From bf56d44cab281a7cec42c6c01caac8e7e7b3ea5c Mon Sep 17 00:00:00 2001 From: Karthik Bhat Date: Fri, 6 Jun 2014 06:20:08 +0000 Subject: Fix PR19657 (scalar loads not combined into vector load) If we have common uses on separate paths in the tree; process the one with greater common depth first. This makes sure that we do not assume we need to extract a load when it is actually going to be part of a vectorized tree. Review: http://reviews.llvm.org/D3800 llvm-svn: 210310 --- llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp') diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp index ce0a009e1cb..d8621670959 100644 --- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -914,8 +914,20 @@ void BoUpSLP::buildTree_rec(ArrayRef VL, unsigned Depth) { if (isa(VL0) && VL0->isCommutative()) { ValueList Left, Right; reorderInputsAccordingToOpcode(VL, Left, Right); - buildTree_rec(Left, Depth + 1); - buildTree_rec(Right, Depth + 1); + BasicBlock *LeftBB = getSameBlock(Left); + BasicBlock *RightBB = getSameBlock(Right); + // If we have common uses on separate paths in the tree make sure we + // process the one with greater common depth first. + // We can use block numbering to determine the subtree traversal as + // earler user has to come in between the common use and the later user. + if (LeftBB && RightBB && LeftBB == RightBB && + getLastIndex(Right) > getLastIndex(Left)) { + buildTree_rec(Right, Depth + 1); + buildTree_rec(Left, Depth + 1); + } else { + buildTree_rec(Left, Depth + 1); + buildTree_rec(Right, Depth + 1); + } return; } -- cgit v1.2.3