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authorGabriel F. T. Gomes <gftg@linux.vnet.ibm.com>2017-08-22 16:34:42 -0300
committerGabriel F. T. Gomes <gftg@linux.vnet.ibm.com>2017-08-28 15:22:37 -0300
commit42496114ec0eb7d6d039d05d4262e109951c600c (patch)
tree02ff0c29ba5887cbd6fe2171015c339500574270 /sysdeps
parent56bc7f43603b5d28437496efb32df40997c62cb4 (diff)
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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 'sysdeps')
-rw-r--r--sysdeps/powerpc/powerpc64le/Makefile3
1 files changed, 2 insertions, 1 deletions
diff --git a/sysdeps/powerpc/powerpc64le/Makefile b/sysdeps/powerpc/powerpc64le/Makefile
index 19adbfa1c1..dea2290736 100644
--- a/sysdeps/powerpc/powerpc64le/Makefile
+++ b/sysdeps/powerpc/powerpc64le/Makefile
@@ -17,7 +17,8 @@ $(foreach suf,$(all-object-suffixes),$(objpfx)test-float128%$(suf)): CFLAGS += -
 $(foreach suf,$(all-object-suffixes),$(objpfx)test-ifloat128%$(suf)): CFLAGS += -mfloat128
 CFLAGS-libm-test-support-float128.c += -mfloat128
 CFLAGS-test-math-issignaling.cc += -mfloat128
-$(objpfx)test-float128% $(objpfx)test-ifloat128%: \
+CFLAGS-test-math-iszero.cc += -mfloat128
+$(objpfx)test-float128% $(objpfx)test-ifloat128% $(objpfx)test-math-iszero: \
   gnulib-tests += $(f128-loader-link)
 endif