From ce3623782657d77cefbd03ab0d545a0805e9c5e9 Mon Sep 17 00:00:00 2001 From: Arnold Schwaighofer Date: Fri, 28 Mar 2014 17:21:32 +0000 Subject: SLPVectorizer: Take credit for free extractelement instructions Extract element instructions that will be removed when vectorzing lower the cost. Patch by Arch D. Robison! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205020 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Vectorize/SLPVectorizer.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'lib/Transforms') diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp index 6d1c2c0ffe..d2d4db33f6 100644 --- a/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -1015,8 +1015,17 @@ int BoUpSLP::getEntryCost(TreeEntry *E) { return 0; } case Instruction::ExtractElement: { - if (CanReuseExtract(VL)) - return 0; + if (CanReuseExtract(VL)) { + int DeadCost = 0; + for (unsigned i = 0, e = VL.size(); i < e; ++i) { + ExtractElementInst *E = cast(VL[i]); + if (E->hasOneUse()) + // Take credit for instruction that will become dead. + DeadCost += + TTI->getVectorInstrCost(Instruction::ExtractElement, VecTy, i); + } + return -DeadCost; + } return getGatherCost(VecTy); } case Instruction::ZExt: -- cgit v1.2.3