From cc4084017e211cdeafef2d9036a130cbd6f2cadd Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Tue, 8 Mar 2016 00:27:21 +0000 Subject: Fix ldbl-128ibm remainderl equality test for zero low part (bug 19677). The ldbl-128ibm implementation of remainderl has logic resulting in incorrect tests for equality of the absolute values of the arguments in the case of zero low parts. If the low parts are both zero but with different signs, this can wrongly cause equal arguments to be treated as different, resulting in turn in incorrect signs of zero result in nondefault rounding modes arising from the subtractions done when the arguments are not equal. This patch fixes the logic to convert -0 low parts into +0 before the comparison (remquo already has separate logic to deal with signs of zero results, so doesn't need such a change). Tests are added for remainderl and remquol similar to that for fmodl, and based on a refactoring of it, since the bug depends on low parts which should not be relied upon in tests not setting the representation explicitly (although in fact the bug shows up in test-ldouble with current GCC). Tested for powerpc. [BZ #19677] * sysdeps/ieee754/ldbl-128ibm/e_remainderl.c (__ieee754_remainderl): Put zero low parts in canonical form. * sysdeps/ieee754/ldbl-128ibm/test-fmodrem-ldbl-128ibm.c: New file. Based on sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c. * sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c: Replace with wrapper round test-fmodrem-ldbl-128ibm.c. * sysdeps/ieee754/ldbl-128ibm/test-remainderl-ldbl-128ibm.c: New file. * sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add test-remainderl-ldbl-128ibm and test-remquol-ldbl-128ibm. --- .../ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c | 30 ++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c (limited to 'sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c') diff --git a/sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c b/sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c new file mode 100644 index 0000000..b691e3f --- /dev/null +++ b/sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c @@ -0,0 +1,30 @@ +/* Test for ldbl-128ibm remquol handling of equal values (bug 19677). + 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 + . */ + +#include + +static long double +wrap_remquol (long double x, long double y) +{ + int quo; + return remquol (x, y, &quo); +} + +#define FUNC wrap_remquol +#define SETUP fesetround (FE_DOWNWARD) +#include "test-fmodrem-ldbl-128ibm.c" -- cgit v1.1