From 838d13e7ee6168ec31822b8278949cfe6266ac1e Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Mon, 10 Apr 2017 07:00:10 +0000 Subject: [InstCombine] Make sure we preserve fast math flags when folding fp instructions into phi nodes Summary: I noticed in the select folding code that we copied fast math flags, but did not do the same for the similar handling in phi nodes. This patch fixes that to do the same thing as select Reviewers: spatel, davide, majnemer, hfinkel Reviewed By: davide Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D31690 llvm-svn: 299838 --- llvm/lib/Transforms/InstCombine/InstructionCombining.cpp | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Transforms/InstCombine/InstructionCombining.cpp') diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index bc168dd5776..398b49748ec 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -937,11 +937,15 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { Constant *C = cast(I.getOperand(1)); for (unsigned i = 0; i != NumPHIValues; ++i) { Value *InV = nullptr; - if (Constant *InC = dyn_cast(PN->getIncomingValue(i))) + if (Constant *InC = dyn_cast(PN->getIncomingValue(i))) { InV = ConstantExpr::get(I.getOpcode(), InC, C); - else + } else { InV = Builder->CreateBinOp(cast(I).getOpcode(), PN->getIncomingValue(i), C, "phitmp"); + auto *FPInst = dyn_cast(InV); + if (FPInst && isa(FPInst)) + FPInst->copyFastMathFlags(&I); + } NewPN->addIncoming(InV, PN->getIncomingBlock(i)); } } else { -- cgit v1.2.3