MemoryLocation.cpp revision 321369 
1//===- MemoryLocation.cpp - Memory location descriptions -------------------==//
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#include "llvm/Analysis/MemoryLocation.h"
11#include "llvm/Analysis/TargetLibraryInfo.h"
12#include "llvm/IR/BasicBlock.h"
13#include "llvm/IR/DataLayout.h"
14#include "llvm/IR/Instructions.h"
15#include "llvm/IR/IntrinsicInst.h"
16#include "llvm/IR/LLVMContext.h"
17#include "llvm/IR/Module.h"
18#include "llvm/IR/Type.h"
19using namespace llvm;
20
21MemoryLocation MemoryLocation::get(const LoadInst *LI) {
22  AAMDNodes AATags;
23  LI->getAAMetadata(AATags);
24  const auto &DL = LI->getModule()->getDataLayout();
25
26  return MemoryLocation(LI->getPointerOperand(),
27                        DL.getTypeStoreSize(LI->getType()), AATags);
28}
29
30MemoryLocation MemoryLocation::get(const StoreInst *SI) {
31  AAMDNodes AATags;
32  SI->getAAMetadata(AATags);
33  const auto &DL = SI->getModule()->getDataLayout();
34
35  return MemoryLocation(SI->getPointerOperand(),
36                        DL.getTypeStoreSize(SI->getValueOperand()->getType()),
37                        AATags);
38}
39
40MemoryLocation MemoryLocation::get(const VAArgInst *VI) {
41  AAMDNodes AATags;
42  VI->getAAMetadata(AATags);
43
44  return MemoryLocation(VI->getPointerOperand(), UnknownSize, AATags);
45}
46
47MemoryLocation MemoryLocation::get(const AtomicCmpXchgInst *CXI) {
48  AAMDNodes AATags;
49  CXI->getAAMetadata(AATags);
50  const auto &DL = CXI->getModule()->getDataLayout();
51
52  return MemoryLocation(
53      CXI->getPointerOperand(),
54      DL.getTypeStoreSize(CXI->getCompareOperand()->getType()), AATags);
55}
56
57MemoryLocation MemoryLocation::get(const AtomicRMWInst *RMWI) {
58  AAMDNodes AATags;
59  RMWI->getAAMetadata(AATags);
60  const auto &DL = RMWI->getModule()->getDataLayout();
61
62  return MemoryLocation(RMWI->getPointerOperand(),
63                        DL.getTypeStoreSize(RMWI->getValOperand()->getType()),
64                        AATags);
65}
66
67MemoryLocation MemoryLocation::getForSource(const MemTransferInst *MTI) {
68  uint64_t Size = UnknownSize;
69  if (ConstantInt *C = dyn_cast<ConstantInt>(MTI->getLength()))
70    Size = C->getValue().getZExtValue();
71
72  // memcpy/memmove can have AA tags. For memcpy, they apply
73  // to both the source and the destination.
74  AAMDNodes AATags;
75  MTI->getAAMetadata(AATags);
76
77  return MemoryLocation(MTI->getRawSource(), Size, AATags);
78}
79
80MemoryLocation MemoryLocation::getForDest(const MemIntrinsic *MTI) {
81  uint64_t Size = UnknownSize;
82  if (ConstantInt *C = dyn_cast<ConstantInt>(MTI->getLength()))
83    Size = C->getValue().getZExtValue();
84
85  // memcpy/memmove can have AA tags. For memcpy, they apply
86  // to both the source and the destination.
87  AAMDNodes AATags;
88  MTI->getAAMetadata(AATags);
89
90  return MemoryLocation(MTI->getRawDest(), Size, AATags);
91}
92
93MemoryLocation MemoryLocation::getForArgument(ImmutableCallSite CS,
94                                              unsigned ArgIdx,
95                                              const TargetLibraryInfo &TLI) {
96  AAMDNodes AATags;
97  CS->getAAMetadata(AATags);
98  const Value *Arg = CS.getArgument(ArgIdx);
99
100  // We may be able to produce an exact size for known intrinsics.
101  if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
102    const DataLayout &DL = II->getModule()->getDataLayout();
103
104    switch (II->getIntrinsicID()) {
105    default:
106      break;
107    case Intrinsic::memset:
108    case Intrinsic::memcpy:
109    case Intrinsic::memmove:
110      assert((ArgIdx == 0 || ArgIdx == 1) &&
111             "Invalid argument index for memory intrinsic");
112      if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2)))
113        return MemoryLocation(Arg, LenCI->getZExtValue(), AATags);
114      break;
115
116    case Intrinsic::lifetime_start:
117    case Intrinsic::lifetime_end:
118    case Intrinsic::invariant_start:
119      assert(ArgIdx == 1 && "Invalid argument index");
120      return MemoryLocation(
121          Arg, cast<ConstantInt>(II->getArgOperand(0))->getZExtValue(), AATags);
122
123    case Intrinsic::invariant_end:
124      assert(ArgIdx == 2 && "Invalid argument index");
125      return MemoryLocation(
126          Arg, cast<ConstantInt>(II->getArgOperand(1))->getZExtValue(), AATags);
127
128    case Intrinsic::arm_neon_vld1:
129      assert(ArgIdx == 0 && "Invalid argument index");
130      // LLVM's vld1 and vst1 intrinsics currently only support a single
131      // vector register.
132      return MemoryLocation(Arg, DL.getTypeStoreSize(II->getType()), AATags);
133
134    case Intrinsic::arm_neon_vst1:
135      assert(ArgIdx == 0 && "Invalid argument index");
136      return MemoryLocation(
137          Arg, DL.getTypeStoreSize(II->getArgOperand(1)->getType()), AATags);
138    }
139  }
140
141  // We can bound the aliasing properties of memset_pattern16 just as we can
142  // for memcpy/memset.  This is particularly important because the
143  // LoopIdiomRecognizer likes to turn loops into calls to memset_pattern16
144  // whenever possible.
145  LibFunc F;
146  if (CS.getCalledFunction() && TLI.getLibFunc(*CS.getCalledFunction(), F) &&
147      F == LibFunc_memset_pattern16 && TLI.has(F)) {
148    assert((ArgIdx == 0 || ArgIdx == 1) &&
149           "Invalid argument index for memset_pattern16");
150    if (ArgIdx == 1)
151      return MemoryLocation(Arg, 16, AATags);
152    if (const ConstantInt *LenCI = dyn_cast<ConstantInt>(CS.getArgument(2)))
153      return MemoryLocation(Arg, LenCI->getZExtValue(), AATags);
154  }
155  // FIXME: Handle memset_pattern4 and memset_pattern8 also.
156
157  return MemoryLocation(CS.getArgument(ArgIdx), UnknownSize, AATags);
158}
159