From c6b8e20a5c59d8635ecf7141e700dafae782602e Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Tue, 18 Nov 2014 22:06:45 +0000 Subject: InstCombine: Fix another infinite loop caused by visitFPTrunc We would attempt to replace an frem's operand with the same operand. This would cause InstCombine to think real work was done, causing InstCombine to enter an infinite loop. This fixes the second part of PR21576. llvm-svn: 222265 --- llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp') diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index a0570f7ebd4..aba77bb4462 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1269,13 +1269,12 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) { // type of OpI doesn't enter into things at all. We simply evaluate // in whichever source type is larger, then convert to the // destination type. - Value *NewLHS = LHSOrig, *NewRHS = RHSOrig; if (LHSWidth < SrcWidth) - NewLHS = Builder->CreateFPExt(NewLHS, RHSOrig->getType()); + LHSOrig = Builder->CreateFPExt(LHSOrig, RHSOrig->getType()); else if (RHSWidth <= SrcWidth) - NewRHS = Builder->CreateFPExt(NewRHS, LHSOrig->getType()); - if (NewLHS != LHSOrig || NewRHS != RHSOrig) { - Value *ExactResult = Builder->CreateFRem(NewLHS, NewRHS); + RHSOrig = Builder->CreateFPExt(RHSOrig, LHSOrig->getType()); + if (LHSOrig != OpI->getOperand(0) || RHSOrig != OpI->getOperand(1)) { + Value *ExactResult = Builder->CreateFRem(LHSOrig, RHSOrig); if (Instruction *RI = dyn_cast(ExactResult)) RI->copyFastMathFlags(OpI); return CastInst::CreateFPCast(ExactResult, CI.getType()); -- cgit v1.2.3