From 9bcf391a21677c6d5fa1c2be71554ec181e24f39 Mon Sep 17 00:00:00 2001 From: "Gabriel F. T. Gomes" Date: Mon, 14 Aug 2017 13:46:15 -0300 Subject: [PATCH] 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. (cherry picked from commit a16e8bc08edca84d507715c66d6cddbbc7ed3b62) [Romain rebase on glibc 2.26] Signed-off-by: Romain Naour --- math/Makefile | 3 +- math/math.h | 19 +++++- math/test-math-issignaling.cc | 113 +++++++++++++++++++++++++++++++++++ sysdeps/powerpc/powerpc64le/Makefile | 1 + 4 files changed, 134 insertions(+), 2 deletions(-) create mode 100644 math/test-math-issignaling.cc diff --git a/math/Makefile b/math/Makefile index e09b0c0..0130fcf 100644 --- a/math/Makefile +++ b/math/Makefile @@ -203,7 +203,7 @@ tests-static = test-fpucw-static test-fpucw-ieee-static \ test-signgam-ullong-static test-signgam-ullong-init-static ifneq (,$(CXX)) -tests += test-math-isinff test-math-iszero +tests += test-math-isinff test-math-iszero test-math-issignaling endif ifneq (no,$(PERL)) @@ -350,6 +350,7 @@ CFLAGS-test-signgam-ullong-init-static.c = -std=c99 CFLAGS-test-math-isinff.cc = -std=gnu++11 CFLAGS-test-math-iszero.cc = -std=gnu++11 +CFLAGS-test-math-issignaling.cc = -std=gnu++11 CFLAGS-test-iszero-excess-precision.c = -fexcess-precision=standard CFLAGS-test-iseqsig-excess-precision.c = -fexcess-precision=standard diff --git a/math/math.h b/math/math.h index dea8dbe..add86af 100644 --- a/math/math.h +++ b/math/math.h @@ -474,7 +474,24 @@ enum # include /* 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) diff --git a/math/test-math-issignaling.cc b/math/test-math-issignaling.cc new file mode 100644 index 0000000..22ae9e1 --- /dev/null +++ b/math/test-math-issignaling.cc @@ -0,0 +1,113 @@ +/* Test for the C++ implementation of issignaling. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#define _GNU_SOURCE 1 +#include +#include + +#include + +/* There is no signaling_NaN for _Float128 in std::numeric_limits. + Include ieee754_float128.h and use the bitfields in the union + ieee854_float128.ieee_nan to build a signaling NaN. */ +#if __HAVE_DISTINCT_FLOAT128 +# include +#endif + +static bool errors; + +static void +check (int actual, int expected, const char *actual_expr, int line) +{ + if (actual != expected) + { + errors = true; + printf ("%s:%d: error: %s\n", __FILE__, line, actual_expr); + printf ("%s:%d: expected: %d\n", __FILE__, line, expected); + printf ("%s:%d: actual: %d\n", __FILE__, line, actual); + } +} + +#define CHECK(actual, expected) \ + check ((actual), (expected), #actual, __LINE__) + +template +static void +check_type () +{ + typedef std::numeric_limits limits; + CHECK (issignaling (T{0}), 0); + if (limits::has_infinity) + { + CHECK (issignaling (limits::infinity ()), 0); + CHECK (issignaling (-limits::infinity ()), 0); + } + if (limits::has_quiet_NaN) + CHECK (issignaling (limits::quiet_NaN ()), 0); + if (limits::has_signaling_NaN) + CHECK (issignaling (limits::signaling_NaN ()), 1); +} + +#if __HAVE_DISTINCT_FLOAT128 +static void +check_float128 () +{ + ieee854_float128 q; + + q.d = 0; + CHECK (issignaling (q.d), 0); + + /* Infinity. */ + q.ieee.negative = 0; + q.ieee.exponent = 0x7FFF; + q.ieee.mantissa0 = 0x0000; + q.ieee.mantissa1 = 0x00000000; + q.ieee.mantissa2 = 0x00000000; + q.ieee.mantissa3 = 0x00000000; + CHECK (issignaling (q.d), 0); + + /* Quiet NaN. */ + q.ieee_nan.quiet_nan = 1; + q.ieee_nan.mantissa0 = 0x0000; + CHECK (issignaling (q.d), 0); + + /* Still a quiet NaN. */ + q.ieee_nan.quiet_nan = 1; + q.ieee_nan.mantissa0 = 0x4000; + CHECK (issignaling (q.d), 0); + + /* Signaling NaN. */ + q.ieee_nan.quiet_nan = 0; + q.ieee_nan.mantissa0 = 0x4000; + CHECK (issignaling (q.d), 1); +} +#endif + +static int +do_test (void) +{ + check_type (); + check_type (); + check_type (); +#if __HAVE_DISTINCT_FLOAT128 + check_float128 (); +#endif + return errors; +} + +#include diff --git a/sysdeps/powerpc/powerpc64le/Makefile b/sysdeps/powerpc/powerpc64le/Makefile index 77617b6..19adbfa 100644 --- a/sysdeps/powerpc/powerpc64le/Makefile +++ b/sysdeps/powerpc/powerpc64le/Makefile @@ -16,6 +16,7 @@ $(foreach suf,$(all-object-suffixes),%f128_r$(suf)): CFLAGS += -mfloat128 $(foreach suf,$(all-object-suffixes),$(objpfx)test-float128%$(suf)): CFLAGS += -mfloat128 $(foreach suf,$(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%: \ gnulib-tests += $(f128-loader-link) endif -- 2.9.5