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| author | Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com> | 2017-08-22 16:34:42 -0300 |
|---|---|---|
| committer | Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com> | 2017-08-28 15:22:37 -0300 |
| commit | 42496114ec0eb7d6d039d05d4262e109951c600c (patch) | |
| tree | 02ff0c29ba5887cbd6fe2171015c339500574270 /math/math.h | |
| parent | 56bc7f43603b5d28437496efb32df40997c62cb4 (diff) | |
Provide a C++ version of iszero that does not use __MATH_TG (bug 21930)
When signaling nans are enabled (with -fsignaling-nans), the C++ version
of iszero uses the fpclassify macro, which is defined with __MATH_TG.
However, when support for float128 is available, __MATH_TG uses the
builtin __builtin_types_compatible_p, which is only available in C mode.
This patch refactors the C++ version of iszero so that it uses function
overloading to select between the floating-point types, instead of
relying on fpclassify and __MATH_TG.
Tested for powerpc64le, s390x, x86_64, and with build-many-glibcs.py.
[BZ #21930]
* math/math.h [defined __cplusplus && defined __SUPPORT_SNAN__]
(iszero): New C++ implementation that does not use
fpclassify/__MATH_TG/__builtin_types_compatible_p, when
signaling nans are enabled, since __builtin_types_compatible_p
is a C-only feature.
* math/test-math-iszero.cc: When __HAVE_DISTINCT_FLOAT128 is
defined, include ieee754_float128.h for access to the union and
member ieee854_float128.ieee.
[__HAVE_DISTINCT_FLOAT128] (do_test): Call check_float128.
[__HAVE_DISTINCT_FLOAT128] (check_float128): New function.
* sysdeps/powerpc/powerpc64le/Makefile [subdir == math]
(CXXFLAGS-test-math-iszero.cc): Add -mfloat128 to the build
options of test-math-zero on powerpc64le.
Diffstat (limited to 'math/math.h')
| -rw-r--r-- | math/math.h | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/math/math.h b/math/math.h index 9162bee50c..f3eb677a40 100644 --- a/math/math.h +++ b/math/math.h @@ -513,15 +513,40 @@ inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); } # endif # else /* __cplusplus */ extern "C++" { +# ifdef __SUPPORT_SNAN__ +inline int +iszero (float __val) +{ + return __fpclassifyf (__val) == FP_ZERO; +} +inline int +iszero (double __val) +{ + return __fpclassify (__val) == FP_ZERO; +} +inline int +iszero (long double __val) +{ +# ifdef __NO_LONG_DOUBLE_MATH + return __fpclassify (__val) == FP_ZERO; +# else + return __fpclassifyl (__val) == FP_ZERO; +# endif +} +# if __HAVE_DISTINCT_FLOAT128 +inline int +iszero (_Float128 __val) +{ + return __fpclassifyf128 (__val) == FP_ZERO; +} +# endif +# else template <class __T> inline bool iszero (__T __val) { -# ifdef __SUPPORT_SNAN__ - return fpclassify (__val) == FP_ZERO; -# else return __val == 0; -# endif } +# endif } /* extern C++ */ # endif /* __cplusplus */ #endif /* Use IEC_60559_BFP_EXT. */ |