Define __FINITE_MATH_ONLY__ based on -ffast-math and -ffinite-math-only.

This macro was being unconditionally set to zero, preceded by a FIXME comment.
This fixes <rdar://problem/11845441>.  Patch by Michael Gottesman!

llvm-svn: 160491

2 files changed, 5 insertions, 3 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 016783b1dc5..544c0a270a0 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2100,6 +2100,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.NoInlineDefine = !Opt || Args.hasArg(OPT_fno_inline);
 
   Opts.FastMath = Args.hasArg(OPT_ffast_math);
+  Opts.FiniteMathOnly = Args.hasArg(OPT_ffinite_math_only);
 
   unsigned SSP = Args.getLastArgIntValue(OPT_stack_protector, 0, Diags);
   switch (SSP) {
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 6120d117e3c..3979731ff6f 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -527,9 +527,10 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   if (const char *Prefix = TI.getUserLabelPrefix())
     Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
 
-  // Build configuration options.  FIXME: these should be controlled by
-  // command line options or something.
-  Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
+  if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
+    Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
+  else
+    Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
 
   if (LangOpts.GNUInline)
     Builder.defineMacro("__GNUC_GNU_INLINE__");