From a3f4bb33fd235a170d41a6d12db060192e02f451 Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Wed, 2 Oct 2019 12:32:52 +0000 Subject: [PATCH] [InstCombine] Simplify fma multiplication to nan for undef or nan operands. In similar fashion to D67721, we can simplify FMA multiplications if any of the operands is NaN or undef. In instcombine, we will simplify the FMA to an fadd with a NaN operand, which in turn gets folded to NaN. Note that this just changes SimplifyFMAFMul, so we still not catch the case where only the Add part of the FMA is Nan/Undef. Reviewers: cameron.mcinally, mcberg2017, spatel, arsenm Reviewed By: cameron.mcinally Differential Revision: https://reviews.llvm.org/D68265 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373459 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index ca00adff773..cb898772170 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -4592,6 +4592,9 @@ static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF, static Value *SimplifyFMAFMul(Value *Op0, Value *Op1, FastMathFlags FMF, const SimplifyQuery &Q, unsigned MaxRecurse) { + if (Constant *C = simplifyFPOp({Op0, Op1})) + return C; + // fmul X, 1.0 ==> X if (match(Op1, m_FPOne())) return Op0; @@ -4626,9 +4629,6 @@ static Value *SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *C = foldOrCommuteConstant(Instruction::FMul, Op0, Op1, Q)) return C; - if (Constant *C = simplifyFPOp({Op0, Op1})) - return C; - // Now apply simplifications that do not require rounding. return SimplifyFMAFMul(Op0, Op1, FMF, Q, MaxRecurse); } -- 2.50.1