Fix PR11685 by implementing -ffast-math and its various friends in the
Clang driver. This involves a bunch of silly option parsing code to try
to carefully emulate GCC's options. Currently, this takes a conservative
approach, and unless all of the unsafe optimizations are enabled, none
of them are. The fine grained control doesn't seem particularly useful.
If it ever becomes useful, we can add that to LLVM first, and then
expose it here.
This also fixes a few tiny bugs in the flag management around
-fhonor-infinities and -fhonor-nans; the flags now form proper sets both
for enabling and disabling, with the last flag winning.
I've also implemented a moderately terrifying GCC feature where
a language change is also provided by the '-ffast-math' flag by defining
the __FAST_MATH__ preprocessor macro. This feature is tracked and
serialized in the frontend but it isn't used yet. A subsequent patch
will add the preprocessor macro and tests for it.
I've manually tested that codegen appears to respect this, but I've not
dug in enough to see if there is an easy way to test codegen options w/o
relying on the particulars of LLVM's optimizations.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147434 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Driver/ArgList.h b/include/clang/Driver/ArgList.h
index 04faf64..f969804 100644
--- a/include/clang/Driver/ArgList.h
+++ b/include/clang/Driver/ArgList.h
@@ -185,6 +185,8 @@
Arg *getLastArg(OptSpecifier Id0, OptSpecifier Id1, OptSpecifier Id2) const;
Arg *getLastArg(OptSpecifier Id0, OptSpecifier Id1, OptSpecifier Id2,
OptSpecifier Id3) const;
+ Arg *getLastArg(OptSpecifier Id0, OptSpecifier Id1, OptSpecifier Id2,
+ OptSpecifier Id3, OptSpecifier Id4) const;
/// getArgString - Return the input argument string at \arg Index.
virtual const char *getArgString(unsigned Index) const = 0;
diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index d275af2..ec6e03b 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -170,6 +170,9 @@
HelpText<"Allow optimization to assume there are no infinities.">;
def menable_no_nans : Flag<"-menable-no-nans">,
HelpText<"Allow optimization to assume there are no NaNs.">;
+def menable_unsafe_fp_math : Flag<"-menable-unsafe-fp-math">,
+ HelpText<"Allow unsafe floating-point math optimizations which may decrease "
+ "precision">;
def mfloat_abi : Separate<"-mfloat-abi">,
HelpText<"The float ABI to use">;
def mno_global_merge : Flag<"-mno-global-merge">,
@@ -482,6 +485,10 @@
HelpText<"Enable C++ exceptions">;
def fsjlj_exceptions : Flag<"-fsjlj-exceptions">,
HelpText<"Use SjLj style exceptions">;
+def ffast_math : Flag<"-ffast-math">,
+ HelpText<"Enable the *frontend*'s 'fast-math' mode. This has no effect on "
+ "optimizations, but provides a preprocessor macro __FAST_MATH__ the "
+ "same as GCC's -ffast-math flag.">;
def ffreestanding : Flag<"-ffreestanding">,
HelpText<"Assert that the compilation takes place in a freestanding environment">;
def fgnu_runtime : Flag<"-fgnu-runtime">,
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 892a972..08b3f03 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -319,8 +319,23 @@
def fexceptions : Flag<"-fexceptions">, Group<f_Group>;
def fextdirs_EQ : Joined<"-fextdirs=">, Group<f_Group>;
def fhosted : Flag<"-fhosted">, Group<f_Group>;
-def ffast_math : Flag<"-ffast-math">, Group<clang_ignored_f_Group>;
+def ffast_math : Flag<"-ffast-math">, Group<f_Group>;
+def fmath_errno : Flag<"-fmath-errno">, Group<f_Group>;
+def fno_math_errno : Flag<"-fno-math-errno">, Group<f_Group>;
+def fsignaling_math : Flag<"-fsignaling-math">, Group<f_Group>;
+def fno_signaling_math : Flag<"-fno-signaling-math">, Group<f_Group>;
+def funsafe_math_optimizations : Flag<"-funsafe-math-optimizations">,
+ Group<f_Group>;
+def fno_unsafe_math_optimizations : Flag<"-fno-unsafe-math-optimizations">,
+ Group<f_Group>;
+def fassociative_math : Flag<"-fassociative-math">, Group<f_Group>;
+def fno_associative_math : Flag<"-fno-associative-math">, Group<f_Group>;
+def freciprocal_math : Flag<"-freciprocal-math">, Group<f_Group>;
+def fno_reciprocal_math : Flag<"-fno-reciprocal-math">, Group<f_Group>;
def ffinite_math_only : Flag<"-ffinite-math-only">, Group<f_Group>;
+def fno_finite_math_only : Flag<"-fno-finite-math-only">, Group<f_Group>;
+def fsigned_zeros : Flag<"-fsigned-zeros">, Group<f_Group>;
+def fno_signed_zeros : Flag<"-fno-signed-zeros">, Group<f_Group>;
def fhonor_nans : Flag<"-fhonor-nans">, Group<f_Group>;
def fno_honor_nans : Flag<"-fno-honor-nans">, Group<f_Group>;
def fhonor_infinities : Flag<"-fhonor-infinities">, Group<f_Group>;
@@ -330,6 +345,8 @@
Alias<fhonor_infinities>;
def fno_honor_infinites : Flag<"-fno-honor-infinites">, Group<f_Group>,
Alias<fno_honor_infinities>;
+def ftrapping_math : Flag<"-ftrapping-math">, Group<f_Group>;
+def fno_trapping_math : Flag<"-fno-trapping-math">, Group<f_Group>;
def ffor_scope : Flag<"-ffor-scope">, Group<f_Group>;
def fno_for_scope : Flag<"-fno-for-scope">, Group<f_Group>;
@@ -355,7 +372,6 @@
def fno_lto : Flag<"-fno-lto">, Group<f_Group>;
def fmacro_backtrace_limit_EQ : Joined<"-fmacro-backtrace-limit=">,
Group<f_Group>;
-def fmath_errno : Flag<"-fmath-errno">, Group<f_Group>;
def fmerge_all_constants : Flag<"-fmerge-all-constants">, Group<f_Group>;
def fmessage_length_EQ : Joined<"-fmessage-length=">, Group<f_Group>;
def fms_extensions : Flag<"-fms-extensions">, Group<f_Group>;
@@ -394,7 +410,6 @@
def fno_elide_constructors : Flag<"-fno-elide-constructors">, Group<f_Group>;
def fno_eliminate_unused_debug_symbols : Flag<"-fno-eliminate-unused-debug-symbols">, Group<f_Group>;
def fno_exceptions : Flag<"-fno-exceptions">, Group<f_Group>;
-def fno_finite_math_only : Flag<"-fno-finite-math-only">, Group<clang_ignored_f_Group>;
def fno_gnu_keywords : Flag<"-fno-gnu-keywords">, Group<f_Group>;
def fno_inline_functions : Flag<"-fno-inline-functions">, Group<clang_ignored_f_Group>;
def fno_inline : Flag<"-fno-inline">, Group<clang_ignored_f_Group>;
@@ -402,7 +417,6 @@
def fno_lax_vector_conversions : Flag<"-fno-lax-vector-conversions">, Group<f_Group>;
def fno_limit_debug_info : Flag<"-fno-limit-debug-info">, Group<f_Group>,
HelpText<"Do not limit debug information produced to reduce size of debug binary">;
-def fno_math_errno : Flag<"-fno-math-errno">, Group<f_Group>;
def fno_merge_all_constants : Flag<"-fno-merge-all-constants">, Group<f_Group>;
def fno_ms_extensions : Flag<"-fno-ms-extensions">, Group<f_Group>;
def fno_ms_compatibility : Flag<"-fno-ms-compatibility">, Group<f_Group>;