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authorFlorian Weimer <fweimer@redhat.com>2016-10-21 18:26:53 +0200
committerFlorian Weimer <fweimer@redhat.com>2016-10-21 18:26:53 +0200
commitb3918c44db615637b26d919ce599cd86592316b3 (patch)
tree23c031ee3aaf2e2fccce583920cafb40eacdce3f /math
parent0f04fc07f6a36e761ec76100043798ea5c7a590c (diff)
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math: Define iszero as a function template for C++ [BZ #20715]
This increases compatibility with C++ code which is forced to compile with _GNU_SOURCE.
Diffstat (limited to 'math')
-rw-r--r--math/Makefile3
-rw-r--r--math/math.h24
-rw-r--r--math/test-math-iszero.cc87
3 files changed, 108 insertions, 6 deletions
diff --git a/math/Makefile b/math/Makefile
index 2aa6a34..7cecba5 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -165,7 +165,7 @@ tests-static = test-fpucw-static test-fpucw-ieee-static \
test-signgam-ullong-static test-signgam-ullong-init-static
ifneq (,$(CXX))
-tests += test-math-isinff
+tests += test-math-isinff test-math-iszero
endif
ifneq (no,$(PERL))
@@ -267,6 +267,7 @@ CFLAGS-test-signgam-ullong-static.c = -std=c99
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-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 880b4a0..0220d08 100644
--- a/math/math.h
+++ b/math/math.h
@@ -335,11 +335,25 @@ enum
# define issubnormal(x) (fpclassify (x) == FP_SUBNORMAL)
/* Return nonzero value if X is zero. */
-# ifdef __SUPPORT_SNAN__
-# define iszero(x) (fpclassify (x) == FP_ZERO)
-# else
-# define iszero(x) (((__typeof (x)) (x)) == 0)
-# endif
+# ifndef __cplusplus
+# ifdef __SUPPORT_SNAN__
+# define iszero(x) (fpclassify (x) == FP_ZERO)
+# else
+# define iszero(x) (((__typeof (x)) (x)) == 0)
+# endif
+# else /* __cplusplus */
+__END_DECLS
+template <class __T> inline bool
+iszero (__T __val)
+{
+# ifdef __SUPPORT_SNAN__
+ return fpclassify (__val) == FP_ZERO;
+# else
+ return __val == 0;
+# endif
+}
+__BEGIN_DECLS
+# endif /* __cplusplus */
#endif /* Use IEC_60559_BFP_EXT. */
#ifdef __USE_MISC
diff --git a/math/test-math-iszero.cc b/math/test-math-iszero.cc
new file mode 100644
index 0000000..5de251a
--- /dev/null
+++ b/math/test-math-iszero.cc
@@ -0,0 +1,87 @@
+/* Test for the C++ implementation of iszero.
+ Copyright (C) 2016 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>
+
+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 (iszero (T{}), 1);
+ CHECK (iszero (T{0}), 1);
+ CHECK (iszero (T{-0.0}), 1);
+ CHECK (iszero (T{1}), 0);
+ CHECK (iszero (T{-1}), 0);
+ CHECK (iszero (limits::min ()), 0);
+ CHECK (iszero (-limits::min ()), 0);
+ CHECK (iszero (limits::max ()), 0);
+ CHECK (iszero (-limits::max ()), 0);
+ if (limits::has_infinity)
+ {
+ CHECK (iszero (limits::infinity ()), 0);
+ CHECK (iszero (-limits::infinity ()), 0);
+ }
+ CHECK (iszero (limits::epsilon ()), 0);
+ CHECK (iszero (-limits::epsilon ()), 0);
+ if (limits::has_quiet_NaN)
+ CHECK (iszero (limits::quiet_NaN ()), 0);
+ if (limits::has_signaling_NaN)
+ CHECK (iszero (limits::signaling_NaN ()), 0);
+ if (limits::has_signaling_NaN)
+ CHECK (iszero (limits::signaling_NaN ()), 0);
+ CHECK (iszero (limits::denorm_min ()),
+ std::numeric_limits<T>::has_denorm == std::denorm_absent);
+ CHECK (iszero (-limits::denorm_min ()),
+ std::numeric_limits<T>::has_denorm == std::denorm_absent);
+}
+
+static int
+do_test (void)
+{
+ check_type<float> ();
+ check_type<double> ();
+#ifndef NO_LONG_DOUBLE
+ check_type<long double> ();
+#endif
+ return errors;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"