Handle the new !tbaa.struct metadata tags when converting a memcpy into scalar
loads and stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163844 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 1b389b9..486dd13 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -94,6 +94,7 @@
// dest address will be promotable. See if we can find a better type than the
// integer datatype.
Value *StrippedDest = MI->getArgOperand(0)->stripPointerCasts();
+ MDNode *CopyMD = 0;
if (StrippedDest != MI->getArgOperand(0)) {
Type *SrcETy = cast<PointerType>(StrippedDest->getType())
->getElementType();
@@ -105,6 +106,18 @@
if (SrcETy->isSingleValueType()) {
NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp);
NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp);
+
+ // If the memcpy has metadata describing the members, see if we can
+ // get the TBAA tag describing our copy.
+ if (MDNode *M = MI->getMetadata(LLVMContext::MD_tbaa_struct)) {
+ if (M->getNumOperands() == 3 &&
+ isa<ConstantInt>(M->getOperand(0)) &&
+ cast<ConstantInt>(M->getOperand(0))->isNullValue() &&
+ isa<ConstantInt>(M->getOperand(1)) &&
+ cast<ConstantInt>(M->getOperand(1))->getValue() == Size &&
+ isa<MDNode>(M->getOperand(2)))
+ CopyMD = cast<MDNode>(M->getOperand(2));
+ }
}
}
}
@@ -118,8 +131,12 @@
Value *Dest = Builder->CreateBitCast(MI->getArgOperand(0), NewDstPtrTy);
LoadInst *L = Builder->CreateLoad(Src, MI->isVolatile());
L->setAlignment(SrcAlign);
+ if (CopyMD)
+ L->setMetadata(LLVMContext::MD_tbaa, CopyMD);
StoreInst *S = Builder->CreateStore(L, Dest, MI->isVolatile());
S->setAlignment(DstAlign);
+ if (CopyMD)
+ S->setMetadata(LLVMContext::MD_tbaa, CopyMD);
// Set the size of the copy to 0, it will be deleted on the next iteration.
MI->setArgOperand(2, Constant::getNullValue(MemOpLength->getType()));