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| author | Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com> | 2017-08-14 13:46:15 -0300 |
|---|---|---|
| committer | Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com> | 2017-08-22 10:05:41 -0300 |
| commit | a16e8bc08edca84d507715c66d6cddbbc7ed3b62 (patch) | |
| tree | f997f9780b600a0da3f0456162cc2405a0b19b1e /math/math.h | |
| parent | 8d2ec553295a16ca94fe0285d6307e3b00a402d6 (diff) | |
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Provide a C++ version of issignaling that does not use __MATH_TG
The macro __MATH_TG contains the logic to select between long double and
_Float128, when these types are ABI-distinct. This logic relies on
__builtin_types_compatible_p, which is not available in C++ mode.
On the other hand, C++ function overloading provides the means to
distinguish between the floating-point types. The overloading
resolution will match the correct parameter regardless of type
qualifiers, i.e.: const and volatile.
Tested for powerpc64le, s390x, and x86_64.
* math/math.h [defined __cplusplus] (issignaling): Provide a C++
definition for issignaling that does not rely on __MATH_TG,
since __MATH_TG uses __builtin_types_compatible_p, which is only
available in C mode.
(CFLAGS-test-math-issignaling.cc): New variable.
* math/Makefile [CXX] (tests): Add test-math-issignaling.
* math/test-math-issignaling.cc: New test for C++ implementation
of type-generic issignaling.
* sysdeps/powerpc/powerpc64le/Makefile [subdir == math]
(CXXFLAGS-test-math-issignaling.cc): Add -mfloat128 to the build
options of test-math-issignaling on powerpc64le.
Diffstat (limited to 'math/math.h')
| -rw-r--r-- | math/math.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/math/math.h b/math/math.h index 275534be11..b5d6c43fcf 100644 --- a/math/math.h +++ b/math/math.h @@ -474,7 +474,24 @@ enum # include <bits/iscanonical.h> /* Return nonzero value if X is a signaling NaN. */ -# define issignaling(x) __MATH_TG ((x), __issignaling, (x)) +# ifndef __cplusplus +# define issignaling(x) __MATH_TG ((x), __issignaling, (x)) +# else + /* In C++ mode, __MATH_TG cannot be used, because it relies on + __builtin_types_compatible_p, which is a C-only builtin. On the + other hand, overloading provides the means to distinguish between + the floating-point types. The overloading resolution will match + the correct parameter (regardless of type qualifiers (i.e.: const + and volatile). */ +extern "C++" { +inline int issignaling (float __val) { return __issignalingf (__val); } +inline int issignaling (double __val) { return __issignaling (__val); } +inline int issignaling (long double __val) { return __issignalingl (__val); } +# if __HAVE_DISTINCT_FLOAT128 +inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); } +# endif +} /* extern C++ */ +# endif /* Return nonzero value if X is subnormal. */ # define issubnormal(x) (fpclassify (x) == FP_SUBNORMAL) |