Driver: Link crtfastmath.o if it's available and -ffast-math is specified.
crtfastmath.o contains routines to set the floating point flags to a faster,
unsafe mode. Linking it in speeds up code dealing with denormals significantly
(PR14024).
For now this is only enabled on linux where I can test it and crtfastmath.o is
widely available. We may want to provide a similar file with compiler-rt
eventually and/or enable it on other platforms too.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Driver/ToolChain.h b/include/clang/Driver/ToolChain.h
index 3295e72..d694e0f 100644
--- a/include/clang/Driver/ToolChain.h
+++ b/include/clang/Driver/ToolChain.h
@@ -252,6 +252,13 @@
/// for kernel extensions (Darwin-specific).
virtual void AddCCKextLibArgs(const ArgList &Args,
ArgStringList &CmdArgs) const;
+
+ /// AddFastMathRuntimeIfAvailable - If a runtime library exists that sets
+ /// global flags for unsafe floating point math, add it and return true.
+ ///
+ /// This checks for presence of the -ffast-math or -funsafe-math flags.
+ virtual bool AddFastMathRuntimeIfAvailable(const ArgList &Args,
+ ArgStringList &CmdArgs) const;
};
} // end namespace driver