964b8cc0b2
fedisableexcept(), and fegetexcept(). These two sets of routines provide the same functionality. I implemented the former as an undocumented internal interface to make the regression test easier to write. However, fe(enable|disable|get)except() is already part of glibc, and I would like to avoid gratuitous differences. The only major flaw in the glibc API is that there's no good way to report errors on processors that don't support all the unmasked exceptions.
145 lines
3.5 KiB
C
145 lines
3.5 KiB
C
/*-
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* Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/cdefs.h>
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#include <machine/sysarch.h>
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#include <fenv.h>
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const fenv_t __fe_dfl_env = 0x680e000000000000ULL;
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struct mask_args {
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fenv_t mask;
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};
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/*
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* The lower 49 bits of the FPCR are unused by the hardware, so we use
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* the lower order bits to store the kernel's idea of the FP mask as
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* described in the Alpha Architecture Manual.
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*/
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int
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fegetenv(fenv_t *envp)
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{
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struct mask_args p;
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union __fpcr r;
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/*
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* The syscall acts as an implicit exception barrier, so we
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* only need to issue an excb after the mf_fpcr to ensure that
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* the read is executed before any subsequent FP ops.
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*/
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sysarch(ALPHA_GET_FPMASK, (char *)&p);
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__mf_fpcr(&r.__d);
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*envp = r.__bits | p.mask;
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__excb();
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return (0);
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}
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int
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feholdexcept(fenv_t *envp)
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{
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struct mask_args p;
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union __fpcr r;
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sysarch(ALPHA_GET_FPMASK, (char *)&p);
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__mf_fpcr(&r.__d);
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*envp = r.__bits | p.mask;
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r.__bits &= ~((fenv_t)FE_ALL_EXCEPT << _FPUSW_SHIFT);
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__mt_fpcr(r.__d);
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if (p.mask & FE_ALL_EXCEPT) {
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p.mask = 0;
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sysarch(ALPHA_SET_FPMASK, &p);
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}
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__excb();
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return (0);
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}
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int
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fesetenv(const fenv_t *envp)
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{
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struct mask_args p;
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union __fpcr r;
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p.mask = *envp & FE_ALL_EXCEPT;
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sysarch(ALPHA_SET_FPMASK, &p);
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r.__bits = *envp & ~FE_ALL_EXCEPT;
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__mt_fpcr(r.__d);
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__excb();
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return (0);
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}
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int
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feupdateenv(const fenv_t *envp)
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{
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struct mask_args p;
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union __fpcr oldr, newr;
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p.mask = *envp & FE_ALL_EXCEPT;
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sysarch(ALPHA_SET_FPMASK, &p);
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__mf_fpcr(&oldr.__d);
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newr.__bits = *envp & ~FE_ALL_EXCEPT;
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__excb();
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__mt_fpcr(newr.__d);
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feraiseexcept((oldr.__bits >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
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return (0);
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}
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int
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__feenableexcept(int mask)
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{
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struct mask_args p;
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sysarch(ALPHA_GET_FPMASK, &p);
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p.mask |= (mask & FE_ALL_EXCEPT);
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sysarch(ALPHA_SET_FPMASK, &p);
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return (p.mask);
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}
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int
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__fedisableexcept(int mask)
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{
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struct mask_args p;
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sysarch(ALPHA_GET_FPMASK, &p);
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p.mask &= ~(mask & FE_ALL_EXCEPT);
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sysarch(ALPHA_SET_FPMASK, &p);
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return (p.mask);
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}
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int
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__fegetexcept(void)
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{
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struct mask_args p;
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sysarch(ALPHA_GET_FPMASK, &p);
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return (p.mask);
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}
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__weak_reference(__feenableexcept, feenableexcept);
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__weak_reference(__fedisableexcept, fedisableexcept);
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__weak_reference(__fegetexcept, fegetexcept);
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