[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304806 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/IR/IRBuilder.cpp b/lib/IR/IRBuilder.cpp
index 261757aef55..81b02946e1d 100644
--- a/lib/IR/IRBuilder.cpp
+++ b/lib/IR/IRBuilder.cpp
@@ -134,6 +134,38 @@ CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align,
   return CI;  
 }
 
+CallInst *IRBuilderBase::CreateElementAtomicMemCpy(
+    Value *Dst, Value *Src, Value *NumElements, uint32_t ElementSize,
+    MDNode *TBAATag, MDNode *TBAAStructTag, MDNode *ScopeTag,
+    MDNode *NoAliasTag) {
+  Dst = getCastedInt8PtrValue(Dst);
+  Src = getCastedInt8PtrValue(Src);
+
+  Value *Ops[] = {Dst, Src, NumElements, getInt32(ElementSize)};
+  Type *Tys[] = {Dst->getType(), Src->getType()};
+  Module *M = BB->getParent()->getParent();
+  Value *TheFn =
+      Intrinsic::getDeclaration(M, Intrinsic::memcpy_element_atomic, Tys);
+
+  CallInst *CI = createCallHelper(TheFn, Ops, this);
+
+  // Set the TBAA info if present.
+  if (TBAATag)
+    CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
+
+  // Set the TBAA Struct info if present.
+  if (TBAAStructTag)
+    CI->setMetadata(LLVMContext::MD_tbaa_struct, TBAAStructTag);
+
+  if (ScopeTag)
+    CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
+
+  if (NoAliasTag)
+    CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
+
+  return CI;
+}
+
 CallInst *IRBuilderBase::
 CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align,
               bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag,