lib/Analysis/MemoryLocation.cpp

   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"
  19 using namespace llvm;
  20
  21 MemoryLocation 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
  30 MemoryLocation 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
  40 MemoryLocation MemoryLocation::get(const VAArgInst *VI) {
  41   AAMDNodes AATags;
  42   VI->getAAMetadata(AATags);
  43
  44   return MemoryLocation(VI->getPointerOperand(), UnknownSize, AATags);
  45 }
  46
  47 MemoryLocation 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
  57 MemoryLocation 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
  67 MemoryLocation 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
  80 MemoryLocation 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
  93 MemoryLocation 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 }