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author | Joseph Myers <joseph@codesourcery.com> | 2014-11-12 13:33:45 +0000 |
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committer | Joseph Myers <jsm28@gcc.gnu.org> | 2014-11-12 13:33:45 +0000 |
commit | 2079956a87de079b4a04ac938141e437e60bbff8 (patch) | |
tree | d88a9be0aeb520b5e2b97631474f3e34c980ada8 /gcc/cppbuiltin.c | |
parent | b9700367fa3ab754909f3b2930b432c34a74a691 (diff) | |
download | gcc-2079956a87de079b4a04ac938141e437e60bbff8.zip gcc-2079956a87de079b4a04ac938141e437e60bbff8.tar.gz gcc-2079956a87de079b4a04ac938141e437e60bbff8.tar.bz2 |
Predefine __NO_MATH_ERRNO__ for -fno-math-errno.
This patch adds a predefined macro __NO_MATH_ERRNO__ for when
-fno-math-errno is passed or implied. This allows math.h to provide a
more accurate definition of the C99 math_errhandling macro that takes
this option into account, and allows for choice of libm functions to
be optimized at compile time based on this option.
(There may be a case for such interfaces for -fno-rounding-math
(default) and -fno-trapping-math as well, but as C99 standard pragmas
would allow those to vary on a per-block basis, predefined macros
would be problematic as the interface; you can't select a
-fno-trapping-math or -fno-rounding-math version of a function in a
standard header if a conforming program could then use "#pragma STDC
FENV_ACCESS ON" to require a -ftrapping-math -frounding-math version
in a particular block. So built-in functions might be a better way of
providing access to information about those options.)
Bootstrapped with no regressions on x86_64-unknown-linux-gnu. OK to
commit?
* cppbuiltin.c (define_builtin_macros_for_compilation_flags):
Define __NO_MATH_ERRNO__ if -fno-math-errno.
* doc/cpp.texi (__NO_MATH_ERRNO__): Document predefined macro.
c-family:
* c-cppbuiltin.c (c_cpp_builtins_optimize_pragma): Define and
undefine __NO_MATH_ERRNO__ based on changes to -fmath-errno state.
testsuite:
* gcc.dg/no-math-errno-1.c, gcc.dg/no-math-errno-2.c,
gcc.dg/no-math-errno-3.c, gcc.dg/no-math-errno-4.c: New tests.
From-SVN: r217420
Diffstat (limited to 'gcc/cppbuiltin.c')
-rw-r--r-- | gcc/cppbuiltin.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/gcc/cppbuiltin.c b/gcc/cppbuiltin.c index 3fc2f8a..474f724 100644 --- a/gcc/cppbuiltin.c +++ b/gcc/cppbuiltin.c @@ -102,6 +102,8 @@ define_builtin_macros_for_compilation_flags (cpp_reader *pfile) cpp_define (pfile, "__FAST_MATH__"); if (flag_signaling_nans) cpp_define (pfile, "__SUPPORT_SNAN__"); + if (!flag_errno_math) + cpp_define (pfile, "__NO_MATH_ERRNO__"); cpp_define_formatted (pfile, "__FINITE_MATH_ONLY__=%d", flag_finite_math_only); |