From f0a88dbaab5699252c9eb20cac3f23f634e76fa7 Mon Sep 17 00:00:00 2001 From: Matt Arsenault Date: Thu, 23 Feb 2017 03:58:53 +0000 Subject: LoadStoreVectorizer: Split even sized illegal chains properly Implement isLegalToVectorizeLoadChain for AMDGPU to avoid producing private address spaces accesses that will need to be split up later. This was doing the wrong thing in the case where the queried chain was an even number of elements. A possible <4 x i32> store was being split into store <2 x i32> store i32 store i32 rather than store <2 x i32> store <2 x i32> when legal. llvm-svn: 295933 --- llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp') diff --git a/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp b/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp index 20fbcf4533d..4409d7a404f 100644 --- a/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp +++ b/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp @@ -432,9 +432,12 @@ Vectorizer::splitOddVectorElts(ArrayRef Chain, unsigned ElementSizeBytes = ElementSizeBits / 8; unsigned SizeBytes = ElementSizeBytes * Chain.size(); unsigned NumLeft = (SizeBytes - (SizeBytes % 4)) / ElementSizeBytes; - if (NumLeft == Chain.size()) - --NumLeft; - else if (NumLeft == 0) + if (NumLeft == Chain.size()) { + if ((NumLeft & 1) == 0) + NumLeft /= 2; // Split even in half + else + --NumLeft; // Split off last element + } else if (NumLeft == 0) NumLeft = 1; return std::make_pair(Chain.slice(0, NumLeft), Chain.slice(NumLeft)); } -- cgit v1.2.3