Fix how cc1 command line options are mapped into FP options.

Canonicalize on storing FP options in LangOptions instead of
redundantly in CodeGenOptions.  Incorporate -ffast-math directly
into the values of those LangOptions rather than considering it
separately when building FPOptions.  Build IR attributes from
those options rather than a mix of sources.

We should really simplify the driver/cc1 interaction here and have
the driver pass down options that cc1 directly honors.  That can
happen in a follow-up, though.

Patch by Michele Scandale!
https://reviews.llvm.org/D80315

1 files changed, 13 insertions, 20 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index a348103..d6622a4 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -71,26 +71,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
   if (!suppressNewContext)
     CGM.getCXXABI().getMangleContext().startNewFunction();
 
-  llvm::FastMathFlags FMF;
-  if (CGM.getLangOpts().FastMath)
-    FMF.setFast();
-  if (CGM.getLangOpts().FiniteMathOnly) {
-    FMF.setNoNaNs();
-    FMF.setNoInfs();
-  }
-  if (CGM.getCodeGenOpts().NoNaNsFPMath) {
-    FMF.setNoNaNs();
-  }
-  if (CGM.getCodeGenOpts().NoSignedZeros) {
-    FMF.setNoSignedZeros();
-  }
-  if (CGM.getCodeGenOpts().ReciprocalMath) {
-    FMF.setAllowReciprocal();
-  }
-  if (CGM.getCodeGenOpts().Reassociate) {
-    FMF.setAllowReassoc();
-  }
-  Builder.setFastMathFlags(FMF);
+  SetFastMathFlags(FPOptions(CGM.getLangOpts()));
   SetFPModel();
 }
 
@@ -139,6 +120,18 @@ void CodeGenFunction::SetFPModel() {
                              RM != llvm::RoundingMode::NearestTiesToEven);
 }
 
+void CodeGenFunction::SetFastMathFlags(FPOptions FPFeatures) {
+  llvm::FastMathFlags FMF;
+  FMF.setAllowReassoc(FPFeatures.allowAssociativeMath());
+  FMF.setNoNaNs(FPFeatures.noHonorNaNs());
+  FMF.setNoInfs(FPFeatures.noHonorInfs());
+  FMF.setNoSignedZeros(FPFeatures.noSignedZeros());
+  FMF.setAllowReciprocal(FPFeatures.allowReciprocalMath());
+  FMF.setApproxFunc(FPFeatures.allowApproximateFunctions());
+  FMF.setAllowContract(FPFeatures.allowFPContractAcrossStatement());
+  Builder.setFastMathFlags(FMF);
+}
+
 LValue CodeGenFunction::MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T) {
   LValueBaseInfo BaseInfo;
   TBAAAccessInfo TBAAInfo;