From 5a4f7cf2ff3fc15d82ca062ee64dd8bd01a68883 Mon Sep 17 00:00:00 2001 From: Sanjay Patel Date: Wed, 22 May 2019 15:50:46 +0000 Subject: [IR] allow fast-math-flags on select of FP values This is a minimal start to correcting a problem most directly discussed in PR38086: https://bugs.llvm.org/show_bug.cgi?id=38086 We have been hacking around a limitation for FP select patterns by using the fast-math-flags on the condition of the select rather than the select itself. This patch just allows FMF to appear with the 'select' opcode. No changes are needed to "FPMathOperator" because it already includes select-of-FP because that definition is based on the (return) value type. Once we have this ability, we can start correcting and adding IR transforms to use the FMF on a 'select' instruction. The instcombine and vectorizer test diffs only show that the IRBuilder change is behaving as expected by applying an FMF guard value to 'select'. For reference: rL241901 - allowed FMF with fcmp rL255555 - allowed FMF with FP calls Differential Revision: https://reviews.llvm.org/D61917 llvm-svn: 361401 --- llvm/lib/AsmParser/LLParser.cpp | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'llvm/lib/AsmParser/LLParser.cpp') diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp index 56012490c45..f16f6a2af49 100644 --- a/llvm/lib/AsmParser/LLParser.cpp +++ b/llvm/lib/AsmParser/LLParser.cpp @@ -5701,7 +5701,19 @@ int LLParser::ParseInstruction(Instruction *&Inst, BasicBlock *BB, case lltok::kw_inttoptr: case lltok::kw_ptrtoint: return ParseCast(Inst, PFS, KeywordVal); // Other. - case lltok::kw_select: return ParseSelect(Inst, PFS); + case lltok::kw_select: { + FastMathFlags FMF = EatFastMathFlagsIfPresent(); + int Res = ParseSelect(Inst, PFS); + if (Res != 0) + return Res; + if (FMF.any()) { + if (!Inst->getType()->isFPOrFPVectorTy()) + return Error(Loc, "fast-math-flags specified for select without " + "floating-point scalar or vector return type"); + Inst->setFastMathFlags(FMF); + } + return 0; + } case lltok::kw_va_arg: return ParseVA_Arg(Inst, PFS); case lltok::kw_extractelement: return ParseExtractElement(Inst, PFS); case lltok::kw_insertelement: return ParseInsertElement(Inst, PFS); -- cgit v1.2.3