mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 12:11:10 +00:00
b59ad2db99
Floating-point classification macros are supposed to remove any excess range or precision from their arguments. This patch fixes the non-sNaN version of iszero to do so, by casting the argument to its own type. (This will of course work only for standard-conforming excess precision, not for what GCC does on 32-bit x86 by default where the back end hides excess precision from the front end; the same applies to most of the classification macros in that case, as showed up when we made them use GCC built-in functions.) (iseqsig will have the reverse issue, needing to ensure that when an underlying function is used it's for a type wide enough not to remove any excess precision, since comparison macros must not remove excess precision.) Tested for x86_64 and x86. * math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT) && !__SUPPORT_SNAN__] (iszero): Cast argument to its own type. * math/test-iszero-excess-precision.c: New file. * math/Makefile (tests): Add test-iszero-excess-precision. (CFLAGS-test-iszero-excess-precision.c): New variable.
50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
/* Test iszero with excess precision.
|
|
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/>. */
|
|
|
|
#include <float.h>
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
|
|
#define TEST(TYPE, TRUE_MIN) \
|
|
do \
|
|
{ \
|
|
if (iszero (TRUE_MIN / 2)) \
|
|
puts ("iszero removes excess precision for " #TYPE); \
|
|
else \
|
|
{ \
|
|
puts ("iszero fails to remove excess precision for " #TYPE); \
|
|
result = 1; \
|
|
} \
|
|
} \
|
|
while (0)
|
|
|
|
static int
|
|
do_test (void)
|
|
{
|
|
int result = 0;
|
|
|
|
TEST (float, FLT_TRUE_MIN);
|
|
TEST (double, DBL_TRUE_MIN);
|
|
TEST (long double, LDBL_TRUE_MIN);
|
|
|
|
return result;
|
|
}
|
|
|
|
#define TEST_FUNCTION do_test ()
|
|
#include "../test-skeleton.c"
|