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authorGabriel F. T. Gomes <gftg@linux.vnet.ibm.com>2017-08-14 13:46:15 -0300
committerGabriel F. T. Gomes <gftg@linux.vnet.ibm.com>2017-08-22 10:05:41 -0300
commita16e8bc08edca84d507715c66d6cddbbc7ed3b62 (patch)
treef997f9780b600a0da3f0456162cc2405a0b19b1e /math
parent8d2ec553295a16ca94fe0285d6307e3b00a402d6 (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')
-rw-r--r--math/Makefile3
-rw-r--r--math/math.h19
-rw-r--r--math/test-math-issignaling.cc113
3 files changed, 133 insertions, 2 deletions
diff --git a/math/Makefile b/math/Makefile
index fb79b80..9e88cfc 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -208,7 +208,7 @@ tests-internal = test-matherr test-matherr-2
tests-static += atest-exp atest-sincos atest-exp2
ifneq (,$(CXX))
-tests += test-math-isinff test-math-iszero
+tests += test-math-isinff test-math-iszero test-math-issignaling
endif
ifneq (no,$(PERL))
@@ -355,6 +355,7 @@ 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 275534b..b5d6c43 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)
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
+ <http://www.gnu.org/licenses/>. */
+
+#define _GNU_SOURCE 1
+#include <math.h>
+#include <stdio.h>
+
+#include <limits>
+
+/* 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 <ieee754_float128.h>
+#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 <class T>
+static void
+check_type ()
+{
+ typedef std::numeric_limits<T> 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<float> ();
+ check_type<double> ();
+ check_type<long double> ();
+#if __HAVE_DISTINCT_FLOAT128
+ check_float128 ();
+#endif
+ return errors;
+}
+
+#include <support/test-driver.c>