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This patch fixes bug 16064, i386 fenv_t not including SSE state, using the technique suggested there of storing the state in the existing __eip field of fenv_t to avoid needing to increase the size of fenv_t and add new symbol versions. The included testcase, which previously failed for i386 (but passed for x86_64), illustrates how the previous state was buggy. This patch causes the SSE state to be included *to the extent it is on x86_64*. Where some state should logically be included but isn't for x86_64 (see bug 16068), this patch does not cause it to be included for i386 either. The idea is that any patch fixing that bug should fix it for both x86_64 and i386 at once. Tested i386 and x86_64. (I haven't tested the case of a CPU without SSE2 disabling the test.) [BZ #16064] * sysdeps/i386/fpu/fegetenv.c: Include <unistd.h>, <ldsodefs.h> and <dl-procinfo.h>. (__fegetenv): Save SSE state in envp->__eip if supported. * sysdeps/i386/fpu/feholdexcpt.c (feholdexcept): Save SSE state in envp->__eip if supported. * sysdeps/i386/fpu/fesetenv.c: Include <unistd.h>, <ldsodefs.h> and <dl-procinfo.h>. (__fesetenv): Always set __eip, __cs_selector, __opcode, __data_offset and __data_selector in environment to 0. Set SSE state if supported. * sysdeps/x86/fpu/Makefile [$(subdir) = math] (tests): Add test-fenv-sse. [$(subdir) = math] (CFLAGS-test-fenv-sse.c): Add -msse2 -mfpmath=sse. * sysdeps/x86/fpu/test-fenv-sse.c: New file.
49 lines
1.6 KiB
C
49 lines
1.6 KiB
C
/* Store current floating-point environment and clear exceptions.
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Copyright (C) 1997-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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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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#include <fenv.h>
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#include <unistd.h>
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#include <ldsodefs.h>
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#include <dl-procinfo.h>
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int
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feholdexcept (fenv_t *envp)
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{
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/* Store the environment. Recall that fnstenv has a side effect of
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masking all exceptions. Then clear all exceptions. */
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__asm__ volatile ("fnstenv %0; fnclex" : "=m" (*envp));
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/* If the CPU supports SSE we set the MXCSR as well. */
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if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
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{
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unsigned int xwork;
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/* Get the current control word. */
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__asm__ ("stmxcsr %0" : "=m" (envp->__eip));
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/* Set all exceptions to non-stop and clear them. */
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xwork = (envp->__eip | 0x1f80) & ~0x3f;
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__asm__ ("ldmxcsr %0" : : "m" (*&xwork));
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}
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return 0;
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}
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libm_hidden_def (feholdexcept)
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