[Atomics][LoopIdiom] Recognize unordered atomic memcpy

Summary:
Expanding the loop idiom test for memcpy to also recognize
unordered atomic memcpy. The only difference for recognizing
an unordered atomic memcpy and instead of a normal memcpy is
that the loads and/or stores involved are unordered atomic operations.

Background:  http://lists.llvm.org/pipermail/llvm-dev/2017-May/112779.html

Patch by Daniel Neilson!

Reviewers: reames, anna, skatkov

Reviewed By: reames, anna

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D33243

llvm-svn: 304806

2 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index fe94079fd86..1d58cccc308 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -1383,6 +1383,8 @@ int X86TTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy,
   return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I);
 }
 
+unsigned X86TTIImpl::getAtomicMemIntrinsicMaxElementSize() const { return 16; }
+
 int X86TTIImpl::getIntrinsicInstrCost(Intrinsic::ID IID, Type *RetTy,
                                       ArrayRef<Type *> Tys, FastMathFlags FMF,
                                       unsigned ScalarizationCostPassed) {
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.h b/llvm/lib/Target/X86/X86TargetTransformInfo.h
index 9bef9e80c39..b907b7556a1 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.h
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.h
@@ -76,6 +76,8 @@ public:
   int getAddressComputationCost(Type *PtrTy, ScalarEvolution *SE,
                                 const SCEV *Ptr);
 
+  unsigned getAtomicMemIntrinsicMaxElementSize() const;
+
   int getIntrinsicInstrCost(Intrinsic::ID IID, Type *RetTy,
                             ArrayRef<Type *> Tys, FastMathFlags FMF,
                             unsigned ScalarizationCostPassed = UINT_MAX);