[llvm-commits] [llvm] r115305 - /llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
Eric Christopher
echristo at apple.com
Fri Oct 1 02:02:05 PDT 2010
Author: echristo
Date: Fri Oct 1 04:02:05 2010
New Revision: 115305
URL: http://llvm.org/viewvc/llvm-project?rev=115305&view=rev
Log:
Fix the other half of the alignment changing issue by making sure that the
memcpy alignment is the minimum of the incoming alignments.
Fixes PR 8266.
Modified:
llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=115305&r1=115304&r2=115305&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Fri Oct 1 04:02:05 2010
@@ -697,13 +697,18 @@
M->getParent()->getParent()->getParent(),
M->getIntrinsicID(), ArgTys, 3);
- // Make sure to use the alignment of the source since we're changing the
- // location we're reading from.
+ // Make sure to use the lesser of the alignment of the source and the dest
+ // since we're changing where we're reading from, but don't want to increase
+ // the alignment past what can be read from or written to.
// TODO: Is this worth it if we're creating a less aligned memcpy? For
// example we could be moving from movaps -> movq on x86.
+ unsigned Align = std::min(MDep->getAlignmentCst()->getZExtValue(),
+ M->getAlignmentCst()->getZExtValue());
+ LLVMContext &Context = M->getContext();
+ ConstantInt *AlignCI = ConstantInt::get(Type::getInt32Ty(Context), Align);
Value *Args[5] = {
M->getRawDest(), MDep->getRawSource(), M->getLength(),
- MDep->getAlignmentCst(), M->getVolatileCst()
+ AlignCI, M->getVolatileCst()
};
CallInst *C = CallInst::Create(MemCpyFun, Args, Args+5, "", M);
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