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authorGabriel F. T. Gomes <gabriel@inconstante.eti.br>2017-11-03 10:44:36 -0200
committerGabriel F. T. Gomes <gabriel@inconstante.eti.br>2017-12-19 23:26:59 -0200
commitc85e54ac6cef0faed7b7ffc722f52523dec59bf5 (patch)
tree594a7a95e759e7035ee80ea0dee46b09f917f9aa /math
parent10e93d968716ab82931d593bada121c17c0a4b93 (diff)
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Provide a C++ version of iseqsig (bug 22377)
In C++ mode, __MATH_TG cannot be used for defining iseqsig, because __MATH_TG relies on __builtin_types_compatible_p, which is a C-only builtin. This is true when float128 is provided as an ABI-distinct type from long double. Moreover, the comparison macros from ISO C take two floating-point arguments, which need not have the same type. Choosing what underlying function to call requires evaluating the formats of the arguments, then selecting which is wider. The macro __MATH_EVAL_FMT2 provides this information, however, only the type of the macro expansion is relevant (actually evaluating the expression would be incorrect). This patch provides a C++ version of iseqsig, in which only the type of __MATH_EVAL_FMT2 (__typeof or decltype) is used as a template parameter for __iseqsig_type. This function calls the appropriate underlying function. Tested for powerpc64le and x86_64. [BZ #22377] * math/Makefile [C++] (tests): Add test for iseqsig. * math/math.h [C++] (iseqsig): New implementation, which does not rely on __MATH_TG/__builtin_types_compatible_p. * math/test-math-iseqsig.cc: New file. * sysdeps/powerpc/powerpc64le/Makefile (CFLAGS-test-math-iseqsig.cc): New variable.
Diffstat (limited to 'math')
-rw-r--r--math/Makefile2
-rw-r--r--math/math.h72
-rw-r--r--math/test-math-iseqsig.cc111
3 files changed, 182 insertions, 3 deletions
diff --git a/math/Makefile b/math/Makefile
index cba9ce9..8978f2e 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -220,7 +220,7 @@ tests-static += atest-exp atest-sincos atest-exp2
ifneq (,$(CXX))
tests += test-math-isinff test-math-iszero test-math-issignaling \
- test-math-iscanonical test-math-cxx11
+ test-math-iscanonical test-math-cxx11 test-math-iseqsig
endif
ifneq (no,$(PERL))
diff --git a/math/math.h b/math/math.h
index f6d1fee..72d7dc5 100644
--- a/math/math.h
+++ b/math/math.h
@@ -1182,8 +1182,76 @@ iszero (__T __val)
/* Return X == Y but raising "invalid" and setting errno if X or Y is
a NaN. */
-# define iseqsig(x, y) \
- __MATH_TG (__MATH_EVAL_FMT2 (x, y), __iseqsig, ((x), (y)))
+# if !defined __cplusplus || (__cplusplus < 201103L && !defined __GNUC__)
+# define iseqsig(x, y) \
+ __MATH_TG (__MATH_EVAL_FMT2 (x, y), __iseqsig, ((x), (y)))
+# else
+/* In C++ mode, __MATH_TG cannot be used, because it relies on
+ __builtin_types_compatible_p, which is a C-only builtin. Moreover,
+ the comparison macros from ISO C take two floating-point arguments,
+ which need not have the same type. Choosing what underlying function
+ to call requires evaluating the formats of the arguments, then
+ selecting which is wider. The macro __MATH_EVAL_FMT2 provides this
+ information, however, only the type of the macro expansion is
+ relevant (actually evaluating the expression would be incorrect).
+ Thus, the type is used as a template parameter for __iseqsig_type,
+ which calls the appropriate underlying function. */
+extern "C++" {
+template<typename> struct __iseqsig_type;
+
+template<> struct __iseqsig_type<float>
+{
+ static int __call (float __x, float __y) throw ()
+ {
+ return __iseqsigf (__x, __y);
+ }
+};
+
+template<> struct __iseqsig_type<double>
+{
+ static int __call (double __x, double __y) throw ()
+ {
+ return __iseqsig (__x, __y);
+ }
+};
+
+template<> struct __iseqsig_type<long double>
+{
+ static int __call (double __x, double __y) throw ()
+ {
+# ifndef __NO_LONG_DOUBLE_MATH
+ return __iseqsigl (__x, __y);
+# else
+ return __iseqsig (__x, __y);
+# endif
+ }
+};
+
+# if __HAVE_DISTINCT_FLOAT128
+template<> struct __iseqsig_type<_Float128>
+{
+ static int __call (_Float128 __x, _Float128 __y) throw ()
+ {
+ return __iseqsigf128 (__x, __y);
+ }
+};
+# endif
+
+template<typename _T1, typename _T2>
+inline int
+iseqsig (_T1 __x, _T2 __y) throw ()
+{
+# if __cplusplus >= 201103L
+ typedef decltype (__MATH_EVAL_FMT2 (__x, __y)) _T3;
+# else
+ typedef __typeof (__MATH_EVAL_FMT2 (__x, __y)) _T3;
+# endif
+ return __iseqsig_type<_T3>::__call (__x, __y);
+}
+
+} /* extern "C++" */
+# endif /* __cplusplus */
+
#endif
__END_DECLS
diff --git a/math/test-math-iseqsig.cc b/math/test-math-iseqsig.cc
new file mode 100644
index 0000000..48e8f1e
--- /dev/null
+++ b/math/test-math-iseqsig.cc
@@ -0,0 +1,111 @@
+/* Test for the C++ implementation of iseqsig.
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#define _GNU_SOURCE 1
+#include <math.h>
+#include <stdio.h>
+
+#include <limits>
+
+/* There is no 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 NaN. */
+#if __HAVE_DISTINCT_FLOAT128
+# include <ieee754_float128.h>
+#endif
+
+#include <support/check.h>
+
+static void
+check (int actual, int expected, const char *actual_expr, int line)
+{
+ if (actual != expected)
+ {
+ support_record_failure ();
+ 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 <class T1, class T2>
+static void
+check_type ()
+{
+ T1 t1 = 0;
+ T2 t2 = 0;
+ CHECK (iseqsig (t1, t2), 1);
+
+ t2 = 1;
+ CHECK (iseqsig (t1, t2), 0);
+
+ if (std::numeric_limits<T1>::has_quiet_NaN
+ && std::numeric_limits<T2>::has_quiet_NaN)
+ {
+ CHECK (iseqsig (std::numeric_limits<T1>::quiet_NaN (), t2), 0);
+ CHECK (iseqsig (t1, std::numeric_limits<T2>::quiet_NaN ()), 0);
+ CHECK (iseqsig (std::numeric_limits<T1>::quiet_NaN (),
+ std::numeric_limits<T2>::quiet_NaN ()), 0);
+ }
+}
+
+#if __HAVE_DISTINCT_FLOAT128
+static void
+check_float128 ()
+{
+ ieee854_float128 q1, q2, q3_nan;
+
+ q1.d = 0;
+ q2.d = 1;
+ q3_nan.ieee_nan.negative = 0;
+ q3_nan.ieee_nan.exponent = 0x7FFF;
+ q3_nan.ieee_nan.quiet_nan = 1;
+ q3_nan.ieee_nan.mantissa0 = 0x0000;
+ q3_nan.ieee_nan.mantissa1 = 0x00000000;
+ q3_nan.ieee_nan.mantissa2 = 0x00000000;
+ q3_nan.ieee_nan.mantissa3 = 0x00000000;
+
+ CHECK (iseqsig (q1.d, q1.d), 1);
+ CHECK (iseqsig (q1.d, q2.d), 0);
+ CHECK (iseqsig (q1.d, q3_nan.d), 0);
+ CHECK (iseqsig (q3_nan.d, q3_nan.d), 0);
+}
+#endif
+
+static int
+do_test (void)
+{
+ check_type<float, float> ();
+ check_type<float, double> ();
+ check_type<float, long double> ();
+ check_type<double, float> ();
+ check_type<double, double> ();
+ check_type<double, long double> ();
+ check_type<long double, float> ();
+ check_type<long double, double> ();
+ check_type<long double, long double> ();
+#if __HAVE_DISTINCT_FLOAT128
+ check_float128 ();
+#endif
+ return 0;
+}
+
+#include <support/test-driver.c>