glibc/math/test-nearbyint-except.c

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Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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/* Test nearbyint functions do not clear exceptions (bug 15491).
Copyright (C) 2015-2019 Free Software Foundation, Inc.
Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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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 <fenv.h>
#include <math.h>
#include <stdbool.h>
Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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#include <stdio.h>
#include <math-tests.h>
#ifndef FE_INVALID
# define FE_INVALID 0
#endif
static bool any_supported = false;
Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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#define TEST_FUNC(NAME, FLOAT, SUFFIX) \
static int \
NAME (void) \
{ \
int result = 0; \
if (!EXCEPTION_TESTS (FLOAT)) \
return 0; \
any_supported = true; \
Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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volatile FLOAT a, b __attribute__ ((unused)); \
a = 1.0; \
/* nearbyint must not clear already-raised exceptions. */ \
feraiseexcept (FE_ALL_EXCEPT); \
b = nearbyint ## SUFFIX (a); \
if (fetestexcept (FE_ALL_EXCEPT) == FE_ALL_EXCEPT) \
puts ("PASS: " #FLOAT); \
else \
{ \
puts ("FAIL: " #FLOAT); \
result = 1; \
} \
/* But it mustn't lose exceptions from sNaN arguments. */ \
if (SNAN_TESTS (FLOAT)) \
Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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{ \
static volatile FLOAT snan = __builtin_nans ## SUFFIX (""); \
volatile FLOAT c __attribute__ ((unused)); \
feclearexcept (FE_ALL_EXCEPT); \
c = nearbyint ## SUFFIX (snan); \
if (fetestexcept (FE_INVALID) == FE_INVALID) \
puts ("PASS: " #FLOAT " sNaN"); \
else \
{ \
puts ("FAIL: " #FLOAT " sNaN"); \
result = 1; \
} \
} \
return result; \
}
TEST_FUNC (float_test, float, f)
TEST_FUNC (double_test, double, )
TEST_FUNC (ldouble_test, long double, l)
static int
do_test (void)
{
int result = float_test ();
result |= double_test ();
result |= ldouble_test ();
if (!any_supported)
return 77;
Fix i386 / x86_64 nearbyint exception clearing (bug 15491). The implementations of nearbyint functions using x87 floating point (i386 all versions, x86_64 long double only) use the fclex instruction, which clears any exceptions that were raised before the function was called. These functions must not clear exceptions that were raised before they were called. This patch fixes these functions to save and restore the whole floating-point environment (fnstenv / fldenv) as the way of avoiding raising "inexact" (recall that there isn't an x87 instruction for loading just the status word, so the whole environment has to be saved and loaded instead - the code already saved and loaded the control word, which is now obtained from the saved environment after this patch, to disable traps on "inexact"). In the case of the long double functions, any "invalid" exception from frndint (applied to a signaling NaN) needs merging into the saved state; this issue doesn't apply to the float and double functions because that exception would have been raised when the argument is loaded, before the environment is saved. [BZ #15491] * sysdeps/i386/fpu/s_nearbyint.S (__nearbyint): Save and restore floating-point environment instead of clearing all exceptions. * sysdeps/i386/fpu/s_nearbyintf.S (__nearbyintf): Likewise. * sysdeps/i386/fpu/s_nearbyintl.S (__nearbyintl): Likewise, merging in "invalid" exceptions from frndint. * sysdeps/x86_64/fpu/s_nearbyintl.S (__nearbyintl): Likewise. * math/test-nearbyint-except.c: New file. * math/Makefile (tests): Add test-nearbyint-except.
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return result;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"