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InferAddressSpaces.cpp
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1 //===- InferAddressSpace.cpp - --------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // CUDA C/C++ includes memory space designation as variable type qualifers (such
11 // as __global__ and __shared__). Knowing the space of a memory access allows
12 // CUDA compilers to emit faster PTX loads and stores. For example, a load from
13 // shared memory can be translated to `ld.shared` which is roughly 10% faster
14 // than a generic `ld` on an NVIDIA Tesla K40c.
15 //
16 // Unfortunately, type qualifiers only apply to variable declarations, so CUDA
17 // compilers must infer the memory space of an address expression from
18 // type-qualified variables.
19 //
20 // LLVM IR uses non-zero (so-called) specific address spaces to represent memory
21 // spaces (e.g. addrspace(3) means shared memory). The Clang frontend
22 // places only type-qualified variables in specific address spaces, and then
23 // conservatively `addrspacecast`s each type-qualified variable to addrspace(0)
24 // (so-called the generic address space) for other instructions to use.
25 //
26 // For example, the Clang translates the following CUDA code
27 // __shared__ float a[10];
28 // float v = a[i];
29 // to
30 // %0 = addrspacecast [10 x float] addrspace(3)* @a to [10 x float]*
31 // %1 = gep [10 x float], [10 x float]* %0, i64 0, i64 %i
32 // %v = load float, float* %1 ; emits ld.f32
33 // @a is in addrspace(3) since it's type-qualified, but its use from %1 is
34 // redirected to %0 (the generic version of @a).
35 //
36 // The optimization implemented in this file propagates specific address spaces
37 // from type-qualified variable declarations to its users. For example, it
38 // optimizes the above IR to
39 // %1 = gep [10 x float] addrspace(3)* @a, i64 0, i64 %i
40 // %v = load float addrspace(3)* %1 ; emits ld.shared.f32
41 // propagating the addrspace(3) from @a to %1. As the result, the NVPTX
42 // codegen is able to emit ld.shared.f32 for %v.
43 //
44 // Address space inference works in two steps. First, it uses a data-flow
45 // analysis to infer as many generic pointers as possible to point to only one
46 // specific address space. In the above example, it can prove that %1 only
47 // points to addrspace(3). This algorithm was published in
48 // CUDA: Compiling and optimizing for a GPU platform
49 // Chakrabarti, Grover, Aarts, Kong, Kudlur, Lin, Marathe, Murphy, Wang
50 // ICCS 2012
51 //
52 // Then, address space inference replaces all refinable generic pointers with
53 // equivalent specific pointers.
54 //
55 // The major challenge of implementing this optimization is handling PHINodes,
56 // which may create loops in the data flow graph. This brings two complications.
57 //
58 // First, the data flow analysis in Step 1 needs to be circular. For example,
59 // %generic.input = addrspacecast float addrspace(3)* %input to float*
60 // loop:
61 // %y = phi [ %generic.input, %y2 ]
62 // %y2 = getelementptr %y, 1
63 // %v = load %y2
64 // br ..., label %loop, ...
65 // proving %y specific requires proving both %generic.input and %y2 specific,
66 // but proving %y2 specific circles back to %y. To address this complication,
67 // the data flow analysis operates on a lattice:
68 // uninitialized > specific address spaces > generic.
69 // All address expressions (our implementation only considers phi, bitcast,
70 // addrspacecast, and getelementptr) start with the uninitialized address space.
71 // The monotone transfer function moves the address space of a pointer down a
72 // lattice path from uninitialized to specific and then to generic. A join
73 // operation of two different specific address spaces pushes the expression down
74 // to the generic address space. The analysis completes once it reaches a fixed
75 // point.
76 //
77 // Second, IR rewriting in Step 2 also needs to be circular. For example,
78 // converting %y to addrspace(3) requires the compiler to know the converted
79 // %y2, but converting %y2 needs the converted %y. To address this complication,
80 // we break these cycles using "undef" placeholders. When converting an
81 // instruction `I` to a new address space, if its operand `Op` is not converted
82 // yet, we let `I` temporarily use `undef` and fix all the uses of undef later.
83 // For instance, our algorithm first converts %y to
84 // %y' = phi float addrspace(3)* [ %input, undef ]
85 // Then, it converts %y2 to
86 // %y2' = getelementptr %y', 1
87 // Finally, it fixes the undef in %y' so that
88 // %y' = phi float addrspace(3)* [ %input, %y2' ]
89 //
90 //===----------------------------------------------------------------------===//
91 
92 #include "llvm/ADT/ArrayRef.h"
93 #include "llvm/ADT/DenseMap.h"
94 #include "llvm/ADT/DenseSet.h"
95 #include "llvm/ADT/None.h"
96 #include "llvm/ADT/Optional.h"
97 #include "llvm/ADT/SetVector.h"
98 #include "llvm/ADT/SmallVector.h"
101 #include "llvm/IR/BasicBlock.h"
102 #include "llvm/IR/Constant.h"
103 #include "llvm/IR/Constants.h"
104 #include "llvm/IR/Function.h"
105 #include "llvm/IR/IRBuilder.h"
106 #include "llvm/IR/InstIterator.h"
107 #include "llvm/IR/Instruction.h"
108 #include "llvm/IR/Instructions.h"
109 #include "llvm/IR/IntrinsicInst.h"
110 #include "llvm/IR/Intrinsics.h"
111 #include "llvm/IR/LLVMContext.h"
112 #include "llvm/IR/Operator.h"
113 #include "llvm/IR/Type.h"
114 #include "llvm/IR/Use.h"
115 #include "llvm/IR/User.h"
116 #include "llvm/IR/Value.h"
117 #include "llvm/IR/ValueHandle.h"
118 #include "llvm/Pass.h"
119 #include "llvm/Support/Casting.h"
120 #include "llvm/Support/Compiler.h"
121 #include "llvm/Support/Debug.h"
124 #include "llvm/Transforms/Scalar.h"
126 #include <cassert>
127 #include <iterator>
128 #include <limits>
129 #include <utility>
130 #include <vector>
131 
132 #define DEBUG_TYPE "infer-address-spaces"
133 
134 using namespace llvm;
135 
136 static const unsigned UninitializedAddressSpace =
138 
139 namespace {
140 
141 using ValueToAddrSpaceMapTy = DenseMap<const Value *, unsigned>;
142 
143 /// InferAddressSpaces
144 class InferAddressSpaces : public FunctionPass {
145  /// Target specific address space which uses of should be replaced if
146  /// possible.
147  unsigned FlatAddrSpace;
148 
149 public:
150  static char ID;
151 
152  InferAddressSpaces() : FunctionPass(ID) {}
153 
154  void getAnalysisUsage(AnalysisUsage &AU) const override {
155  AU.setPreservesCFG();
157  }
158 
159  bool runOnFunction(Function &F) override;
160 
161 private:
162  // Returns the new address space of V if updated; otherwise, returns None.
164  updateAddressSpace(const Value &V,
165  const ValueToAddrSpaceMapTy &InferredAddrSpace) const;
166 
167  // Tries to infer the specific address space of each address expression in
168  // Postorder.
169  void inferAddressSpaces(ArrayRef<WeakTrackingVH> Postorder,
170  ValueToAddrSpaceMapTy *InferredAddrSpace) const;
171 
172  bool isSafeToCastConstAddrSpace(Constant *C, unsigned NewAS) const;
173 
174  // Changes the flat address expressions in function F to point to specific
175  // address spaces if InferredAddrSpace says so. Postorder is the postorder of
176  // all flat expressions in the use-def graph of function F.
177  bool rewriteWithNewAddressSpaces(
178  const TargetTransformInfo &TTI, ArrayRef<WeakTrackingVH> Postorder,
179  const ValueToAddrSpaceMapTy &InferredAddrSpace, Function *F) const;
180 
181  void appendsFlatAddressExpressionToPostorderStack(
182  Value *V, std::vector<std::pair<Value *, bool>> &PostorderStack,
183  DenseSet<Value *> &Visited) const;
184 
185  bool rewriteIntrinsicOperands(IntrinsicInst *II,
186  Value *OldV, Value *NewV) const;
187  void collectRewritableIntrinsicOperands(
188  IntrinsicInst *II,
189  std::vector<std::pair<Value *, bool>> &PostorderStack,
190  DenseSet<Value *> &Visited) const;
191 
192  std::vector<WeakTrackingVH> collectFlatAddressExpressions(Function &F) const;
193 
194  Value *cloneValueWithNewAddressSpace(
195  Value *V, unsigned NewAddrSpace,
196  const ValueToValueMapTy &ValueWithNewAddrSpace,
197  SmallVectorImpl<const Use *> *UndefUsesToFix) const;
198  unsigned joinAddressSpaces(unsigned AS1, unsigned AS2) const;
199 };
200 
201 } // end anonymous namespace
202 
203 char InferAddressSpaces::ID = 0;
204 
205 namespace llvm {
206 
208 
209 } // end namespace llvm
210 
211 INITIALIZE_PASS(InferAddressSpaces, DEBUG_TYPE, "Infer address spaces",
212  false, false)
213 
214 // Returns true if V is an address expression.
215 // TODO: Currently, we consider only phi, bitcast, addrspacecast, and
216 // getelementptr operators.
217 static bool isAddressExpression(const Value &V) {
218  if (!isa<Operator>(V))
219  return false;
220 
221  switch (cast<Operator>(V).getOpcode()) {
222  case Instruction::PHI:
223  case Instruction::BitCast:
224  case Instruction::AddrSpaceCast:
225  case Instruction::GetElementPtr:
226  case Instruction::Select:
227  return true;
228  default:
229  return false;
230  }
231 }
232 
233 // Returns the pointer operands of V.
234 //
235 // Precondition: V is an address expression.
237  const Operator &Op = cast<Operator>(V);
238  switch (Op.getOpcode()) {
239  case Instruction::PHI: {
240  auto IncomingValues = cast<PHINode>(Op).incoming_values();
241  return SmallVector<Value *, 2>(IncomingValues.begin(),
242  IncomingValues.end());
243  }
244  case Instruction::BitCast:
245  case Instruction::AddrSpaceCast:
246  case Instruction::GetElementPtr:
247  return {Op.getOperand(0)};
248  case Instruction::Select:
249  return {Op.getOperand(1), Op.getOperand(2)};
250  default:
251  llvm_unreachable("Unexpected instruction type.");
252  }
253 }
254 
255 // TODO: Move logic to TTI?
256 bool InferAddressSpaces::rewriteIntrinsicOperands(IntrinsicInst *II,
257  Value *OldV,
258  Value *NewV) const {
259  Module *M = II->getParent()->getParent()->getParent();
260 
261  switch (II->getIntrinsicID()) {
262  case Intrinsic::amdgcn_atomic_inc:
263  case Intrinsic::amdgcn_atomic_dec:
264  case Intrinsic::amdgcn_ds_fadd:
265  case Intrinsic::amdgcn_ds_fmin:
266  case Intrinsic::amdgcn_ds_fmax: {
268  if (!IsVolatile || !IsVolatile->isZero())
269  return false;
270 
272  }
273  case Intrinsic::objectsize: {
274  Type *DestTy = II->getType();
275  Type *SrcTy = NewV->getType();
276  Function *NewDecl =
277  Intrinsic::getDeclaration(M, II->getIntrinsicID(), {DestTy, SrcTy});
278  II->setArgOperand(0, NewV);
279  II->setCalledFunction(NewDecl);
280  return true;
281  }
282  default:
283  return false;
284  }
285 }
286 
287 // TODO: Move logic to TTI?
288 void InferAddressSpaces::collectRewritableIntrinsicOperands(
289  IntrinsicInst *II, std::vector<std::pair<Value *, bool>> &PostorderStack,
290  DenseSet<Value *> &Visited) const {
291  switch (II->getIntrinsicID()) {
292  case Intrinsic::objectsize:
293  case Intrinsic::amdgcn_atomic_inc:
294  case Intrinsic::amdgcn_atomic_dec:
295  case Intrinsic::amdgcn_ds_fadd:
296  case Intrinsic::amdgcn_ds_fmin:
297  case Intrinsic::amdgcn_ds_fmax:
298  appendsFlatAddressExpressionToPostorderStack(II->getArgOperand(0),
299  PostorderStack, Visited);
300  break;
301  default:
302  break;
303  }
304 }
305 
306 // Returns all flat address expressions in function F. The elements are
307 // If V is an unvisited flat address expression, appends V to PostorderStack
308 // and marks it as visited.
309 void InferAddressSpaces::appendsFlatAddressExpressionToPostorderStack(
310  Value *V, std::vector<std::pair<Value *, bool>> &PostorderStack,
311  DenseSet<Value *> &Visited) const {
312  assert(V->getType()->isPointerTy());
313 
314  // Generic addressing expressions may be hidden in nested constant
315  // expressions.
316  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
317  // TODO: Look in non-address parts, like icmp operands.
318  if (isAddressExpression(*CE) && Visited.insert(CE).second)
319  PostorderStack.push_back(std::make_pair(CE, false));
320 
321  return;
322  }
323 
324  if (isAddressExpression(*V) &&
325  V->getType()->getPointerAddressSpace() == FlatAddrSpace) {
326  if (Visited.insert(V).second) {
327  PostorderStack.push_back(std::make_pair(V, false));
328 
329  Operator *Op = cast<Operator>(V);
330  for (unsigned I = 0, E = Op->getNumOperands(); I != E; ++I) {
331  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op->getOperand(I))) {
332  if (isAddressExpression(*CE) && Visited.insert(CE).second)
333  PostorderStack.emplace_back(CE, false);
334  }
335  }
336  }
337  }
338 }
339 
340 // Returns all flat address expressions in function F. The elements are ordered
341 // ordered in postorder.
342 std::vector<WeakTrackingVH>
343 InferAddressSpaces::collectFlatAddressExpressions(Function &F) const {
344  // This function implements a non-recursive postorder traversal of a partial
345  // use-def graph of function F.
346  std::vector<std::pair<Value *, bool>> PostorderStack;
347  // The set of visited expressions.
348  DenseSet<Value *> Visited;
349 
350  auto PushPtrOperand = [&](Value *Ptr) {
351  appendsFlatAddressExpressionToPostorderStack(Ptr, PostorderStack,
352  Visited);
353  };
354 
355  // Look at operations that may be interesting accelerate by moving to a known
356  // address space. We aim at generating after loads and stores, but pure
357  // addressing calculations may also be faster.
358  for (Instruction &I : instructions(F)) {
359  if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {
360  if (!GEP->getType()->isVectorTy())
361  PushPtrOperand(GEP->getPointerOperand());
362  } else if (auto *LI = dyn_cast<LoadInst>(&I))
363  PushPtrOperand(LI->getPointerOperand());
364  else if (auto *SI = dyn_cast<StoreInst>(&I))
365  PushPtrOperand(SI->getPointerOperand());
366  else if (auto *RMW = dyn_cast<AtomicRMWInst>(&I))
367  PushPtrOperand(RMW->getPointerOperand());
368  else if (auto *CmpX = dyn_cast<AtomicCmpXchgInst>(&I))
369  PushPtrOperand(CmpX->getPointerOperand());
370  else if (auto *MI = dyn_cast<MemIntrinsic>(&I)) {
371  // For memset/memcpy/memmove, any pointer operand can be replaced.
372  PushPtrOperand(MI->getRawDest());
373 
374  // Handle 2nd operand for memcpy/memmove.
375  if (auto *MTI = dyn_cast<MemTransferInst>(MI))
376  PushPtrOperand(MTI->getRawSource());
377  } else if (auto *II = dyn_cast<IntrinsicInst>(&I))
378  collectRewritableIntrinsicOperands(II, PostorderStack, Visited);
379  else if (ICmpInst *Cmp = dyn_cast<ICmpInst>(&I)) {
380  // FIXME: Handle vectors of pointers
381  if (Cmp->getOperand(0)->getType()->isPointerTy()) {
382  PushPtrOperand(Cmp->getOperand(0));
383  PushPtrOperand(Cmp->getOperand(1));
384  }
385  } else if (auto *ASC = dyn_cast<AddrSpaceCastInst>(&I)) {
386  if (!ASC->getType()->isVectorTy())
387  PushPtrOperand(ASC->getPointerOperand());
388  }
389  }
390 
391  std::vector<WeakTrackingVH> Postorder; // The resultant postorder.
392  while (!PostorderStack.empty()) {
393  Value *TopVal = PostorderStack.back().first;
394  // If the operands of the expression on the top are already explored,
395  // adds that expression to the resultant postorder.
396  if (PostorderStack.back().second) {
397  if (TopVal->getType()->getPointerAddressSpace() == FlatAddrSpace)
398  Postorder.push_back(TopVal);
399  PostorderStack.pop_back();
400  continue;
401  }
402  // Otherwise, adds its operands to the stack and explores them.
403  PostorderStack.back().second = true;
404  for (Value *PtrOperand : getPointerOperands(*TopVal)) {
405  appendsFlatAddressExpressionToPostorderStack(PtrOperand, PostorderStack,
406  Visited);
407  }
408  }
409  return Postorder;
410 }
411 
412 // A helper function for cloneInstructionWithNewAddressSpace. Returns the clone
413 // of OperandUse.get() in the new address space. If the clone is not ready yet,
414 // returns an undef in the new address space as a placeholder.
416  const Use &OperandUse, unsigned NewAddrSpace,
417  const ValueToValueMapTy &ValueWithNewAddrSpace,
418  SmallVectorImpl<const Use *> *UndefUsesToFix) {
419  Value *Operand = OperandUse.get();
420 
421  Type *NewPtrTy =
422  Operand->getType()->getPointerElementType()->getPointerTo(NewAddrSpace);
423 
424  if (Constant *C = dyn_cast<Constant>(Operand))
425  return ConstantExpr::getAddrSpaceCast(C, NewPtrTy);
426 
427  if (Value *NewOperand = ValueWithNewAddrSpace.lookup(Operand))
428  return NewOperand;
429 
430  UndefUsesToFix->push_back(&OperandUse);
431  return UndefValue::get(NewPtrTy);
432 }
433 
434 // Returns a clone of `I` with its operands converted to those specified in
435 // ValueWithNewAddrSpace. Due to potential cycles in the data flow graph, an
436 // operand whose address space needs to be modified might not exist in
437 // ValueWithNewAddrSpace. In that case, uses undef as a placeholder operand and
438 // adds that operand use to UndefUsesToFix so that caller can fix them later.
439 //
440 // Note that we do not necessarily clone `I`, e.g., if it is an addrspacecast
441 // from a pointer whose type already matches. Therefore, this function returns a
442 // Value* instead of an Instruction*.
444  Instruction *I, unsigned NewAddrSpace,
445  const ValueToValueMapTy &ValueWithNewAddrSpace,
446  SmallVectorImpl<const Use *> *UndefUsesToFix) {
447  Type *NewPtrType =
448  I->getType()->getPointerElementType()->getPointerTo(NewAddrSpace);
449 
450  if (I->getOpcode() == Instruction::AddrSpaceCast) {
451  Value *Src = I->getOperand(0);
452  // Because `I` is flat, the source address space must be specific.
453  // Therefore, the inferred address space must be the source space, according
454  // to our algorithm.
455  assert(Src->getType()->getPointerAddressSpace() == NewAddrSpace);
456  if (Src->getType() != NewPtrType)
457  return new BitCastInst(Src, NewPtrType);
458  return Src;
459  }
460 
461  // Computes the converted pointer operands.
462  SmallVector<Value *, 4> NewPointerOperands;
463  for (const Use &OperandUse : I->operands()) {
464  if (!OperandUse.get()->getType()->isPointerTy())
465  NewPointerOperands.push_back(nullptr);
466  else
468  OperandUse, NewAddrSpace, ValueWithNewAddrSpace, UndefUsesToFix));
469  }
470 
471  switch (I->getOpcode()) {
472  case Instruction::BitCast:
473  return new BitCastInst(NewPointerOperands[0], NewPtrType);
474  case Instruction::PHI: {
475  assert(I->getType()->isPointerTy());
476  PHINode *PHI = cast<PHINode>(I);
477  PHINode *NewPHI = PHINode::Create(NewPtrType, PHI->getNumIncomingValues());
478  for (unsigned Index = 0; Index < PHI->getNumIncomingValues(); ++Index) {
479  unsigned OperandNo = PHINode::getOperandNumForIncomingValue(Index);
480  NewPHI->addIncoming(NewPointerOperands[OperandNo],
481  PHI->getIncomingBlock(Index));
482  }
483  return NewPHI;
484  }
485  case Instruction::GetElementPtr: {
486  GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
488  GEP->getSourceElementType(), NewPointerOperands[0],
489  SmallVector<Value *, 4>(GEP->idx_begin(), GEP->idx_end()));
490  NewGEP->setIsInBounds(GEP->isInBounds());
491  return NewGEP;
492  }
493  case Instruction::Select:
494  assert(I->getType()->isPointerTy());
495  return SelectInst::Create(I->getOperand(0), NewPointerOperands[1],
496  NewPointerOperands[2], "", nullptr, I);
497  default:
498  llvm_unreachable("Unexpected opcode");
499  }
500 }
501 
502 // Similar to cloneInstructionWithNewAddressSpace, returns a clone of the
503 // constant expression `CE` with its operands replaced as specified in
504 // ValueWithNewAddrSpace.
506  ConstantExpr *CE, unsigned NewAddrSpace,
507  const ValueToValueMapTy &ValueWithNewAddrSpace) {
508  Type *TargetType =
509  CE->getType()->getPointerElementType()->getPointerTo(NewAddrSpace);
510 
511  if (CE->getOpcode() == Instruction::AddrSpaceCast) {
512  // Because CE is flat, the source address space must be specific.
513  // Therefore, the inferred address space must be the source space according
514  // to our algorithm.
516  NewAddrSpace);
517  return ConstantExpr::getBitCast(CE->getOperand(0), TargetType);
518  }
519 
520  if (CE->getOpcode() == Instruction::BitCast) {
521  if (Value *NewOperand = ValueWithNewAddrSpace.lookup(CE->getOperand(0)))
522  return ConstantExpr::getBitCast(cast<Constant>(NewOperand), TargetType);
523  return ConstantExpr::getAddrSpaceCast(CE, TargetType);
524  }
525 
526  if (CE->getOpcode() == Instruction::Select) {
527  Constant *Src0 = CE->getOperand(1);
528  Constant *Src1 = CE->getOperand(2);
529  if (Src0->getType()->getPointerAddressSpace() ==
530  Src1->getType()->getPointerAddressSpace()) {
531 
533  CE->getOperand(0), ConstantExpr::getAddrSpaceCast(Src0, TargetType),
534  ConstantExpr::getAddrSpaceCast(Src1, TargetType));
535  }
536  }
537 
538  // Computes the operands of the new constant expression.
539  bool IsNew = false;
540  SmallVector<Constant *, 4> NewOperands;
541  for (unsigned Index = 0; Index < CE->getNumOperands(); ++Index) {
542  Constant *Operand = CE->getOperand(Index);
543  // If the address space of `Operand` needs to be modified, the new operand
544  // with the new address space should already be in ValueWithNewAddrSpace
545  // because (1) the constant expressions we consider (i.e. addrspacecast,
546  // bitcast, and getelementptr) do not incur cycles in the data flow graph
547  // and (2) this function is called on constant expressions in postorder.
548  if (Value *NewOperand = ValueWithNewAddrSpace.lookup(Operand)) {
549  IsNew = true;
550  NewOperands.push_back(cast<Constant>(NewOperand));
551  } else {
552  // Otherwise, reuses the old operand.
553  NewOperands.push_back(Operand);
554  }
555  }
556 
557  // If !IsNew, we will replace the Value with itself. However, replaced values
558  // are assumed to wrapped in a addrspace cast later so drop it now.
559  if (!IsNew)
560  return nullptr;
561 
562  if (CE->getOpcode() == Instruction::GetElementPtr) {
563  // Needs to specify the source type while constructing a getelementptr
564  // constant expression.
565  return CE->getWithOperands(
566  NewOperands, TargetType, /*OnlyIfReduced=*/false,
567  NewOperands[0]->getType()->getPointerElementType());
568  }
569 
570  return CE->getWithOperands(NewOperands, TargetType);
571 }
572 
573 // Returns a clone of the value `V`, with its operands replaced as specified in
574 // ValueWithNewAddrSpace. This function is called on every flat address
575 // expression whose address space needs to be modified, in postorder.
576 //
577 // See cloneInstructionWithNewAddressSpace for the meaning of UndefUsesToFix.
578 Value *InferAddressSpaces::cloneValueWithNewAddressSpace(
579  Value *V, unsigned NewAddrSpace,
580  const ValueToValueMapTy &ValueWithNewAddrSpace,
581  SmallVectorImpl<const Use *> *UndefUsesToFix) const {
582  // All values in Postorder are flat address expressions.
583  assert(isAddressExpression(*V) &&
584  V->getType()->getPointerAddressSpace() == FlatAddrSpace);
585 
586  if (Instruction *I = dyn_cast<Instruction>(V)) {
588  I, NewAddrSpace, ValueWithNewAddrSpace, UndefUsesToFix);
589  if (Instruction *NewI = dyn_cast<Instruction>(NewV)) {
590  if (NewI->getParent() == nullptr) {
591  NewI->insertBefore(I);
592  NewI->takeName(I);
593  }
594  }
595  return NewV;
596  }
597 
599  cast<ConstantExpr>(V), NewAddrSpace, ValueWithNewAddrSpace);
600 }
601 
602 // Defines the join operation on the address space lattice (see the file header
603 // comments).
604 unsigned InferAddressSpaces::joinAddressSpaces(unsigned AS1,
605  unsigned AS2) const {
606  if (AS1 == FlatAddrSpace || AS2 == FlatAddrSpace)
607  return FlatAddrSpace;
608 
609  if (AS1 == UninitializedAddressSpace)
610  return AS2;
611  if (AS2 == UninitializedAddressSpace)
612  return AS1;
613 
614  // The join of two different specific address spaces is flat.
615  return (AS1 == AS2) ? AS1 : FlatAddrSpace;
616 }
617 
619  if (skipFunction(F))
620  return false;
621 
622  const TargetTransformInfo &TTI =
623  getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
624  FlatAddrSpace = TTI.getFlatAddressSpace();
625  if (FlatAddrSpace == UninitializedAddressSpace)
626  return false;
627 
628  // Collects all flat address expressions in postorder.
629  std::vector<WeakTrackingVH> Postorder = collectFlatAddressExpressions(F);
630 
631  // Runs a data-flow analysis to refine the address spaces of every expression
632  // in Postorder.
633  ValueToAddrSpaceMapTy InferredAddrSpace;
634  inferAddressSpaces(Postorder, &InferredAddrSpace);
635 
636  // Changes the address spaces of the flat address expressions who are inferred
637  // to point to a specific address space.
638  return rewriteWithNewAddressSpaces(TTI, Postorder, InferredAddrSpace, &F);
639 }
640 
641 // Constants need to be tracked through RAUW to handle cases with nested
642 // constant expressions, so wrap values in WeakTrackingVH.
643 void InferAddressSpaces::inferAddressSpaces(
644  ArrayRef<WeakTrackingVH> Postorder,
645  ValueToAddrSpaceMapTy *InferredAddrSpace) const {
646  SetVector<Value *> Worklist(Postorder.begin(), Postorder.end());
647  // Initially, all expressions are in the uninitialized address space.
648  for (Value *V : Postorder)
649  (*InferredAddrSpace)[V] = UninitializedAddressSpace;
650 
651  while (!Worklist.empty()) {
652  Value *V = Worklist.pop_back_val();
653 
654  // Tries to update the address space of the stack top according to the
655  // address spaces of its operands.
656  LLVM_DEBUG(dbgs() << "Updating the address space of\n " << *V << '\n');
657  Optional<unsigned> NewAS = updateAddressSpace(*V, *InferredAddrSpace);
658  if (!NewAS.hasValue())
659  continue;
660  // If any updates are made, grabs its users to the worklist because
661  // their address spaces can also be possibly updated.
662  LLVM_DEBUG(dbgs() << " to " << NewAS.getValue() << '\n');
663  (*InferredAddrSpace)[V] = NewAS.getValue();
664 
665  for (Value *User : V->users()) {
666  // Skip if User is already in the worklist.
667  if (Worklist.count(User))
668  continue;
669 
670  auto Pos = InferredAddrSpace->find(User);
671  // Our algorithm only updates the address spaces of flat address
672  // expressions, which are those in InferredAddrSpace.
673  if (Pos == InferredAddrSpace->end())
674  continue;
675 
676  // Function updateAddressSpace moves the address space down a lattice
677  // path. Therefore, nothing to do if User is already inferred as flat (the
678  // bottom element in the lattice).
679  if (Pos->second == FlatAddrSpace)
680  continue;
681 
682  Worklist.insert(User);
683  }
684  }
685 }
686 
687 Optional<unsigned> InferAddressSpaces::updateAddressSpace(
688  const Value &V, const ValueToAddrSpaceMapTy &InferredAddrSpace) const {
689  assert(InferredAddrSpace.count(&V));
690 
691  // The new inferred address space equals the join of the address spaces
692  // of all its pointer operands.
693  unsigned NewAS = UninitializedAddressSpace;
694 
695  const Operator &Op = cast<Operator>(V);
696  if (Op.getOpcode() == Instruction::Select) {
697  Value *Src0 = Op.getOperand(1);
698  Value *Src1 = Op.getOperand(2);
699 
700  auto I = InferredAddrSpace.find(Src0);
701  unsigned Src0AS = (I != InferredAddrSpace.end()) ?
702  I->second : Src0->getType()->getPointerAddressSpace();
703 
704  auto J = InferredAddrSpace.find(Src1);
705  unsigned Src1AS = (J != InferredAddrSpace.end()) ?
706  J->second : Src1->getType()->getPointerAddressSpace();
707 
708  auto *C0 = dyn_cast<Constant>(Src0);
709  auto *C1 = dyn_cast<Constant>(Src1);
710 
711  // If one of the inputs is a constant, we may be able to do a constant
712  // addrspacecast of it. Defer inferring the address space until the input
713  // address space is known.
714  if ((C1 && Src0AS == UninitializedAddressSpace) ||
715  (C0 && Src1AS == UninitializedAddressSpace))
716  return None;
717 
718  if (C0 && isSafeToCastConstAddrSpace(C0, Src1AS))
719  NewAS = Src1AS;
720  else if (C1 && isSafeToCastConstAddrSpace(C1, Src0AS))
721  NewAS = Src0AS;
722  else
723  NewAS = joinAddressSpaces(Src0AS, Src1AS);
724  } else {
725  for (Value *PtrOperand : getPointerOperands(V)) {
726  auto I = InferredAddrSpace.find(PtrOperand);
727  unsigned OperandAS = I != InferredAddrSpace.end() ?
728  I->second : PtrOperand->getType()->getPointerAddressSpace();
729 
730  // join(flat, *) = flat. So we can break if NewAS is already flat.
731  NewAS = joinAddressSpaces(NewAS, OperandAS);
732  if (NewAS == FlatAddrSpace)
733  break;
734  }
735  }
736 
737  unsigned OldAS = InferredAddrSpace.lookup(&V);
738  assert(OldAS != FlatAddrSpace);
739  if (OldAS == NewAS)
740  return None;
741  return NewAS;
742 }
743 
744 /// \p returns true if \p U is the pointer operand of a memory instruction with
745 /// a single pointer operand that can have its address space changed by simply
746 /// mutating the use to a new value. If the memory instruction is volatile,
747 /// return true only if the target allows the memory instruction to be volatile
748 /// in the new address space.
750  Use &U, unsigned AddrSpace) {
751  User *Inst = U.getUser();
752  unsigned OpNo = U.getOperandNo();
753  bool VolatileIsAllowed = false;
754  if (auto *I = dyn_cast<Instruction>(Inst))
755  VolatileIsAllowed = TTI.hasVolatileVariant(I, AddrSpace);
756 
757  if (auto *LI = dyn_cast<LoadInst>(Inst))
758  return OpNo == LoadInst::getPointerOperandIndex() &&
759  (VolatileIsAllowed || !LI->isVolatile());
760 
761  if (auto *SI = dyn_cast<StoreInst>(Inst))
762  return OpNo == StoreInst::getPointerOperandIndex() &&
763  (VolatileIsAllowed || !SI->isVolatile());
764 
765  if (auto *RMW = dyn_cast<AtomicRMWInst>(Inst))
766  return OpNo == AtomicRMWInst::getPointerOperandIndex() &&
767  (VolatileIsAllowed || !RMW->isVolatile());
768 
769  if (auto *CmpX = dyn_cast<AtomicCmpXchgInst>(Inst))
771  (VolatileIsAllowed || !CmpX->isVolatile());
772 
773  return false;
774 }
775 
776 /// Update memory intrinsic uses that require more complex processing than
777 /// simple memory instructions. Thse require re-mangling and may have multiple
778 /// pointer operands.
780  Value *NewV) {
781  IRBuilder<> B(MI);
784  MDNode *NoAliasMD = MI->getMetadata(LLVMContext::MD_noalias);
785 
786  if (auto *MSI = dyn_cast<MemSetInst>(MI)) {
787  B.CreateMemSet(NewV, MSI->getValue(),
788  MSI->getLength(), MSI->getDestAlignment(),
789  false, // isVolatile
790  TBAA, ScopeMD, NoAliasMD);
791  } else if (auto *MTI = dyn_cast<MemTransferInst>(MI)) {
792  Value *Src = MTI->getRawSource();
793  Value *Dest = MTI->getRawDest();
794 
795  // Be careful in case this is a self-to-self copy.
796  if (Src == OldV)
797  Src = NewV;
798 
799  if (Dest == OldV)
800  Dest = NewV;
801 
802  if (isa<MemCpyInst>(MTI)) {
803  MDNode *TBAAStruct = MTI->getMetadata(LLVMContext::MD_tbaa_struct);
804  B.CreateMemCpy(Dest, MTI->getDestAlignment(),
805  Src, MTI->getSourceAlignment(),
806  MTI->getLength(),
807  false, // isVolatile
808  TBAA, TBAAStruct, ScopeMD, NoAliasMD);
809  } else {
810  assert(isa<MemMoveInst>(MTI));
811  B.CreateMemMove(Dest, MTI->getDestAlignment(),
812  Src, MTI->getSourceAlignment(),
813  MTI->getLength(),
814  false, // isVolatile
815  TBAA, ScopeMD, NoAliasMD);
816  }
817  } else
818  llvm_unreachable("unhandled MemIntrinsic");
819 
820  MI->eraseFromParent();
821  return true;
822 }
823 
824 // \p returns true if it is OK to change the address space of constant \p C with
825 // a ConstantExpr addrspacecast.
826 bool InferAddressSpaces::isSafeToCastConstAddrSpace(Constant *C, unsigned NewAS) const {
827  assert(NewAS != UninitializedAddressSpace);
828 
829  unsigned SrcAS = C->getType()->getPointerAddressSpace();
830  if (SrcAS == NewAS || isa<UndefValue>(C))
831  return true;
832 
833  // Prevent illegal casts between different non-flat address spaces.
834  if (SrcAS != FlatAddrSpace && NewAS != FlatAddrSpace)
835  return false;
836 
837  if (isa<ConstantPointerNull>(C))
838  return true;
839 
840  if (auto *Op = dyn_cast<Operator>(C)) {
841  // If we already have a constant addrspacecast, it should be safe to cast it
842  // off.
843  if (Op->getOpcode() == Instruction::AddrSpaceCast)
844  return isSafeToCastConstAddrSpace(cast<Constant>(Op->getOperand(0)), NewAS);
845 
846  if (Op->getOpcode() == Instruction::IntToPtr &&
847  Op->getType()->getPointerAddressSpace() == FlatAddrSpace)
848  return true;
849  }
850 
851  return false;
852 }
853 
855  Value::use_iterator End) {
856  User *CurUser = I->getUser();
857  ++I;
858 
859  while (I != End && I->getUser() == CurUser)
860  ++I;
861 
862  return I;
863 }
864 
865 bool InferAddressSpaces::rewriteWithNewAddressSpaces(
866  const TargetTransformInfo &TTI, ArrayRef<WeakTrackingVH> Postorder,
867  const ValueToAddrSpaceMapTy &InferredAddrSpace, Function *F) const {
868  // For each address expression to be modified, creates a clone of it with its
869  // pointer operands converted to the new address space. Since the pointer
870  // operands are converted, the clone is naturally in the new address space by
871  // construction.
872  ValueToValueMapTy ValueWithNewAddrSpace;
873  SmallVector<const Use *, 32> UndefUsesToFix;
874  for (Value* V : Postorder) {
875  unsigned NewAddrSpace = InferredAddrSpace.lookup(V);
876  if (V->getType()->getPointerAddressSpace() != NewAddrSpace) {
877  ValueWithNewAddrSpace[V] = cloneValueWithNewAddressSpace(
878  V, NewAddrSpace, ValueWithNewAddrSpace, &UndefUsesToFix);
879  }
880  }
881 
882  if (ValueWithNewAddrSpace.empty())
883  return false;
884 
885  // Fixes all the undef uses generated by cloneInstructionWithNewAddressSpace.
886  for (const Use *UndefUse : UndefUsesToFix) {
887  User *V = UndefUse->getUser();
888  User *NewV = cast<User>(ValueWithNewAddrSpace.lookup(V));
889  unsigned OperandNo = UndefUse->getOperandNo();
890  assert(isa<UndefValue>(NewV->getOperand(OperandNo)));
891  NewV->setOperand(OperandNo, ValueWithNewAddrSpace.lookup(UndefUse->get()));
892  }
893 
894  SmallVector<Instruction *, 16> DeadInstructions;
895 
896  // Replaces the uses of the old address expressions with the new ones.
897  for (const WeakTrackingVH &WVH : Postorder) {
898  assert(WVH && "value was unexpectedly deleted");
899  Value *V = WVH;
900  Value *NewV = ValueWithNewAddrSpace.lookup(V);
901  if (NewV == nullptr)
902  continue;
903 
904  LLVM_DEBUG(dbgs() << "Replacing the uses of " << *V << "\n with\n "
905  << *NewV << '\n');
906 
907  if (Constant *C = dyn_cast<Constant>(V)) {
908  Constant *Replace = ConstantExpr::getAddrSpaceCast(cast<Constant>(NewV),
909  C->getType());
910  if (C != Replace) {
911  LLVM_DEBUG(dbgs() << "Inserting replacement const cast: " << Replace
912  << ": " << *Replace << '\n');
913  C->replaceAllUsesWith(Replace);
914  V = Replace;
915  }
916  }
917 
918  Value::use_iterator I, E, Next;
919  for (I = V->use_begin(), E = V->use_end(); I != E; ) {
920  Use &U = *I;
921 
922  // Some users may see the same pointer operand in multiple operands. Skip
923  // to the next instruction.
924  I = skipToNextUser(I, E);
925 
927  TTI, U, V->getType()->getPointerAddressSpace())) {
928  // If V is used as the pointer operand of a compatible memory operation,
929  // sets the pointer operand to NewV. This replacement does not change
930  // the element type, so the resultant load/store is still valid.
931  U.set(NewV);
932  continue;
933  }
934 
935  User *CurUser = U.getUser();
936  // Handle more complex cases like intrinsic that need to be remangled.
937  if (auto *MI = dyn_cast<MemIntrinsic>(CurUser)) {
938  if (!MI->isVolatile() && handleMemIntrinsicPtrUse(MI, V, NewV))
939  continue;
940  }
941 
942  if (auto *II = dyn_cast<IntrinsicInst>(CurUser)) {
943  if (rewriteIntrinsicOperands(II, V, NewV))
944  continue;
945  }
946 
947  if (isa<Instruction>(CurUser)) {
948  if (ICmpInst *Cmp = dyn_cast<ICmpInst>(CurUser)) {
949  // If we can infer that both pointers are in the same addrspace,
950  // transform e.g.
951  // %cmp = icmp eq float* %p, %q
952  // into
953  // %cmp = icmp eq float addrspace(3)* %new_p, %new_q
954 
955  unsigned NewAS = NewV->getType()->getPointerAddressSpace();
956  int SrcIdx = U.getOperandNo();
957  int OtherIdx = (SrcIdx == 0) ? 1 : 0;
958  Value *OtherSrc = Cmp->getOperand(OtherIdx);
959 
960  if (Value *OtherNewV = ValueWithNewAddrSpace.lookup(OtherSrc)) {
961  if (OtherNewV->getType()->getPointerAddressSpace() == NewAS) {
962  Cmp->setOperand(OtherIdx, OtherNewV);
963  Cmp->setOperand(SrcIdx, NewV);
964  continue;
965  }
966  }
967 
968  // Even if the type mismatches, we can cast the constant.
969  if (auto *KOtherSrc = dyn_cast<Constant>(OtherSrc)) {
970  if (isSafeToCastConstAddrSpace(KOtherSrc, NewAS)) {
971  Cmp->setOperand(SrcIdx, NewV);
972  Cmp->setOperand(OtherIdx,
973  ConstantExpr::getAddrSpaceCast(KOtherSrc, NewV->getType()));
974  continue;
975  }
976  }
977  }
978 
979  if (AddrSpaceCastInst *ASC = dyn_cast<AddrSpaceCastInst>(CurUser)) {
980  unsigned NewAS = NewV->getType()->getPointerAddressSpace();
981  if (ASC->getDestAddressSpace() == NewAS) {
982  if (ASC->getType()->getPointerElementType() !=
983  NewV->getType()->getPointerElementType()) {
984  NewV = CastInst::Create(Instruction::BitCast, NewV,
985  ASC->getType(), "", ASC);
986  }
987  ASC->replaceAllUsesWith(NewV);
988  DeadInstructions.push_back(ASC);
989  continue;
990  }
991  }
992 
993  // Otherwise, replaces the use with flat(NewV).
994  if (Instruction *I = dyn_cast<Instruction>(V)) {
995  BasicBlock::iterator InsertPos = std::next(I->getIterator());
996  while (isa<PHINode>(InsertPos))
997  ++InsertPos;
998  U.set(new AddrSpaceCastInst(NewV, V->getType(), "", &*InsertPos));
999  } else {
1000  U.set(ConstantExpr::getAddrSpaceCast(cast<Constant>(NewV),
1001  V->getType()));
1002  }
1003  }
1004  }
1005 
1006  if (V->use_empty()) {
1007  if (Instruction *I = dyn_cast<Instruction>(V))
1008  DeadInstructions.push_back(I);
1009  }
1010  }
1011 
1012  for (Instruction *I : DeadInstructions)
1014 
1015  return true;
1016 }
1017 
1019  return new InferAddressSpaces();
1020 }
uint64_t CallInst * C
static bool handleMemIntrinsicPtrUse(MemIntrinsic *MI, Value *OldV, Value *NewV)
Update memory intrinsic uses that require more complex processing than simple memory instructions...
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks &#39;this&#39; from the containing basic block and deletes it.
Definition: Instruction.cpp:68
use_iterator use_end()
Definition: Value.h:346
unsigned getOpcode() const
Return the opcode at the root of this constant expression.
Definition: Constants.h:1199
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
iterator begin() const
Definition: ArrayRef.h:137
constexpr char IsVolatile[]
Key for Kernel::Arg::Metadata::mIsVolatile.
static Constant * getAddrSpaceCast(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1762
static GetElementPtrInst * Create(Type *PointeeType, Value *Ptr, ArrayRef< Value *> IdxList, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Definition: Instructions.h:867
static SelectInst * Create(Value *C, Value *S1, Value *S2, const Twine &NameStr="", Instruction *InsertBefore=nullptr, Instruction *MDFrom=nullptr)
Metadata node.
Definition: Metadata.h:862
F(f)
unsigned getPointerAddressSpace() const
Get the address space of this pointer or pointer vector type.
Definition: DerivedTypes.h:503
CallInst * CreateMemSet(Value *Ptr, Value *Val, uint64_t Size, unsigned Align, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memset to the specified pointer and the specified value.
Definition: IRBuilder.h:404
Hexagon Common GEP
This defines the Use class.
Value * get() const
Definition: Use.h:108
static unsigned getOperandNumForIncomingValue(unsigned i)
AnalysisUsage & addRequired()
This class represents a conversion between pointers from one address space to another.
Type * getPointerElementType() const
Definition: Type.h:376
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
Definition: Type.cpp:639
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:731
CallInst * CreateMemMove(Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign, uint64_t Size, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memmove between the specified pointers.
Definition: IRBuilder.h:494
Type * getSourceElementType() const
Definition: Instructions.h:938
User * getUser() const LLVM_READONLY
Returns the User that contains this Use.
Definition: Use.cpp:41
A constant value that is initialized with an expression using other constant values.
Definition: Constants.h:885
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
Value handle that is nullable, but tries to track the Value.
Definition: ValueHandle.h:182
bool isInBounds() const
Determine whether the GEP has the inbounds flag.
const T & getValue() const LLVM_LVALUE_FUNCTION
Definition: Optional.h:179
static Constant * getSelect(Constant *C, Constant *V1, Constant *V2, Type *OnlyIfReducedTy=nullptr)
Select constant expr.
Definition: Constants.cpp:1925
This class represents a no-op cast from one type to another.
op_iterator idx_begin()
Definition: Instructions.h:966
MDNode * getMetadata(unsigned KindID) const
Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:200
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
unsigned getOpcode() const
Returns a member of one of the enums like Instruction::Add.
Definition: Instruction.h:126
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:439
unsigned getOperandNo() const
Return the operand # of this use in its User.
Definition: Use.cpp:48
bool hasVolatileVariant(Instruction *I, unsigned AddrSpace) const
Return true if the given instruction (assumed to be a memory access instruction) has a volatile varia...
ValueT lookup(const KeyT &Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: ValueMap.h:171
Function * getDeclaration(Module *M, ID id, ArrayRef< Type *> Tys=None)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
Definition: Function.cpp:1007
Value * getOperand(unsigned i) const
Definition: User.h:170
use_iterator_impl< Use > use_iterator
Definition: Value.h:331
static Constant * getBitCast(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1750
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:841
static bool runOnFunction(Function &F, bool PostInlining)
static unsigned getPointerOperandIndex()
Definition: Instructions.h:609
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
Wrapper pass for TargetTransformInfo.
void set(Value *Val)
Definition: Value.h:670
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
static unsigned getPointerOperandIndex()
Definition: Instructions.h:404
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:42
This file contains the declarations for the subclasses of Constant, which represent the different fla...
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:224
std::pair< iterator, bool > insert(const ValueT &V)
Definition: DenseSet.h:187
Represent the analysis usage information of a pass.
void setCalledFunction(Value *Fn)
Set the function called.
This instruction compares its operands according to the predicate given to the constructor.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:285
void setArgOperand(unsigned i, Value *v)
op_range operands()
Definition: User.h:238
void initializeInferAddressSpacesPass(PassRegistry &)
static UndefValue * get(Type *T)
Static factory methods - Return an &#39;undef&#39; object of the specified type.
Definition: Constants.cpp:1392
bool RecursivelyDeleteTriviallyDeadInstructions(Value *V, const TargetLibraryInfo *TLI=nullptr)
If the specified value is a trivially dead instruction, delete it.
Definition: Local.cpp:429
static wasm::ValType getType(const TargetRegisterClass *RC)
Constant * getWithOperands(ArrayRef< Constant *> Ops) const
This returns the current constant expression with the operands replaced with the specified values...
Definition: Constants.h:1219
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:51
static Value * cloneConstantExprWithNewAddressSpace(ConstantExpr *CE, unsigned NewAddrSpace, const ValueToValueMapTy &ValueWithNewAddrSpace)
This is the common base class for memset/memcpy/memmove.
#define DEBUG_TYPE
Iterator for intrusive lists based on ilist_node.
unsigned getNumOperands() const
Definition: User.h:192
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
This pass provides access to the codegen interfaces that are needed for IR-level transformations.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
This is a utility class that provides an abstraction for the common functionality between Instruction...
Definition: Operator.h:31
static Value * cloneInstructionWithNewAddressSpace(Instruction *I, unsigned NewAddrSpace, const ValueToValueMapTy &ValueWithNewAddrSpace, SmallVectorImpl< const Use *> *UndefUsesToFix)
iterator end() const
Definition: ArrayRef.h:138
bool empty() const
Definition: ValueMap.h:146
CallInst * CreateMemCpy(Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign, uint64_t Size, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *TBAAStructTag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memcpy between the specified pointers.
Definition: IRBuilder.h:446
static PHINode * Create(Type *Ty, unsigned NumReservedValues, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Constructors - NumReservedValues is a hint for the number of incoming edges that this phi node will h...
void setPreservesCFG()
This function should be called by the pass, iff they do not:
Definition: Pass.cpp:286
static const unsigned UninitializedAddressSpace
void setOperand(unsigned i, Value *Val)
Definition: User.h:175
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:133
iterator_range< user_iterator > users()
Definition: Value.h:399
INITIALIZE_PASS(InferAddressSpaces, DEBUG_TYPE, "Infer address spaces", false, false) static bool isAddressExpression(const Value &V)
use_iterator use_begin()
Definition: Value.h:338
static CastInst * Create(Instruction::CastOps, Value *S, Type *Ty, const Twine &Name="", Instruction *InsertBefore=nullptr)
Provides a way to construct any of the CastInst subclasses using an opcode instead of the subclass&#39;s ...
bool hasValue() const
Definition: Optional.h:183
FunctionPass * createInferAddressSpacesPass()
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:108
#define I(x, y, z)
Definition: MD5.cpp:58
bool isZero() const
This is just a convenience method to make client code smaller for a common code.
Definition: Constants.h:193
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:323
static unsigned getPointerOperandIndex()
Definition: Instructions.h:785
static unsigned getPointerOperandIndex()
Definition: Instructions.h:276
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Value * getArgOperand(unsigned i) const
getArgOperand/setArgOperand - Return/set the i-th call argument.
aarch64 promote const
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:565
LLVM Value Representation.
Definition: Value.h:73
unsigned getOpcode() const
Return the opcode for this Instruction or ConstantExpr.
Definition: Operator.h:41
static SmallVector< Value *, 2 > getPointerOperands(const Value &V)
static Value::use_iterator skipToNextUser(Value::use_iterator I, Value::use_iterator End)
IRTranslator LLVM IR MI
#define LLVM_FALLTHROUGH
LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
Definition: Compiler.h:238
inst_range instructions(Function *F)
Definition: InstIterator.h:134
PassRegistry - This class manages the registration and intitialization of the pass subsystem as appli...
Definition: PassRegistry.h:39
This pass exposes codegen information to IR-level passes.
#define LLVM_DEBUG(X)
Definition: Debug.h:119
unsigned getFlatAddressSpace() const
Returns the address space ID for a target&#39;s &#39;flat&#39; address space.
static bool isSimplePointerUseValidToReplace(const TargetTransformInfo &TTI, Use &U, unsigned AddrSpace)
returns true if U is the pointer operand of a memory instruction with a single pointer operand that c...
bool use_empty() const
Definition: Value.h:322
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:44
const BasicBlock * getParent() const
Definition: Instruction.h:67
static Value * operandWithNewAddressSpaceOrCreateUndef(const Use &OperandUse, unsigned NewAddrSpace, const ValueToValueMapTy &ValueWithNewAddrSpace, SmallVectorImpl< const Use *> *UndefUsesToFix)