- // Finally, handle specific knowledge of intrinsics.
- const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction());
- if (II != 0)
- switch (II->getIntrinsicID()) {
- default: break;
- case Intrinsic::memcpy:
- case Intrinsic::memmove: {
- uint64_t Len = UnknownSize;
- if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2)))
- Len = LenCI->getZExtValue();
- Value *Dest = II->getArgOperand(0);
- Value *Src = II->getArgOperand(1);
- // If it can't overlap the source dest, then it doesn't modref the loc.
- if (isNoAlias(Location(Dest, Len), Loc)) {
- if (isNoAlias(Location(Src, Len), Loc))
- return NoModRef;
- // If it can't overlap the dest, then worst case it reads the loc.
- Min = Ref;
- } else if (isNoAlias(Location(Src, Len), Loc)) {
- // If it can't overlap the source, then worst case it mutates the loc.
- Min = Mod;
- }
- break;
- }
- case Intrinsic::memset:
- // Since memset is 'accesses arguments' only, the AliasAnalysis base class
- // will handle it for the variable length case.
- if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2))) {
- uint64_t Len = LenCI->getZExtValue();
- Value *Dest = II->getArgOperand(0);
- if (isNoAlias(Location(Dest, Len), Loc))
- return NoModRef;
- }
- // We know that memset doesn't load anything.
- Min = Mod;
- break;
- case Intrinsic::atomic_cmp_swap:
- case Intrinsic::atomic_swap:
- case Intrinsic::atomic_load_add:
- case Intrinsic::atomic_load_sub:
- case Intrinsic::atomic_load_and:
- case Intrinsic::atomic_load_nand:
- case Intrinsic::atomic_load_or:
- case Intrinsic::atomic_load_xor:
- case Intrinsic::atomic_load_max:
- case Intrinsic::atomic_load_min:
- case Intrinsic::atomic_load_umax:
- case Intrinsic::atomic_load_umin:
- if (TD) {
- Value *Op1 = II->getArgOperand(0);
- uint64_t Op1Size = TD->getTypeStoreSize(Op1->getType());
- MDNode *Tag = II->getMetadata(LLVMContext::MD_tbaa);
- if (isNoAlias(Location(Op1, Op1Size, Tag), Loc))
- return NoModRef;
- }
- break;
- case Intrinsic::lifetime_start:
- case Intrinsic::lifetime_end:
- case Intrinsic::invariant_start: {
- uint64_t PtrSize =
- cast<ConstantInt>(II->getArgOperand(0))->getZExtValue();
- if (isNoAlias(Location(II->getArgOperand(1),
- PtrSize,
- II->getMetadata(LLVMContext::MD_tbaa)),
- Loc))
- return NoModRef;
- break;
- }
- case Intrinsic::invariant_end: {
- uint64_t PtrSize =
- cast<ConstantInt>(II->getArgOperand(1))->getZExtValue();
- if (isNoAlias(Location(II->getArgOperand(2),
- PtrSize,
- II->getMetadata(LLVMContext::MD_tbaa)),
- Loc))
- return NoModRef;
- break;
- }
- case Intrinsic::arm_neon_vld1: {
- // LLVM's vld1 and vst1 intrinsics currently only support a single
- // vector register.
- uint64_t Size =
- TD ? TD->getTypeStoreSize(II->getType()) : UnknownSize;
- if (isNoAlias(Location(II->getArgOperand(0), Size,
- II->getMetadata(LLVMContext::MD_tbaa)),
- Loc))
- return NoModRef;
- break;
- }
- case Intrinsic::arm_neon_vst1: {
- uint64_t Size =
- TD ? TD->getTypeStoreSize(II->getArgOperand(1)->getType()) : UnknownSize;
- if (isNoAlias(Location(II->getArgOperand(0), Size,
- II->getMetadata(LLVMContext::MD_tbaa)),
- Loc))
- return NoModRef;
- break;
- }
- }