From 7e8cebf22d170769b0bf0c2a69309faa0e36ac4c Mon Sep 17 00:00:00 2001 From: Arnold Schwaighofer Date: Tue, 29 Oct 2013 01:33:53 +0000 Subject: ARM cost model: Account for zero cost scalar SROA instructions By vectorizing a series of srl, or, ... instructions we have obfuscated the intention so much that the backend does not know how to fold this code away. radar://15336950 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193573 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Vectorize/SLPVectorizer.cpp | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) (limited to 'lib/Transforms') diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp index 012521ad01..2797a21421 100644 --- a/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -1013,9 +1013,24 @@ int BoUpSLP::getEntryCost(TreeEntry *E) { TTI->getCmpSelInstrCost(Opcode, ScalarTy, Builder.getInt1Ty()); VecCost = TTI->getCmpSelInstrCost(Opcode, VecTy, MaskTy); } else { - ScalarCost = VecTy->getNumElements() * - TTI->getArithmeticInstrCost(Opcode, ScalarTy); - VecCost = TTI->getArithmeticInstrCost(Opcode, VecTy); + // Certain instructions can be cheaper to vectorize if they have a + // constant second vector operand. + TargetTransformInfo::OperandValueKind Op1VK = + TargetTransformInfo::OK_AnyValue; + TargetTransformInfo::OperandValueKind Op2VK = + TargetTransformInfo::OK_UniformConstantValue; + + // Check whether all second operands are constant. + for (unsigned i = 0; i < VL.size(); ++i) + if (!isa(cast(VL[i])->getOperand(1))) { + Op2VK = TargetTransformInfo::OK_AnyValue; + break; + } + + ScalarCost = + VecTy->getNumElements() * + TTI->getArithmeticInstrCost(Opcode, ScalarTy, Op1VK, Op2VK); + VecCost = TTI->getArithmeticInstrCost(Opcode, VecTy, Op1VK, Op2VK); } return VecCost - ScalarCost; } -- cgit v1.2.3