Add -ffp-contract = { fast | on | off } command line option support.
This flag sets the 'fp-contract' mode, which controls the formation of fused
floating point operations. Available modes are:
- Fast: Form fused operations anywhere.
- On: Form fused operations where allowed by FP_CONTRACT. This is the default
mode.
- Off: Don't form fused operations (in future this may be relaxed to forming
fused operations where it can be proved that the result won't be
affected).
Currently clang doesn't support the FP_CONTRACT pragma, so the 'On' and 'Off'
modes are equivalent.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159794 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index 5a97875..0a1915b 100644
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -351,6 +351,19 @@
Options.FloatABIType = llvm::FloatABI::Default;
}
+ // Set FP fusion mode.
+ switch (LangOpts.getFPContractMode()) {
+ case LangOptions::FPC_Off:
+ Options.AllowFPOpFusion = llvm::FPOpFusion::Strict;
+ break;
+ case LangOptions::FPC_On:
+ Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
+ break;
+ case LangOptions::FPC_Fast:
+ Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
+ break;
+ }
+
Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;