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8b1bab5ffa
__kernel_standard_l converts long double arguments to double for use in SVID "struct exception". This has special-case handling for when that conversion would overflow or underflow but the original long double function wouldn't. However, it turns out that "inexact" exceptions can be spurious here as well, when the function is exactly determined and __kernel_standard_l is being called for a domain error. This patch fixes this by using feholdexcept / fesetenv to avoid exceptions from the conversion, replacing the previous special-case logic for overflow and underflow (this covers all functions using __kernel_standard_l, not just those that actually need a change, since there doesn't seem to be much point in restricting things just to the functions that mustn't get "inexact" here). Tested for x86_64 and x86. [BZ #18245] [BZ #18583] * sysdeps/ieee754/k_standardl.c: Include <fenv.h>. (__kernel_standard_l): Use feholdexcept and fesetenv around conversion to double instead of special-casing overflow and underflow. * math/libm-test.inc (fmod_test_data): Add more tests. (remainder_test_data): Likewise. (sqrt_test_data): Likewise.
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/* Implement __kernel_standard_l.
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Copyright (C) 2012-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>.
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Parts based on k_standard.c from fdlibm: */
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/* @(#)k_standard.c 5.1 93/09/24 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <math.h>
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#include <math_private.h>
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#include <fenv.h>
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#include <float.h>
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#include <errno.h>
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static double zero = 0.0;
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/* Handle errors for a libm function as specified by TYPE (see
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comments in k_standard.c for details), with arguments X and Y,
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returning the appropriate return value for that function. */
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long double
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__kernel_standard_l (long double x, long double y, int type)
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{
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double dx, dy;
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struct exception exc;
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fenv_t env;
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feholdexcept (&env);
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dx = x;
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dy = y;
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math_force_eval (dx);
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math_force_eval (dy);
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fesetenv (&env);
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switch (type)
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{
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case 221:
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/* powl (x, y) overflow. */
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exc.arg1 = dx;
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exc.arg2 = dy;
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exc.type = OVERFLOW;
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exc.name = (char *) "powl";
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if (_LIB_VERSION == _SVID_)
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{
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exc.retval = HUGE;
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y *= 0.5;
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if (x < zero && __rintl (y) != y)
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exc.retval = -HUGE;
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}
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else
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{
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exc.retval = HUGE_VAL;
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y *= 0.5;
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if (x < zero && __rintl (y) != y)
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exc.retval = -HUGE_VAL;
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}
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if (_LIB_VERSION == _POSIX_)
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__set_errno (ERANGE);
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else if (!matherr (&exc))
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__set_errno (ERANGE);
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return exc.retval;
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case 222:
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/* powl (x, y) underflow. */
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exc.arg1 = dx;
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exc.arg2 = dy;
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exc.type = UNDERFLOW;
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exc.name = (char *) "powl";
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exc.retval = zero;
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y *= 0.5;
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if (x < zero && __rintl (y) != y)
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exc.retval = -zero;
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if (_LIB_VERSION == _POSIX_)
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__set_errno (ERANGE);
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else if (!matherr (&exc))
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__set_errno (ERANGE);
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return exc.retval;
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default:
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return __kernel_standard (dx, dy, type);
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}
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}
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