log2f" ||
1571 Name == "log10" || Name == "log10f";
1572 case 'n':
1573 return Name == "nearbyint" || Name == "nearbyintf";
1574 case 'p':
1575 return Name == "pow" || Name == "powf";
1576 case 'r':
1577 return Name == "remainder" || Name == "remainderf" ||
1578 Name == "rint" || Name == "rintf" ||
1579 Name == "round" || Name == "roundf";
1580 case 's':
1581 return Name == "sin" || Name == "sinf" ||
1582 Name == "sinh" || Name == "sinhf" ||
1583 Name == "sqrt" || Name == "sqrtf";
1584 case 't':
1585 return Name == "tan" || Name == "tanf" ||
1586 Name == "tanh" || Name == "tanhf" ||
1587 Name == "trunc" || Name == "truncf";
1588 case '_':
1589 // Check for various function names that get used for the math functions
1590 // when the header files are preprocessed with the macro
1591 // __FINITE_MATH_ONLY__ enabled.
1592 // The '12' here is the length of the shortest name that can match.
1593 // We need to check the size before looking at Name[1] and Name[2]
1594 // so we may as well check a limit that will eliminate mismatches.
1595 if (Name.size() < 12 || Name[1] != '_')
1596 return false;
1597 switch (Name[2]) {
1598 default:
1599 return false;
1600 case 'a':
1601 return Name == "__acos_finite" || Name == "__acosf_finite" ||
1602 Name == "__asin_finite" || Name == "__asinf_finite" ||
1603 Name == "__atan2_finite" || Name == "__atan2f_finite";
1604 case 'c':
1605 return Name == "__cosh_finite" || Name == "__coshf_finite";
1606 case 'e':
1607 return Name == "__exp_finite" || Name == "__expf_finite" ||
1608 Name == "__exp2_finite" || Name == "__exp2f_finite";
1609 case 'l':
1610 return Name == "__log_finite" || Name == "__logf_finite" ||
1611 Name == "__log10_finite" || Name == "__log10f_finite";
1612 case 'p':
1613 return Name == "__pow_finite" || Name == "__powf_finite";
1614 case 's':
1615 return Name == "__sinh_finite" || Name == "__sinhf_finite";
1616 }
1617 }
1618}
1619
1620namespace {
1621
1622Constant *GetConstantFoldFPValue(double V, Type *Ty) {
1623 if (Ty->isHalfTy() || Ty->isFloatTy()) {
1624 APFloat APF(V);
1625 bool unused;
1626 APF.convert(Ty->getFltSemantics(), APFloat::rmNearestTiesToEven, &unused);
1627 return ConstantFP::get(Ty->getContext(), APF);
1628 }
1629 if (Ty->isDoubleTy())
1630 return ConstantFP::get(Ty->getContext(), APFloat(V));
1631 llvm_unreachable("Can only constant fold half/float/double")::llvm::llvm_unreachable_internal("Can only constant fold half/float/double"
, "llvm/lib/Analysis/ConstantFolding.cpp", 1631)
;
1632}
1633
1634/// Clear the floating-point exception state.
1635inline void llvm_fenv_clearexcept() {
1636#if defined(HAVE_FENV_H1) && HAVE_DECL_FE_ALL_EXCEPT1
1637 feclearexcept(FE_ALL_EXCEPT(0x20 | 0x04 | 0x10 | 0x08 | 0x01));
1638#endif
1639 errno(*__errno_location ()) = 0;
1640}
1641
1642/// Test if a floating-point exception was raised.
1643inline bool llvm_fenv_testexcept() {
1644 int errno_val = errno(*__errno_location ());
1645 if (errno_val == ERANGE34 || errno_val == EDOM33)
1646 return true;
1647#if defined(HAVE_FENV_H1) && HAVE_DECL_FE_ALL_EXCEPT1 && HAVE_DECL_FE_INEXACT1
1648 if (fetestexcept(FE_ALL_EXCEPT(0x20 | 0x04 | 0x10 | 0x08 | 0x01) & ~FE_INEXACT0x20))
1649 return true;
1650#endif
1651 return false;
1652}
1653
1654Constant *ConstantFoldFP(double (*NativeFP)(double), const APFloat &V,
1655 Type *Ty) {
1656 llvm_fenv_clearexcept();
1657 double Result = NativeFP(V.convertToDouble());
1658 if (llvm_fenv_testexcept()) {
1659 llvm_fenv_clearexcept();
1660 return nullptr;
1661 }
1662
1663 return GetConstantFoldFPValue(Result, Ty);
1664}
1665
1666Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
1667 const APFloat &V, const APFloat &W, Type *Ty) {
1668 llvm_fenv_clearexcept();
1669 double Result = NativeFP(V.convertToDouble(), W.convertToDouble());
1670 if (llvm_fenv_testexcept()) {
1671 llvm_fenv_clearexcept();
1672 return nullptr;
1673 }
1674
1675 return GetConstantFoldFPValue(Result, Ty);
1676}
1677
1678Constant *constantFoldVectorReduce(Intrinsic::ID IID, Constant *Op) {
1679 FixedVectorType *VT = dyn_cast<FixedVectorType>(Op->getType());
1680 if (!VT)
1681 return nullptr;
1682
1683 // This isn't strictly necessary, but handle the special/common case of zero:
1684 // all integer reductions of a zero input produce zero.
1685 if (isa<ConstantAggregateZero>(Op))
1686 return ConstantInt::get(VT->getElementType(), 0);
1687
1688 // This is the same as the underlying binops - poison propagates.
1689 if (isa<PoisonValue>(Op) || Op->containsPoisonElement())
1690 return PoisonValue::get(VT->getElementType());
1691
1692 // TODO: Handle undef.
1693 if (!isa<ConstantVector>(Op) && !isa<ConstantDataVector>(Op))
1694 return nullptr;
1695
1696 auto *EltC = dyn_cast<ConstantInt>(Op->getAggregateElement(0U));
1697 if (!EltC)
1698 return nullptr;
1699
1700 APInt Acc = EltC->getValue();
1701 for (unsigned I = 1, E = VT->getNumElements(); I != E; I++) {
1702 if (!(EltC = dyn_cast<ConstantInt>(Op->getAggregateElement(I))))
1703 return nullptr;
1704 const APInt &X = EltC->getValue();
1705 switch (IID) {
1706 case Intrinsic::vector_reduce_add:
1707 Acc = Acc + X;
1708 break;
1709 case Intrinsic::vector_reduce_mul:
1710 Acc = Acc * X;
1711 break;
1712 case Intrinsic::vector_reduce_and:
1713 Acc = Acc & X;
1714 break;
1715 case Intrinsic::vector_reduce_or:
1716 Acc = Acc | X;
1717 break;
1718 case Intrinsic::vector_reduce_xor:
1719 Acc = Acc ^ X;
1720 break;
1721 case Intrinsic::vector_reduce_smin:
1722 Acc = APIntOps::smin(Acc, X);
1723 break;
1724 case Intrinsic::vector_reduce_smax:
1725 Acc = APIntOps::smax(Acc, X);
1726 break;
1727 case Intrinsic::vector_reduce_umin:
1728 Acc = APIntOps::umin(Acc, X);
1729 break;
1730 case Intrinsic::vector_reduce_umax:
1731 Acc = APIntOps::umax(Acc, X);
1732 break;
1733 }
1734 }
1735
1736 return ConstantInt::get(Op->getContext(), Acc);
1737}
1738
1739/// Attempt to fold an SSE floating point to integer conversion of a constant
1740/// floating point. If roundTowardZero is false, the default IEEE rounding is
1741/// used (toward nearest, ties to even). This matches the behavior of the
1742/// non-truncating SSE instructions in the default rounding mode. The desired
1743/// integer type Ty is used to select how many bits are available for the
1744/// result. Returns null if the conversion cannot be performed, otherwise
1745/// returns the Constant value resulting from the conversion.
1746Constant *ConstantFoldSSEConvertToInt(const APFloat &Val, bool roundTowardZero,
1747 Type *Ty, bool IsSigned) {
1748 // All of these conversion intrinsics form an integer of at most 64bits.
1749 unsigned ResultWidth = Ty->getIntegerBitWidth();
1750 assert(ResultWidth <= 64 &&(static_cast <bool> (ResultWidth <= 64 && "Can only constant fold conversions to 64 and 32 bit ints"
) ? void (0) : __assert_fail ("ResultWidth <= 64 && \"Can only constant fold conversions to 64 and 32 bit ints\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1751, __extension__
__PRETTY_FUNCTION__))
1751 "Can only constant fold conversions to 64 and 32 bit ints")(static_cast <bool> (ResultWidth <= 64 && "Can only constant fold conversions to 64 and 32 bit ints"
) ? void (0) : __assert_fail ("ResultWidth <= 64 && \"Can only constant fold conversions to 64 and 32 bit ints\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1751, __extension__
__PRETTY_FUNCTION__))
;
1752
1753 uint64_t UIntVal;
1754 bool isExact = false;
1755 APFloat::roundingMode mode = roundTowardZero? APFloat::rmTowardZero
1756 : APFloat::rmNearestTiesToEven;
1757 APFloat::opStatus status =
1758 Val.convertToInteger(makeMutableArrayRef(UIntVal), ResultWidth,
1759 IsSigned, mode, &isExact);
1760 if (status != APFloat::opOK &&
1761 (!roundTowardZero || status != APFloat::opInexact))
1762 return nullptr;
1763 return ConstantInt::get(Ty, UIntVal, IsSigned);
1764}
1765
1766double getValueAsDouble(ConstantFP *Op) {
1767 Type *Ty = Op->getType();
1768
1769 if (Ty->isBFloatTy() || Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())
1770 return Op->getValueAPF().convertToDouble();
1771
1772 bool unused;
1773 APFloat APF = Op->getValueAPF();
1774 APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &unused);
1775 return APF.convertToDouble();
1776}
1777
1778static bool getConstIntOrUndef(Value *Op, const APInt *&C) {
1779 if (auto *CI = dyn_cast<ConstantInt>(Op)) {
1780 C = &CI->getValue();
1781 return true;
1782 }
1783 if (isa<UndefValue>(Op)) {
1784 C = nullptr;
1785 return true;
1786 }
1787 return false;
1788}
1789
1790/// Checks if the given intrinsic call, which evaluates to constant, is allowed
1791/// to be folded.
1792///
1793/// \param CI Constrained intrinsic call.
1794/// \param St Exception flags raised during constant evaluation.
1795static bool mayFoldConstrained(ConstrainedFPIntrinsic *CI,
1796 APFloat::opStatus St) {
1797 Optional<RoundingMode> ORM = CI->getRoundingMode();
1798 Optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior();
1799
1800 // If the operation does not change exception status flags, it is safe
1801 // to fold.
1802 if (St == APFloat::opStatus::opOK)
1803 return true;
1804
1805 // If evaluation raised FP exception, the result can depend on rounding
1806 // mode. If the latter is unknown, folding is not possible.
1807 if (ORM && *ORM == RoundingMode::Dynamic)
1808 return false;
1809
1810 // If FP exceptions are ignored, fold the call, even if such exception is
1811 // raised.
1812 if (EB && *EB != fp::ExceptionBehavior::ebStrict)
1813 return true;
1814
1815 // Leave the calculation for runtime so that exception flags be correctly set
1816 // in hardware.
1817 return false;
1818}
1819
1820/// Returns the rounding mode that should be used for constant evaluation.
1821static RoundingMode
1822getEvaluationRoundingMode(const ConstrainedFPIntrinsic *CI) {
1823 Optional<RoundingMode> ORM = CI->getRoundingMode();
1824 if (!ORM || *ORM == RoundingMode::Dynamic)
1825 // Even if the rounding mode is unknown, try evaluating the operation.
1826 // If it does not raise inexact exception, rounding was not applied,
1827 // so the result is exact and does not depend on rounding mode. Whether
1828 // other FP exceptions are raised, it does not depend on rounding mode.
1829 return RoundingMode::NearestTiesToEven;
1830 return *ORM;
1831}
1832
1833static Constant *ConstantFoldScalarCall1(StringRef Name,
1834 Intrinsic::ID IntrinsicID,
1835 Type *Ty,
1836 ArrayRef<Constant *> Operands,
1837 const TargetLibraryInfo *TLI,
1838 const CallBase *Call) {
1839 assert(Operands.size() == 1 && "Wrong number of operands.")(static_cast <bool> (Operands.size() == 1 && "Wrong number of operands."
) ? void (0) : __assert_fail ("Operands.size() == 1 && \"Wrong number of operands.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1839, __extension__
__PRETTY_FUNCTION__))
;
1840
1841 if (IntrinsicID == Intrinsic::is_constant) {
1842 // We know we have a "Constant" argument. But we want to only
1843 // return true for manifest constants, not those that depend on
1844 // constants with unknowable values, e.g. GlobalValue or BlockAddress.
1845 if (Operands[0]->isManifestConstant())
1846 return ConstantInt::getTrue(Ty->getContext());
1847 return nullptr;
1848 }
1849 if (isa<UndefValue>(Operands[0])) {
1850 // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN.
1851 // ctpop() is between 0 and bitwidth, pick 0 for undef.
1852 // fptoui.sat and fptosi.sat can always fold to zero (for a zero input).
1853 if (IntrinsicID == Intrinsic::cos ||
1854 IntrinsicID == Intrinsic::ctpop ||
1855 IntrinsicID == Intrinsic::fptoui_sat ||
1856 IntrinsicID == Intrinsic::fptosi_sat)
1857 return Constant::getNullValue(Ty);
1858 if (IntrinsicID == Intrinsic::bswap ||
1859 IntrinsicID == Intrinsic::bitreverse ||
1860 IntrinsicID == Intrinsic::launder_invariant_group ||
1861 IntrinsicID == Intrinsic::strip_invariant_group)
1862 return Operands[0];
1863 }
1864
1865 if (isa<ConstantPointerNull>(Operands[0])) {
1866 // launder(null) == null == strip(null) iff in addrspace 0
1867 if (IntrinsicID == Intrinsic::launder_invariant_group ||
1868 IntrinsicID == Intrinsic::strip_invariant_group) {
1869 // If instruction is not yet put in a basic block (e.g. when cloning
1870 // a function during inlining), Call's caller may not be available.
1871 // So check Call's BB first before querying Call->getCaller.
1872 const Function *Caller =
1873 Call->getParent() ? Call->getCaller() : nullptr;
1874 if (Caller &&
1875 !NullPointerIsDefined(
1876 Caller, Operands[0]->getType()->getPointerAddressSpace())) {
1877 return Operands[0];
1878 }
1879 return nullptr;
1880 }
1881 }
1882
1883 if (auto *Op = dyn_cast<ConstantFP>(Operands[0])) {
1884 if (IntrinsicID == Intrinsic::convert_to_fp16) {
1885 APFloat Val(Op->getValueAPF());
1886
1887 bool lost = false;
1888 Val.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &lost);
1889
1890 return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt());
1891 }
1892
1893 APFloat U = Op->getValueAPF();
1894
1895 if (IntrinsicID == Intrinsic::wasm_trunc_signed ||
1896 IntrinsicID == Intrinsic::wasm_trunc_unsigned) {
1897 bool Signed = IntrinsicID == Intrinsic::wasm_trunc_signed;
1898
1899 if (U.isNaN())
1900 return nullptr;
1901
1902 unsigned Width = Ty->getIntegerBitWidth();
1903 APSInt Int(Width, !Signed);
1904 bool IsExact = false;
1905 APFloat::opStatus Status =
1906 U.convertToInteger(Int, APFloat::rmTowardZero, &IsExact);
1907
1908 if (Status == APFloat::opOK || Status == APFloat::opInexact)
1909 return ConstantInt::get(Ty, Int);
1910
1911 return nullptr;
1912 }
1913
1914 if (IntrinsicID == Intrinsic::fptoui_sat ||
1915 IntrinsicID == Intrinsic::fptosi_sat) {
1916 // convertToInteger() already has the desired saturation semantics.
1917 APSInt Int(Ty->getIntegerBitWidth(),
1918 IntrinsicID == Intrinsic::fptoui_sat);
1919 bool IsExact;
1920 U.convertToInteger(Int, APFloat::rmTowardZero, &IsExact);
1921 return ConstantInt::get(Ty, Int);
1922 }
1923
1924 if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
1925 return nullptr;
1926
1927 // Use internal versions of these intrinsics.
1928
1929 if (IntrinsicID == Intrinsic::nearbyint || IntrinsicID == Intrinsic::rint) {
1930 U.roundToIntegral(APFloat::rmNearestTiesToEven);
1931 return ConstantFP::get(Ty->getContext(), U);
1932 }
1933
1934 if (IntrinsicID == Intrinsic::round) {
1935 U.roundToIntegral(APFloat::rmNearestTiesToAway);
1936 return ConstantFP::get(Ty->getContext(), U);
1937 }
1938
1939 if (IntrinsicID == Intrinsic::roundeven) {
1940 U.roundToIntegral(APFloat::rmNearestTiesToEven);
1941 return ConstantFP::get(Ty->getContext(), U);
1942 }
1943
1944 if (IntrinsicID == Intrinsic::ceil) {
1945 U.roundToIntegral(APFloat::rmTowardPositive);
1946 return ConstantFP::get(Ty->getContext(), U);
1947 }
1948
1949 if (IntrinsicID == Intrinsic::floor) {
1950 U.roundToIntegral(APFloat::rmTowardNegative);
1951 return ConstantFP::get(Ty->getContext(), U);
1952 }
1953
1954 if (IntrinsicID == Intrinsic::trunc) {
1955 U.roundToIntegral(APFloat::rmTowardZero);
1956 return ConstantFP::get(Ty->getContext(), U);
1957 }
1958
1959 if (IntrinsicID == Intrinsic::fabs) {
1960 U.clearSign();
1961 return ConstantFP::get(Ty->getContext(), U);
1962 }
1963
1964 if (IntrinsicID == Intrinsic::amdgcn_fract) {
1965 // The v_fract instruction behaves like the OpenCL spec, which defines
1966 // fract(x) as fmin(x - floor(x), 0x1.fffffep-1f): "The min() operator is
1967 // there to prevent fract(-small) from returning 1.0. It returns the
1968 // largest positive floating-point number less than 1.0."
1969 APFloat FloorU(U);
1970 FloorU.roundToIntegral(APFloat::rmTowardNegative);
1971 APFloat FractU(U - FloorU);
1972 APFloat AlmostOne(U.getSemantics(), 1);
1973 AlmostOne.next(/*nextDown*/ true);
1974 return ConstantFP::get(Ty->getContext(), minimum(FractU, AlmostOne));
1975 }
1976
1977 // Rounding operations (floor, trunc, ceil, round and nearbyint) do not
1978 // raise FP exceptions, unless the argument is signaling NaN.
1979
1980 Optional<APFloat::roundingMode> RM;
1981 switch (IntrinsicID) {
1982 default:
1983 break;
1984 case Intrinsic::experimental_constrained_nearbyint:
1985 case Intrinsic::experimental_constrained_rint: {
1986 auto CI = cast<ConstrainedFPIntrinsic>(Call);
1987 RM = CI->getRoundingMode();
1988 if (!RM || RM.getValue() == RoundingMode::Dynamic)
1989 return nullptr;
1990 break;
1991 }
1992 case Intrinsic::experimental_constrained_round:
1993 RM = APFloat::rmNearestTiesToAway;
1994 break;
1995 case Intrinsic::experimental_constrained_ceil:
1996 RM = APFloat::rmTowardPositive;
1997 break;
1998 case Intrinsic::experimental_constrained_floor:
1999 RM = APFloat::rmTowardNegative;
2000 break;
2001 case Intrinsic::experimental_constrained_trunc:
2002 RM = APFloat::rmTowardZero;
2003 break;
2004 }
2005 if (RM) {
2006 auto CI = cast<ConstrainedFPIntrinsic>(Call);
2007 if (U.isFinite()) {
2008 APFloat::opStatus St = U.roundToIntegral(*RM);
2009 if (IntrinsicID == Intrinsic::experimental_constrained_rint &&
2010 St == APFloat::opInexact) {
2011 Optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior();
2012 if (EB && *EB == fp::ebStrict)
2013 return nullptr;
2014 }
2015 } else if (U.isSignaling()) {
2016 Optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior();
2017 if (EB && *EB != fp::ebIgnore)
2018 return nullptr;
2019 U = APFloat::getQNaN(U.getSemantics());
2020 }
2021 return ConstantFP::get(Ty->getContext(), U);
2022 }
2023
2024 /// We only fold functions with finite arguments. Folding NaN and inf is
2025 /// likely to be aborted with an exception anyway, and some host libms
2026 /// have known errors raising exceptions.
2027 if (!U.isFinite())
2028 return nullptr;
2029
2030 /// Currently APFloat versions of these functions do not exist, so we use
2031 /// the host native double versions. Float versions are not called
2032 /// directly but for all these it is true (float)(f((double)arg)) ==
2033 /// f(arg). Long double not supported yet.
2034 const APFloat &APF = Op->getValueAPF();
2035
2036 switch (IntrinsicID) {
2037 default: break;
2038 case Intrinsic::log:
2039 return ConstantFoldFP(log, APF, Ty);
2040 case Intrinsic::log2:
2041 // TODO: What about hosts that lack a C99 library?
2042 return ConstantFoldFP(Log2, APF, Ty);
2043 case Intrinsic::log10:
2044 // TODO: What about hosts that lack a C99 library?
2045 return ConstantFoldFP(log10, APF, Ty);
2046 case Intrinsic::exp:
2047 return ConstantFoldFP(exp, APF, Ty);
2048 case Intrinsic::exp2:
2049 // Fold exp2(x) as pow(2, x), in case the host lacks a C99 library.
2050 return ConstantFoldBinaryFP(pow, APFloat(2.0), APF, Ty);
2051 case Intrinsic::sin:
2052 return ConstantFoldFP(sin, APF, Ty);
2053 case Intrinsic::cos:
2054 return ConstantFoldFP(cos, APF, Ty);
2055 case Intrinsic::sqrt:
2056 return ConstantFoldFP(sqrt, APF, Ty);
2057 case Intrinsic::amdgcn_cos:
2058 case Intrinsic::amdgcn_sin: {
2059 double V = getValueAsDouble(Op);
2060 if (V < -256.0 || V > 256.0)
2061 // The gfx8 and gfx9 architectures handle arguments outside the range
2062 // [-256, 256] differently. This should be a rare case so bail out
2063 // rather than trying to handle the difference.
2064 return nullptr;
2065 bool IsCos = IntrinsicID == Intrinsic::amdgcn_cos;
2066 double V4 = V * 4.0;
2067 if (V4 == floor(V4)) {
2068 // Force exact results for quarter-integer inputs.
2069 const double SinVals[4] = { 0.0, 1.0, 0.0, -1.0 };
2070 V = SinVals[((int)V4 + (IsCos ? 1 : 0)) & 3];
2071 } else {
2072 if (IsCos)
2073 V = cos(V * 2.0 * numbers::pi);
2074 else
2075 V = sin(V * 2.0 * numbers::pi);
2076 }
2077 return GetConstantFoldFPValue(V, Ty);
2078 }
2079 }
2080
2081 if (!TLI)
2082 return nullptr;
2083
2084 LibFunc Func = NotLibFunc;
2085 if (!TLI->getLibFunc(Name, Func))
2086 return nullptr;
2087
2088 switch (Func) {
2089 default:
2090 break;
2091 case LibFunc_acos:
2092 case LibFunc_acosf:
2093 case LibFunc_acos_finite:
2094 case LibFunc_acosf_finite:
2095 if (TLI->has(Func))
2096 return ConstantFoldFP(acos, APF, Ty);
2097 break;
2098 case LibFunc_asin:
2099 case LibFunc_asinf:
2100 case LibFunc_asin_finite:
2101 case LibFunc_asinf_finite:
2102 if (TLI->has(Func))
2103 return ConstantFoldFP(asin, APF, Ty);
2104 break;
2105 case LibFunc_atan:
2106 case LibFunc_atanf:
2107 if (TLI->has(Func))
2108 return ConstantFoldFP(atan, APF, Ty);
2109 break;
2110 case LibFunc_ceil:
2111 case LibFunc_ceilf:
2112 if (TLI->has(Func)) {
2113 U.roundToIntegral(APFloat::rmTowardPositive);
2114 return ConstantFP::get(Ty->getContext(), U);
2115 }
2116 break;
2117 case LibFunc_cos:
2118 case LibFunc_cosf:
2119 if (TLI->has(Func))
2120 return ConstantFoldFP(cos, APF, Ty);
2121 break;
2122 case LibFunc_cosh:
2123 case LibFunc_coshf:
2124 case LibFunc_cosh_finite:
2125 case LibFunc_coshf_finite:
2126 if (TLI->has(Func))
2127 return ConstantFoldFP(cosh, APF, Ty);
2128 break;
2129 case LibFunc_exp:
2130 case LibFunc_expf:
2131 case LibFunc_exp_finite:
2132 case LibFunc_expf_finite:
2133 if (TLI->has(Func))
2134 return ConstantFoldFP(exp, APF, Ty);
2135 break;
2136 case LibFunc_exp2:
2137 case LibFunc_exp2f:
2138 case LibFunc_exp2_finite:
2139 case LibFunc_exp2f_finite:
2140 if (TLI->has(Func))
2141 // Fold exp2(x) as pow(2, x), in case the host lacks a C99 library.
2142 return ConstantFoldBinaryFP(pow, APFloat(2.0), APF, Ty);
2143 break;
2144 case LibFunc_fabs:
2145 case LibFunc_fabsf:
2146 if (TLI->has(Func)) {
2147 U.clearSign();
2148 return ConstantFP::get(Ty->getContext(), U);
2149 }
2150 break;
2151 case LibFunc_floor:
2152 case LibFunc_floorf:
2153 if (TLI->has(Func)) {
2154 U.roundToIntegral(APFloat::rmTowardNegative);
2155 return ConstantFP::get(Ty->getContext(), U);
2156 }
2157 break;
2158 case LibFunc_log:
2159 case LibFunc_logf:
2160 case LibFunc_log_finite:
2161 case LibFunc_logf_finite:
2162 if (!APF.isNegative() && !APF.isZero() && TLI->has(Func))
2163 return ConstantFoldFP(log, APF, Ty);
2164 break;
2165 case LibFunc_log2:
2166 case LibFunc_log2f:
2167 case LibFunc_log2_finite:
2168 case LibFunc_log2f_finite:
2169 if (!APF.isNegative() && !APF.isZero() && TLI->has(Func))
2170 // TODO: What about hosts that lack a C99 library?
2171 return ConstantFoldFP(Log2, APF, Ty);
2172 break;
2173 case LibFunc_log10:
2174 case LibFunc_log10f:
2175 case LibFunc_log10_finite:
2176 case LibFunc_log10f_finite:
2177 if (!APF.isNegative() && !APF.isZero() && TLI->has(Func))
2178 // TODO: What about hosts that lack a C99 library?
2179 return ConstantFoldFP(log10, APF, Ty);
2180 break;
2181 case LibFunc_nearbyint:
2182 case LibFunc_nearbyintf:
2183 case LibFunc_rint:
2184 case LibFunc_rintf:
2185 if (TLI->has(Func)) {
2186 U.roundToIntegral(APFloat::rmNearestTiesToEven);
2187 return ConstantFP::get(Ty->getContext(), U);
2188 }
2189 break;
2190 case LibFunc_round:
2191 case LibFunc_roundf:
2192 if (TLI->has(Func)) {
2193 U.roundToIntegral(APFloat::rmNearestTiesToAway);
2194 return ConstantFP::get(Ty->getContext(), U);
2195 }
2196 break;
2197 case LibFunc_sin:
2198 case LibFunc_sinf:
2199 if (TLI->has(Func))
2200 return ConstantFoldFP(sin, APF, Ty);
2201 break;
2202 case LibFunc_sinh:
2203 case LibFunc_sinhf:
2204 case LibFunc_sinh_finite:
2205 case LibFunc_sinhf_finite:
2206 if (TLI->has(Func))
2207 return ConstantFoldFP(sinh, APF, Ty);
2208 break;
2209 case LibFunc_sqrt:
2210 case LibFunc_sqrtf:
2211 if (!APF.isNegative() && TLI->has(Func))
2212 return ConstantFoldFP(sqrt, APF, Ty);
2213 break;
2214 case LibFunc_tan:
2215 case LibFunc_tanf:
2216 if (TLI->has(Func))
2217 return ConstantFoldFP(tan, APF, Ty);
2218 break;
2219 case LibFunc_tanh:
2220 case LibFunc_tanhf:
2221 if (TLI->has(Func))
2222 return ConstantFoldFP(tanh, APF, Ty);
2223 break;
2224 case LibFunc_trunc:
2225 case LibFunc_truncf:
2226 if (TLI->has(Func)) {
2227 U.roundToIntegral(APFloat::rmTowardZero);
2228 return ConstantFP::get(Ty->getContext(), U);
2229 }
2230 break;
2231 }
2232 return nullptr;
2233 }
2234
2235 if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) {
2236 switch (IntrinsicID) {
2237 case Intrinsic::bswap:
2238 return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap());
2239 case Intrinsic::ctpop:
2240 return ConstantInt::get(Ty, Op->getValue().countPopulation());
2241 case Intrinsic::bitreverse:
2242 return ConstantInt::get(Ty->getContext(), Op->getValue().reverseBits());
2243 case Intrinsic::convert_from_fp16: {
2244 APFloat Val(APFloat::IEEEhalf(), Op->getValue());
2245
2246 bool lost = false;
2247 APFloat::opStatus status = Val.convert(
2248 Ty->getFltSemantics(), APFloat::rmNearestTiesToEven, &lost);
2249
2250 // Conversion is always precise.
2251 (void)status;
2252 assert(status == APFloat::opOK && !lost &&(static_cast <bool> (status == APFloat::opOK &&
!lost && "Precision lost during fp16 constfolding") ?
void (0) : __assert_fail ("status == APFloat::opOK && !lost && \"Precision lost during fp16 constfolding\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2253, __extension__
__PRETTY_FUNCTION__))
2253 "Precision lost during fp16 constfolding")(static_cast <bool> (status == APFloat::opOK &&
!lost && "Precision lost during fp16 constfolding") ?
void (0) : __assert_fail ("status == APFloat::opOK && !lost && \"Precision lost during fp16 constfolding\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2253, __extension__
__PRETTY_FUNCTION__))
;
2254
2255 return ConstantFP::get(Ty->getContext(), Val);
2256 }
2257 default:
2258 return nullptr;
2259 }
2260 }
2261
2262 switch (IntrinsicID) {
2263 default: break;
2264 case Intrinsic::vector_reduce_add:
2265 case Intrinsic::vector_reduce_mul:
2266 case Intrinsic::vector_reduce_and:
2267 case Intrinsic::vector_reduce_or:
2268 case Intrinsic::vector_reduce_xor:
2269 case Intrinsic::vector_reduce_smin:
2270 case Intrinsic::vector_reduce_smax:
2271 case Intrinsic::vector_reduce_umin:
2272 case Intrinsic::vector_reduce_umax:
2273 if (Constant *C = constantFoldVectorReduce(IntrinsicID, Operands[0]))
2274 return C;
2275 break;
2276 }
2277
2278 // Support ConstantVector in case we have an Undef in the top.
2279 if (isa<ConstantVector>(Operands[0]) ||
2280 isa<ConstantDataVector>(Operands[0])) {
2281 auto *Op = cast<Constant>(Operands[0]);
2282 switch (IntrinsicID) {
2283 default: break;
2284 case Intrinsic::x86_sse_cvtss2si:
2285 case Intrinsic::x86_sse_cvtss2si64:
2286 case Intrinsic::x86_sse2_cvtsd2si:
2287 case Intrinsic::x86_sse2_cvtsd2si64:
2288 if (ConstantFP *FPOp =
2289 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
2290 return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
2291 /*roundTowardZero=*/false, Ty,
2292 /*IsSigned*/true);
2293 break;
2294 case Intrinsic::x86_sse_cvttss2si:
2295 case Intrinsic::x86_sse_cvttss2si64:
2296 case Intrinsic::x86_sse2_cvttsd2si:
2297 case Intrinsic::x86_sse2_cvttsd2si64:
2298 if (ConstantFP *FPOp =
2299 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
2300 return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
2301 /*roundTowardZero=*/true, Ty,
2302 /*IsSigned*/true);
2303 break;
2304 }
2305 }
2306
2307 return nullptr;
2308}
2309
2310static Constant *evaluateCompare(const APFloat &Op1, const APFloat &Op2,
2311 const ConstrainedFPIntrinsic *Call) {
2312 APFloat::opStatus St = APFloat::opOK;
2313 auto *FCmp = cast<ConstrainedFPCmpIntrinsic>(Call);
2314 FCmpInst::Predicate Cond = FCmp->getPredicate();
2315 if (FCmp->isSignaling()) {
2316 if (Op1.isNaN() || Op2.isNaN())
2317 St = APFloat::opInvalidOp;
2318 } else {
2319 if (Op1.isSignaling() || Op2.isSignaling())
2320 St = APFloat::opInvalidOp;
2321 }
2322 bool Result = FCmpInst::compare(Op1, Op2, Cond);
2323 if (mayFoldConstrained(const_cast<ConstrainedFPCmpIntrinsic *>(FCmp), St))
2324 return ConstantInt::get(Call->getType()->getScalarType(), Result);
2325 return nullptr;
2326}
2327
2328static Constant *ConstantFoldScalarCall2(StringRef Name,
2329 Intrinsic::ID IntrinsicID,
2330 Type *Ty,
2331 ArrayRef<Constant *> Operands,
2332 const TargetLibraryInfo *TLI,
2333 const CallBase *Call) {
2334 assert(Operands.size() == 2 && "Wrong number of operands.")(static_cast <bool> (Operands.size() == 2 && "Wrong number of operands."
) ? void (0) : __assert_fail ("Operands.size() == 2 && \"Wrong number of operands.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2334, __extension__
__PRETTY_FUNCTION__))
;
2335
2336 if (Ty->isFloatingPointTy()) {
2337 // TODO: We should have undef handling for all of the FP intrinsics that
2338 // are attempted to be folded in this function.
2339 bool IsOp0Undef = isa<UndefValue>(Operands[0]);
2340 bool IsOp1Undef = isa<UndefValue>(Operands[1]);
2341 switch (IntrinsicID) {
2342 case Intrinsic::maxnum:
2343 case Intrinsic::minnum:
2344 case Intrinsic::maximum:
2345 case Intrinsic::minimum:
2346 // If one argument is undef, return the other argument.
2347 if (IsOp0Undef)
2348 return Operands[1];
2349 if (IsOp1Undef)
2350 return Operands[0];
2351 break;
2352 }
2353 }
2354
2355 if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
2356 const APFloat &Op1V = Op1->getValueAPF();
2357
2358 if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
2359 if (Op2->getType() != Op1->getType())
2360 return nullptr;
2361 const APFloat &Op2V = Op2->getValueAPF();
2362
2363 if (const auto *ConstrIntr = dyn_cast<ConstrainedFPIntrinsic>(Call)) {
2364 RoundingMode RM = getEvaluationRoundingMode(ConstrIntr);
2365 APFloat Res = Op1V;
2366 APFloat::opStatus St;
2367 switch (IntrinsicID) {
2368 default:
2369 return nullptr;
2370 case Intrinsic::experimental_constrained_fadd:
2371 St = Res.add(Op2V, RM);
2372 break;
2373 case Intrinsic::experimental_constrained_fsub:
2374 St = Res.subtract(Op2V, RM);
2375 break;
2376 case Intrinsic::experimental_constrained_fmul:
2377 St = Res.multiply(Op2V, RM);
2378 break;
2379 case Intrinsic::experimental_constrained_fdiv:
2380 St = Res.divide(Op2V, RM);
2381 break;
2382 case Intrinsic::experimental_constrained_frem:
2383 St = Res.mod(Op2V);
2384 break;
2385 case Intrinsic::experimental_constrained_fcmp:
2386 case Intrinsic::experimental_constrained_fcmps:
2387 return evaluateCompare(Op1V, Op2V, ConstrIntr);
2388 }
2389 if (mayFoldConstrained(const_cast<ConstrainedFPIntrinsic *>(ConstrIntr),
2390 St))
2391 return ConstantFP::get(Ty->getContext(), Res);
2392 return nullptr;
2393 }
2394
2395 switch (IntrinsicID) {
2396 default:
2397 break;
2398 case Intrinsic::copysign:
2399 return ConstantFP::get(Ty->getContext(), APFloat::copySign(Op1V, Op2V));
2400 case Intrinsic::minnum:
2401 return ConstantFP::get(Ty->getContext(), minnum(Op1V, Op2V));
2402 case Intrinsic::maxnum:
2403 return ConstantFP::get(Ty->getContext(), maxnum(Op1V, Op2V));
2404 case Intrinsic::minimum:
2405 return ConstantFP::get(Ty->getContext(), minimum(Op1V, Op2V));
2406 case Intrinsic::maximum:
2407 return ConstantFP::get(Ty->getContext(), maximum(Op1V, Op2V));
2408 }
2409
2410 if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
2411 return nullptr;
2412
2413 switch (IntrinsicID) {
2414 default:
2415 break;
2416 case Intrinsic::pow:
2417 return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
2418 case Intrinsic::amdgcn_fmul_legacy:
2419 // The legacy behaviour is that multiplying +/- 0.0 by anything, even
2420 // NaN or infinity, gives +0.0.
2421 if (Op1V.isZero() || Op2V.isZero())
2422 return ConstantFP::getNullValue(Ty);
2423 return ConstantFP::get(Ty->getContext(), Op1V * Op2V);
2424 }
2425
2426 if (!TLI)
2427 return nullptr;
2428
2429 LibFunc Func = NotLibFunc;
2430 if (!TLI->getLibFunc(Name, Func))
2431 return nullptr;
2432
2433 switch (Func) {
2434 default:
2435 break;
2436 case LibFunc_pow:
2437 case LibFunc_powf:
2438 case LibFunc_pow_finite:
2439 case LibFunc_powf_finite:
2440 if (TLI->has(Func))
2441 return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
2442 break;
2443 case LibFunc_fmod:
2444 case LibFunc_fmodf:
2445 if (TLI->has(Func)) {
2446 APFloat V = Op1->getValueAPF();
2447 if (APFloat::opStatus::opOK == V.mod(Op2->getValueAPF()))
2448 return ConstantFP::get(Ty->getContext(), V);
2449 }
2450 break;
2451 case LibFunc_remainder:
2452 case LibFunc_remainderf:
2453 if (TLI->has(Func)) {
2454 APFloat V = Op1->getValueAPF();
2455 if (APFloat::opStatus::opOK == V.remainder(Op2->getValueAPF()))
2456 return ConstantFP::get(Ty->getContext(), V);
2457 }
2458 break;
2459 case LibFunc_atan2:
2460 case LibFunc_atan2f:
2461 case LibFunc_atan2_finite:
2462 case LibFunc_atan2f_finite:
2463 if (TLI->has(Func))
2464 return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
2465 break;
2466 }
2467 } else if (auto *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
2468 if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
2469 return nullptr;
2470 if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy())
2471 return ConstantFP::get(
2472 Ty->getContext(),
2473 APFloat((float)std::pow((float)Op1V.convertToDouble(),
2474 (int)Op2C->getZExtValue())));
2475 if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy())
2476 return ConstantFP::get(
2477 Ty->getContext(),
2478 APFloat((float)std::pow((float)Op1V.convertToDouble(),
2479 (int)Op2C->getZExtValue())));
2480 if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy())
2481 return ConstantFP::get(
2482 Ty->getContext(),
2483 APFloat((double)std::pow(Op1V.convertToDouble(),
2484 (int)Op2C->getZExtValue())));
2485
2486 if (IntrinsicID == Intrinsic::amdgcn_ldexp) {
2487 // FIXME: Should flush denorms depending on FP mode, but that's ignored
2488 // everywhere else.
2489
2490 // scalbn is equivalent to ldexp with float radix 2
2491 APFloat Result = scalbn(Op1->getValueAPF(), Op2C->getSExtValue(),
2492 APFloat::rmNearestTiesToEven);
2493 return ConstantFP::get(Ty->getContext(), Result);
2494 }
2495 }
2496 return nullptr;
2497 }
2498
2499 if (Operands[0]->getType()->isIntegerTy() &&
2500 Operands[1]->getType()->isIntegerTy()) {
2501 const APInt *C0, *C1;
2502 if (!getConstIntOrUndef(Operands[0], C0) ||
2503 !getConstIntOrUndef(Operands[1], C1))
2504 return nullptr;
2505
2506 switch (IntrinsicID) {
2507 default: break;
2508 case Intrinsic::smax:
2509 case Intrinsic::smin:
2510 case Intrinsic::umax:
2511 case Intrinsic::umin:
2512 // This is the same as for binary ops - poison propagates.
2513 // TODO: Poison handling should be consolidated.
2514 if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
2515 return PoisonValue::get(Ty);
2516
2517 if (!C0 && !C1)
2518 return UndefValue::get(Ty);
2519 if (!C0 || !C1)
2520 return MinMaxIntrinsic::getSaturationPoint(IntrinsicID, Ty);
2521 return ConstantInt::get(
2522 Ty, ICmpInst::compare(*C0, *C1,
2523 MinMaxIntrinsic::getPredicate(IntrinsicID))
2524 ? *C0
2525 : *C1);
2526
2527 case Intrinsic::usub_with_overflow:
2528 case Intrinsic::ssub_with_overflow:
2529 // X - undef -> { 0, false }
2530 // undef - X -> { 0, false }
2531 if (!C0 || !C1)
2532 return Constant::getNullValue(Ty);
2533 LLVM_FALLTHROUGH[[gnu::fallthrough]];
2534 case Intrinsic::uadd_with_overflow:
2535 case Intrinsic::sadd_with_overflow:
2536 // X + undef -> { -1, false }
2537 // undef + x -> { -1, false }
2538 if (!C0 || !C1) {
2539 return ConstantStruct::get(
2540 cast<StructType>(Ty),
2541 {Constant::getAllOnesValue(Ty->getStructElementType(0)),
2542 Constant::getNullValue(Ty->getStructElementType(1))});
2543 }
2544 LLVM_FALLTHROUGH[[gnu::fallthrough]];
2545 case Intrinsic::smul_with_overflow:
2546 case Intrinsic::umul_with_overflow: {
2547 // undef * X -> { 0, false }
2548 // X * undef -> { 0, false }
2549 if (!C0 || !C1)
2550 return Constant::getNullValue(Ty);
2551
2552 APInt Res;
2553 bool Overflow;
2554 switch (IntrinsicID) {
2555 default: llvm_unreachable("Invalid case")::llvm::llvm_unreachable_internal("Invalid case", "llvm/lib/Analysis/ConstantFolding.cpp"
, 2555)
;
2556 case Intrinsic::sadd_with_overflow:
2557 Res = C0->sadd_ov(*C1, Overflow);
2558 break;
2559 case Intrinsic::uadd_with_overflow:
2560 Res = C0->uadd_ov(*C1, Overflow);
2561 break;
2562 case Intrinsic::ssub_with_overflow:
2563 Res = C0->ssub_ov(*C1, Overflow);
2564 break;
2565 case Intrinsic::usub_with_overflow:
2566 Res = C0->usub_ov(*C1, Overflow);
2567 break;
2568 case Intrinsic::smul_with_overflow:
2569 Res = C0->smul_ov(*C1, Overflow);
2570 break;
2571 case Intrinsic::umul_with_overflow:
2572 Res = C0->umul_ov(*C1, Overflow);
2573 break;
2574 }
2575 Constant *Ops[] = {
2576 ConstantInt::get(Ty->getContext(), Res),
2577 ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
2578 };
2579 return ConstantStruct::get(cast<StructType>(Ty), Ops);
2580 }
2581 case Intrinsic::uadd_sat:
2582 case Intrinsic::sadd_sat:
2583 // This is the same as for binary ops - poison propagates.
2584 // TODO: Poison handling should be consolidated.
2585 if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
2586 return PoisonValue::get(Ty);
2587
2588 if (!C0 && !C1)
2589 return UndefValue::get(Ty);
2590 if (!C0 || !C1)
2591 return Constant::getAllOnesValue(Ty);
2592 if (IntrinsicID == Intrinsic::uadd_sat)
2593 return ConstantInt::get(Ty, C0->uadd_sat(*C1));
2594 else
2595 return ConstantInt::get(Ty, C0->sadd_sat(*C1));
2596 case Intrinsic::usub_sat:
2597 case Intrinsic::ssub_sat:
2598 // This is the same as for binary ops - poison propagates.
2599 // TODO: Poison handling should be consolidated.
2600 if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
2601 return PoisonValue::get(Ty);
2602
2603 if (!C0 && !C1)
2604 return UndefValue::get(Ty);
2605 if (!C0 || !C1)
2606 return Constant::getNullValue(Ty);
2607 if (IntrinsicID == Intrinsic::usub_sat)
2608 return ConstantInt::get(Ty, C0->usub_sat(*C1));
2609 else
2610 return ConstantInt::get(Ty, C0->ssub_sat(*C1));
2611 case Intrinsic::cttz:
2612 case Intrinsic::ctlz:
2613 assert(C1 && "Must be constant int")(static_cast <bool> (C1 && "Must be constant int"
) ? void (0) : __assert_fail ("C1 && \"Must be constant int\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2613, __extension__
__PRETTY_FUNCTION__))
;
2614
2615 // cttz(0, 1) and ctlz(0, 1) are poison.
2616 if (C1->isOne() && (!C0 || C0->isZero()))
2617 return PoisonValue::get(Ty);
2618 if (!C0)
2619 return Constant::getNullValue(Ty);
2620 if (IntrinsicID == Intrinsic::cttz)
2621 return ConstantInt::get(Ty, C0->countTrailingZeros());
2622 else
2623 return ConstantInt::get(Ty, C0->countLeadingZeros());
2624
2625 case Intrinsic::abs:
2626 assert(C1 && "Must be constant int")(static_cast <bool> (C1 && "Must be constant int"
) ? void (0) : __assert_fail ("C1 && \"Must be constant int\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2626, __extension__
__PRETTY_FUNCTION__))
;
2627 assert((C1->isOne() || C1->isZero()) && "Must be 0 or 1")(static_cast <bool> ((C1->isOne() || C1->isZero()
) && "Must be 0 or 1") ? void (0) : __assert_fail ("(C1->isOne() || C1->isZero()) && \"Must be 0 or 1\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2627, __extension__
__PRETTY_FUNCTION__))
;
2628
2629 // Undef or minimum val operand with poison min --> undef
2630 if (C1->isOne() && (!C0 || C0->isMinSignedValue()))
2631 return UndefValue::get(Ty);
2632
2633 // Undef operand with no poison min --> 0 (sign bit must be clear)
2634 if (!C0)
2635 return Constant::getNullValue(Ty);
2636
2637 return ConstantInt::get(Ty, C0->abs());
2638 }
2639
2640 return nullptr;
2641 }
2642
2643 // Support ConstantVector in case we have an Undef in the top.
2644 if ((isa<ConstantVector>(Operands[0]) ||
2645 isa<ConstantDataVector>(Operands[0])) &&
2646 // Check for default rounding mode.
2647 // FIXME: Support other rounding modes?
2648 isa<ConstantInt>(Operands[1]) &&
2649 cast<ConstantInt>(Operands[1])->getValue() == 4) {
2650 auto *Op = cast<Constant>(Operands[0]);
2651 switch (IntrinsicID) {
2652 default: break;
2653 case Intrinsic::x86_avx512_vcvtss2si32:
2654 case Intrinsic::x86_avx512_vcvtss2si64:
2655 case Intrinsic::x86_avx512_vcvtsd2si32:
2656 case Intrinsic::x86_avx512_vcvtsd2si64:
2657 if (ConstantFP *FPOp =
2658 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
2659 return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
2660 /*roundTowardZero=*/false, Ty,
2661 /*IsSigned*/true);
2662 break;
2663 case Intrinsic::x86_avx512_vcvtss2usi32:
2664 case Intrinsic::x86_avx512_vcvtss2usi64:
2665 case Intrinsic::x86_avx512_vcvtsd2usi32:
2666 case Intrinsic::x86_avx512_vcvtsd2usi64:
2667 if (ConstantFP *FPOp =
2668 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
2669 return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
2670 /*roundTowardZero=*/false, Ty,
2671 /*IsSigned*/false);
2672 break;
2673 case Intrinsic::x86_avx512_cvttss2si:
2674 case Intrinsic::x86_avx512_cvttss2si64:
2675 case Intrinsic::x86_avx512_cvttsd2si:
2676 case Intrinsic::x86_avx512_cvttsd2si64:
2677 if (ConstantFP *FPOp =
2678 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
2679 return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
2680 /*roundTowardZero=*/true, Ty,
2681 /*IsSigned*/true);
2682 break;
2683 case Intrinsic::x86_avx512_cvttss2usi:
2684 case Intrinsic::x86_avx512_cvttss2usi64:
2685 case Intrinsic::x86_avx512_cvttsd2usi:
2686 case Intrinsic::x86_avx512_cvttsd2usi64:
2687 if (ConstantFP *FPOp =
2688 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
2689 return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
2690 /*roundTowardZero=*/true, Ty,
2691 /*IsSigned*/false);
2692 break;
2693 }
2694 }
2695 return nullptr;
2696}
2697
2698static APFloat ConstantFoldAMDGCNCubeIntrinsic(Intrinsic::ID IntrinsicID,
2699 const APFloat &S0,
2700 const APFloat &S1,
2701 const APFloat &S2) {
2702 unsigned ID;
2703 const fltSemantics &Sem = S0.getSemantics();
2704 APFloat MA(Sem), SC(Sem), TC(Sem);
2705 if (abs(S2) >= abs(S0) && abs(S2) >= abs(S1)) {
2706 if (S2.isNegative() && S2.isNonZero() && !S2.isNaN()) {
2707 // S2 < 0
2708 ID = 5;
2709 SC = -S0;
2710 } else {
2711 ID = 4;
2712 SC = S0;
2713 }
2714 MA = S2;
2715 TC = -S1;
2716 } else if (abs(S1) >= abs(S0)) {
2717 if (S1.isNegative() && S1.isNonZero() && !S1.isNaN()) {
2718 // S1 < 0
2719 ID = 3;
2720 TC = -S2;
2721 } else {
2722 ID = 2;
2723 TC = S2;
2724 }
2725 MA = S1;
2726 SC = S0;
2727 } else {
2728 if (S0.isNegative() && S0.isNonZero() && !S0.isNaN()) {
2729 // S0 < 0
2730 ID = 1;
2731 SC = S2;
2732 } else {
2733 ID = 0;
2734 SC = -S2;
2735 }
2736 MA = S0;
2737 TC = -S1;
2738 }
2739 switch (IntrinsicID) {
2740 default:
2741 llvm_unreachable("unhandled amdgcn cube intrinsic")::llvm::llvm_unreachable_internal("unhandled amdgcn cube intrinsic"
, "llvm/lib/Analysis/ConstantFolding.cpp", 2741)
;
2742 case Intrinsic::amdgcn_cubeid:
2743 return APFloat(Sem, ID);
2744 case Intrinsic::amdgcn_cubema:
2745 return MA + MA;
2746 case Intrinsic::amdgcn_cubesc:
2747 return SC;
2748 case Intrinsic::amdgcn_cubetc:
2749 return TC;
2750 }
2751}
2752
2753static Constant *ConstantFoldAMDGCNPermIntrinsic(ArrayRef<Constant *> Operands,
2754 Type *Ty) {
2755 const APInt *C0, *C1, *C2;
2756 if (!getConstIntOrUndef(Operands[0], C0) ||
2757 !getConstIntOrUndef(Operands[1], C1) ||
2758 !getConstIntOrUndef(Operands[2], C2))
2759 return nullptr;
2760
2761 if (!C2)
2762 return UndefValue::get(Ty);
2763
2764 APInt Val(32, 0);
2765 unsigned NumUndefBytes = 0;
2766 for (unsigned I = 0; I < 32; I += 8) {
2767 unsigned Sel = C2->extractBitsAsZExtValue(8, I);
2768 unsigned B = 0;
2769
2770 if (Sel >= 13)
2771 B = 0xff;
2772 else if (Sel == 12)
2773 B = 0x00;
2774 else {
2775 const APInt *Src = ((Sel & 10) == 10 || (Sel & 12) == 4) ? C0 : C1;
2776 if (!Src)
2777 ++NumUndefBytes;
2778 else if (Sel < 8)
2779 B = Src->extractBitsAsZExtValue(8, (Sel & 3) * 8);
2780 else
2781 B = Src->extractBitsAsZExtValue(1, (Sel & 1) ? 31 : 15) * 0xff;
2782 }
2783
2784 Val.insertBits(B, I, 8);
2785 }
2786
2787 if (NumUndefBytes == 4)
2788 return UndefValue::get(Ty);
2789
2790 return ConstantInt::get(Ty, Val);
2791}
2792
2793static Constant *ConstantFoldScalarCall3(StringRef Name,
2794 Intrinsic::ID IntrinsicID,
2795 Type *Ty,
2796 ArrayRef<Constant *> Operands,
2797 const TargetLibraryInfo *TLI,
2798 const CallBase *Call) {
2799 assert(Operands.size() == 3 && "Wrong number of operands.")(static_cast <bool> (Operands.size() == 3 && "Wrong number of operands."
) ? void (0) : __assert_fail ("Operands.size() == 3 && \"Wrong number of operands.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2799, __extension__
__PRETTY_FUNCTION__))
;
2800
2801 if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
2802 if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
2803 if (const auto *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
2804 const APFloat &C1 = Op1->getValueAPF();
2805 const APFloat &C2 = Op2->getValueAPF();
2806 const APFloat &C3 = Op3->getValueAPF();
2807
2808 if (const auto *ConstrIntr = dyn_cast<ConstrainedFPIntrinsic>(Call)) {
2809 RoundingMode RM = getEvaluationRoundingMode(ConstrIntr);
2810 APFloat Res = C1;
2811 APFloat::opStatus St;
2812 switch (IntrinsicID) {
2813 default:
2814 return nullptr;
2815 case Intrinsic::experimental_constrained_fma:
2816 case Intrinsic::experimental_constrained_fmuladd:
2817 St = Res.fusedMultiplyAdd(C2, C3, RM);
2818 break;
2819 }
2820 if (mayFoldConstrained(
2821 const_cast<ConstrainedFPIntrinsic *>(ConstrIntr), St))
2822 return ConstantFP::get(Ty->getContext(), Res);
2823 return nullptr;
2824 }
2825
2826 switch (IntrinsicID) {
2827 default: break;
2828 case Intrinsic::amdgcn_fma_legacy: {
2829 // The legacy behaviour is that multiplying +/- 0.0 by anything, even
2830 // NaN or infinity, gives +0.0.
2831 if (C1.isZero() || C2.isZero()) {
2832 // It's tempting to just return C3 here, but that would give the
2833 // wrong result if C3 was -0.0.
2834 return ConstantFP::get(Ty->getContext(), APFloat(0.0f) + C3);
2835 }
2836 LLVM_FALLTHROUGH[[gnu::fallthrough]];
2837 }
2838 case Intrinsic::fma:
2839 case Intrinsic::fmuladd: {
2840 APFloat V = C1;
2841 V.fusedMultiplyAdd(C2, C3, APFloat::rmNearestTiesToEven);
2842 return ConstantFP::get(Ty->getContext(), V);
2843 }
2844 case Intrinsic::amdgcn_cubeid:
2845 case Intrinsic::amdgcn_cubema:
2846 case Intrinsic::amdgcn_cubesc:
2847 case Intrinsic::amdgcn_cubetc: {
2848 APFloat V = ConstantFoldAMDGCNCubeIntrinsic(IntrinsicID, C1, C2, C3);
2849 return ConstantFP::get(Ty->getContext(), V);
2850 }
2851 }
2852 }
2853 }
2854 }
2855
2856 if (IntrinsicID == Intrinsic::smul_fix ||
2857 IntrinsicID == Intrinsic::smul_fix_sat) {
2858 // poison * C -> poison
2859 // C * poison -> poison
2860 if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
2861 return PoisonValue::get(Ty);
2862
2863 const APInt *C0, *C1;
2864 if (!getConstIntOrUndef(Operands[0], C0) ||
2865 !getConstIntOrUndef(Operands[1], C1))
2866 return nullptr;
2867
2868 // undef * C -> 0
2869 // C * undef -> 0
2870 if (!C0 || !C1)
2871 return Constant::getNullValue(Ty);
2872
2873 // This code performs rounding towards negative infinity in case the result
2874 // cannot be represented exactly for the given scale. Targets that do care
2875 // about rounding should use a target hook for specifying how rounding
2876 // should be done, and provide their own folding to be consistent with
2877 // rounding. This is the same approach as used by
2878 // DAGTypeLegalizer::ExpandIntRes_MULFIX.
2879 unsigned Scale = cast<ConstantInt>(Operands[2])->getZExtValue();
2880 unsigned Width = C0->getBitWidth();
2881 assert(Scale < Width && "Illegal scale.")(static_cast <bool> (Scale < Width && "Illegal scale."
) ? void (0) : __assert_fail ("Scale < Width && \"Illegal scale.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2881, __extension__
__PRETTY_FUNCTION__))
;
2882 unsigned ExtendedWidth = Width * 2;
2883 APInt Product = (C0->sextOrSelf(ExtendedWidth) *
2884 C1->sextOrSelf(ExtendedWidth)).ashr(Scale);
2885 if (IntrinsicID == Intrinsic::smul_fix_sat) {
2886 APInt Max = APInt::getSignedMaxValue(Width).sextOrSelf(ExtendedWidth);
2887 APInt Min = APInt::getSignedMinValue(Width).sextOrSelf(ExtendedWidth);
2888 Product = APIntOps::smin(Product, Max);
2889 Product = APIntOps::smax(Product, Min);
2890 }
2891 return ConstantInt::get(Ty->getContext(), Product.sextOrTrunc(Width));
2892 }
2893
2894 if (IntrinsicID == Intrinsic::fshl || IntrinsicID == Intrinsic::fshr) {
2895 const APInt *C0, *C1, *C2;
2896 if (!getConstIntOrUndef(Operands[0], C0) ||
2897 !getConstIntOrUndef(Operands[1], C1) ||
2898 !getConstIntOrUndef(Operands[2], C2))
2899 return nullptr;
2900
2901 bool IsRight = IntrinsicID == Intrinsic::fshr;
2902 if (!C2)
2903 return Operands[IsRight ? 1 : 0];
2904 if (!C0 && !C1)
2905 return UndefValue::get(Ty);
2906
2907 // The shift amount is interpreted as modulo the bitwidth. If the shift
2908 // amount is effectively 0, avoid UB due to oversized inverse shift below.
2909 unsigned BitWidth = C2->getBitWidth();
2910 unsigned ShAmt = C2->urem(BitWidth);
2911 if (!ShAmt)
2912 return Operands[IsRight ? 1 : 0];
2913
2914 // (C0 << ShlAmt) | (C1 >> LshrAmt)
2915 unsigned LshrAmt = IsRight ? ShAmt : BitWidth - ShAmt;
2916 unsigned ShlAmt = !IsRight ? ShAmt : BitWidth - ShAmt;
2917 if (!C0)
2918 return ConstantInt::get(Ty, C1->lshr(LshrAmt));
2919 if (!C1)
2920 return ConstantInt::get(Ty, C0->shl(ShlAmt));
2921 return ConstantInt::get(Ty, C0->shl(ShlAmt) | C1->lshr(LshrAmt));
2922 }
2923
2924 if (IntrinsicID == Intrinsic::amdgcn_perm)
2925 return ConstantFoldAMDGCNPermIntrinsic(Operands, Ty);
2926
2927 return nullptr;
2928}
2929
2930static Constant *ConstantFoldScalarCall(StringRef Name,
2931 Intrinsic::ID IntrinsicID,
2932 Type *Ty,
2933 ArrayRef<Constant *> Operands,
2934 const TargetLibraryInfo *TLI,
2935 const CallBase *Call) {
2936 if (Operands.size() == 1)
2937 return ConstantFoldScalarCall1(Name, IntrinsicID, Ty, Operands, TLI, Call);
2938
2939 if (Operands.size() == 2)
2940 return ConstantFoldScalarCall2(Name, IntrinsicID, Ty, Operands, TLI, Call);
2941
2942 if (Operands.size() == 3)
2943 return ConstantFoldScalarCall3(Name, IntrinsicID, Ty, Operands, TLI, Call);
2944
2945 return nullptr;
2946}
2947
2948static Constant *ConstantFoldFixedVectorCall(
2949 StringRef Name, Intrinsic::ID IntrinsicID, FixedVectorType *FVTy,
2950 ArrayRef<Constant *> Operands, const DataLayout &DL,
2951 const TargetLibraryInfo *TLI, const CallBase *Call) {
2952 SmallVector<Constant *, 4> Result(FVTy->getNumElements());
2953 SmallVector<Constant *, 4> Lane(Operands.size());
2954 Type *Ty = FVTy->getElementType();
2955
2956 switch (IntrinsicID) {
2957 case Intrinsic::masked_load: {
2958 auto *SrcPtr = Operands[0];
2959 auto *Mask = Operands[2];
2960 auto *Passthru = Operands[3];
2961
2962 Constant *VecData = ConstantFoldLoadFromConstPtr(SrcPtr, FVTy, DL);
2963
2964 SmallVector<Constant *, 32> NewElements;
2965 for (unsigned I = 0, E = FVTy->getNumElements(); I != E; ++I) {
2966 auto *MaskElt = Mask->getAggregateElement(I);
2967 if (!MaskElt)
2968 break;
2969 auto *PassthruElt = Passthru->getAggregateElement(I);
2970 auto *VecElt = VecData ? VecData->getAggregateElement(I) : nullptr;
2971 if (isa<UndefValue>(MaskElt)) {
2972 if (PassthruElt)
2973 NewElements.push_back(PassthruElt);
2974 else if (VecElt)
2975 NewElements.push_back(VecElt);
2976 else
2977 return nullptr;
2978 }
2979 if (MaskElt->isNullValue()) {
2980 if (!PassthruElt)
2981 return nullptr;
2982 NewElements.push_back(PassthruElt);
2983 } else if (MaskElt->isOneValue()) {
2984 if (!VecElt)
2985 return nullptr;
2986 NewElements.push_back(VecElt);
2987 } else {
2988 return nullptr;
2989 }
2990 }
2991 if (NewElements.size() != FVTy->getNumElements())
2992 return nullptr;
2993 return ConstantVector::get(NewElements);
2994 }
2995 case Intrinsic::arm_mve_vctp8:
2996 case Intrinsic::arm_mve_vctp16:
2997 case Intrinsic::arm_mve_vctp32:
2998 case Intrinsic::arm_mve_vctp64: {
2999 if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) {
3000 unsigned Lanes = FVTy->getNumElements();
3001 uint64_t Limit = Op->getZExtValue();
3002
3003 SmallVector<Constant *, 16> NCs;
3004 for (unsigned i = 0; i < Lanes; i++) {
3005 if (i < Limit)
3006 NCs.push_back(ConstantInt::getTrue(Ty));
3007 else
3008 NCs.push_back(ConstantInt::getFalse(Ty));
3009 }
3010 return ConstantVector::get(NCs);
3011 }
3012 break;
3013 }
3014 case Intrinsic::get_active_lane_mask: {
3015 auto *Op0 = dyn_cast<ConstantInt>(Operands[0]);
3016 auto *Op1 = dyn_cast<ConstantInt>(Operands[1]);
3017 if (Op0 && Op1) {
3018 unsigned Lanes = FVTy->getNumElements();
3019 uint64_t Base = Op0->getZExtValue();
3020 uint64_t Limit = Op1->getZExtValue();
3021
3022 SmallVector<Constant *, 16> NCs;
3023 for (unsigned i = 0; i < Lanes; i++) {
3024 if (Base + i < Limit)
3025 NCs.push_back(ConstantInt::getTrue(Ty));
3026 else
3027 NCs.push_back(ConstantInt::getFalse(Ty));
3028 }
3029 return ConstantVector::get(NCs);
3030 }
3031 break;
3032 }
3033 default:
3034 break;
3035 }
3036
3037 for (unsigned I = 0, E = FVTy->getNumElements(); I != E; ++I) {
3038 // Gather a column of constants.
3039 for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
3040 // Some intrinsics use a scalar type for certain arguments.
3041 if (hasVectorInstrinsicScalarOpd(IntrinsicID, J)) {
3042 Lane[J] = Operands[J];
3043 continue;
3044 }
3045
3046 Constant *Agg = Operands[J]->getAggregateElement(I);
3047 if (!Agg)
3048 return nullptr;
3049
3050 Lane[J] = Agg;
3051 }
3052
3053 // Use the regular scalar folding to simplify this column.
3054 Constant *Folded =
3055 ConstantFoldScalarCall(Name, IntrinsicID, Ty, Lane, TLI, Call);
3056 if (!Folded)
3057 return nullptr;
3058 Result[I] = Folded;
3059 }
3060
3061 return ConstantVector::get(Result);
3062}
3063
3064static Constant *ConstantFoldScalableVectorCall(
3065 StringRef Name, Intrinsic::ID IntrinsicID, ScalableVectorType *SVTy,
3066 ArrayRef<Constant *> Operands, const DataLayout &DL,
3067 const TargetLibraryInfo *TLI, const CallBase *Call) {
3068 switch (IntrinsicID) {
3069 case Intrinsic::aarch64_sve_convert_from_svbool: {
3070 auto *Src = dyn_cast<Constant>(Operands[0]);
3071 if (!Src || !Src->isNullValue())
3072 break;
3073
3074 return ConstantInt::getFalse(SVTy);
3075 }
3076 default:
3077 break;
3078 }
3079 return nullptr;
3080}
3081
3082} // end anonymous namespace
3083
3084Constant *llvm::ConstantFoldCall(const CallBase *Call, Function *F,
3085 ArrayRef<Constant *> Operands,
3086 const TargetLibraryInfo *TLI) {
3087 if (Call->isNoBuiltin())
3088 return nullptr;
3089 if (!F->hasName())
3090 return nullptr;
3091
3092 // If this is not an intrinsic and not recognized as a library call, bail out.
3093 if (F->getIntrinsicID() == Intrinsic::not_intrinsic) {
3094 if (!TLI)
3095 return nullptr;
3096 LibFunc LibF;
3097 if (!TLI->getLibFunc(*F, LibF))
3098 return nullptr;
3099 }
3100
3101 StringRef Name = F->getName();
3102 Type *Ty = F->getReturnType();
3103 if (auto *FVTy = dyn_cast<FixedVectorType>(Ty))
3104 return ConstantFoldFixedVectorCall(
3105 Name, F->getIntrinsicID(), FVTy, Operands,
3106 F->getParent()->getDataLayout(), TLI, Call);
3107
3108 if (auto *SVTy = dyn_cast<ScalableVectorType>(Ty))
3109 return ConstantFoldScalableVectorCall(
3110 Name, F->getIntrinsicID(), SVTy, Operands,
3111 F->getParent()->getDataLayout(), TLI, Call);
3112
3113 // TODO: If this is a library function, we already discovered that above,
3114 // so we should pass the LibFunc, not the name (and it might be better
3115 // still to separate intrinsic handling from libcalls).
3116 return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI,
3117 Call);
3118}
3119
3120bool llvm::isMathLibCallNoop(const CallBase *Call,
3121 const TargetLibraryInfo *TLI) {
3122 // FIXME: Refactor this code; this duplicates logic in LibCallsShrinkWrap
3123 // (and to some extent ConstantFoldScalarCall).
3124 if (Call->isNoBuiltin() || Call->isStrictFP())
3125 return false;
3126 Function *F = Call->getCalledFunction();
3127 if (!F)
3128 return false;
3129
3130 LibFunc Func;
3131 if (!TLI || !TLI->getLibFunc(*F, Func))
3132 return false;
3133
3134 if (Call->arg_size() == 1) {
3135 if (ConstantFP *OpC = dyn_cast<ConstantFP>(Call->getArgOperand(0))) {
3136 const APFloat &Op = OpC->getValueAPF();
3137 switch (Func) {
3138 case LibFunc_logl:
3139 case LibFunc_log:
3140 case LibFunc_logf:
3141 case LibFunc_log2l:
3142 case LibFunc_log2:
3143 case LibFunc_log2f:
3144 case LibFunc_log10l:
3145 case LibFunc_log10:
3146 case LibFunc_log10f:
3147 return Op.isNaN() || (!Op.isZero() && !Op.isNegative());
3148
3149 case LibFunc_expl:
3150 case LibFunc_exp:
3151 case LibFunc_expf:
3152 // FIXME: These boundaries are slightly conservative.
3153 if (OpC->getType()->isDoubleTy())
3154 return !(Op < APFloat(-745.0) || Op > APFloat(709.0));
3155 if (OpC->getType()->isFloatTy())
3156 return !(Op < APFloat(-103.0f) || Op > APFloat(88.0f));
3157 break;
3158
3159 case LibFunc_exp2l:
3160 case LibFunc_exp2:
3161 case LibFunc_exp2f:
3162 // FIXME: These boundaries are slightly conservative.
3163 if (OpC->getType()->isDoubleTy())
3164 return !(Op < APFloat(-1074.0) || Op > APFloat(1023.0));
3165 if (OpC->getType()->isFloatTy())
3166 return !(Op < APFloat(-149.0f) || Op > APFloat(127.0f));
3167 break;
3168
3169 case LibFunc_sinl:
3170 case LibFunc_sin:
3171 case LibFunc_sinf:
3172 case LibFunc_cosl:
3173 case LibFunc_cos:
3174 case LibFunc_cosf:
3175 return !Op.isInfinity();
3176
3177 case LibFunc_tanl:
3178 case LibFunc_tan:
3179 case LibFunc_tanf: {
3180 // FIXME: Stop using the host math library.
3181 // FIXME: The computation isn't done in the right precision.
3182 Type *Ty = OpC->getType();
3183 if (Ty->isDoubleTy() || Ty->isFloatTy() || Ty->isHalfTy())
3184 return ConstantFoldFP(tan, OpC->getValueAPF(), Ty) != nullptr;
3185 break;
3186 }
3187
3188 case LibFunc_asinl:
3189 case LibFunc_asin:
3190 case LibFunc_asinf:
3191 case LibFunc_acosl:
3192 case LibFunc_acos:
3193 case LibFunc_acosf:
3194 return !(Op < APFloat(Op.getSemantics(), "-1") ||
3195 Op > APFloat(Op.getSemantics(), "1"));
3196
3197 case LibFunc_sinh:
3198 case LibFunc_cosh:
3199 case LibFunc_sinhf:
3200 case LibFunc_coshf:
3201 case LibFunc_sinhl:
3202 case LibFunc_coshl:
3203 // FIXME: These boundaries are slightly conservative.
3204 if (OpC->getType()->isDoubleTy())
3205 return !(Op < APFloat(-710.0) || Op > APFloat(710.0));
3206 if (OpC->getType()->isFloatTy())
3207 return !(Op < APFloat(-89.0f) || Op > APFloat(89.0f));
3208 break;
3209
3210 case LibFunc_sqrtl:
3211 case LibFunc_sqrt:
3212 case LibFunc_sqrtf:
3213 return Op.isNaN() || Op.isZero() || !Op.isNegative();
3214
3215 // FIXME: Add more functions: sqrt_finite, atanh, expm1, log1p,
3216 // maybe others?
3217 default:
3218 break;
3219 }
3220 }
3221 }
3222
3223 if (Call->arg_size() == 2) {
3224 ConstantFP *Op0C = dyn_cast<ConstantFP>(Call->getArgOperand(0));
3225 ConstantFP *Op1C = dyn_cast<ConstantFP>(Call->getArgOperand(1));
3226 if (Op0C && Op1C) {
3227 const APFloat &Op0 = Op0C->getValueAPF();
3228 const APFloat &Op1 = Op1C->getValueAPF();
3229
3230 switch (Func) {
3231 case LibFunc_powl:
3232 case LibFunc_pow:
3233 case LibFunc_powf: {
3234 // FIXME: Stop using the host math library.
3235 // FIXME: The computation isn't done in the right precision.
3236 Type *Ty = Op0C->getType();
3237 if (Ty->isDoubleTy() || Ty->isFloatTy() || Ty->isHalfTy()) {
3238 if (Ty == Op1C->getType())
3239 return ConstantFoldBinaryFP(pow, Op0, Op1, Ty) != nullptr;
3240 }
3241 break;
3242 }
3243
3244 case LibFunc_fmodl:
3245 case LibFunc_fmod:
3246 case LibFunc_fmodf:
3247 case LibFunc_remainderl:
3248 case LibFunc_remainder:
3249 case LibFunc_remainderf:
3250 return Op0.isNaN() || Op1.isNaN() ||
3251 (!Op0.isInfinity() && !Op1.isZero());
3252
3253 default:
3254 break;
3255 }
3256 }
3257 }
3258
3259 return false;
3260}
3261
3262void TargetFolder::anchor() {}