arch/i386-all/stdc/fenv.c

   1 /*-
   2  * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/lib/msun/i387/fenv.c,v 1.3 2007/01/05 07:15:26 das Exp $
  27  */
  28
  29 #define __BSD_VISIBLE 1
  30 #include "fenv.h"
  31
  32 #define __INITIAL_FPUCW_I386__  0x127F
  33 #define __INITIAL_NPXCW__       __INITIAL_FPUCW_I386__
  34
  35 const fenv_t __fe_dfl_env = {
  36         __INITIAL_NPXCW__,
  37         0x0000,
  38         0x0000,
  39         0x1f80,
  40         0xffffffff,
  41         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  42           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
  43 };
  44
  45 extern inline int feclearexcept(int __excepts);
  46 extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
  47
  48 int
  49 fesetexceptflag(const fexcept_t *flagp, int excepts)
  50 {
  51         fenv_t env;
  52         uint32_t mxcsr;
  53
  54         __fnstenv(&env);
  55         env.__status &= ~excepts;
  56         env.__status |= *flagp & excepts;
  57         __fldenv(env);
  58
  59         if (__HAS_SSE()) {
  60                 __stmxcsr(&mxcsr);
  61                 mxcsr &= ~excepts;
  62                 mxcsr |= *flagp & excepts;
  63                 __ldmxcsr(mxcsr);
  64         }
  65
  66         return (0);
  67 }
  68
  69 int
  70 feraiseexcept(int excepts)
  71 {
  72         fexcept_t ex = excepts;
  73
  74         fesetexceptflag(&ex, excepts);
  75         __fwait();
  76         return (0);
  77 }
  78
  79 extern inline int fetestexcept(int __excepts);
  80 extern inline int fegetround(void);
  81 extern inline int fesetround(int __round);
  82
  83 int
  84 fegetenv(fenv_t *envp)
  85 {
  86         uint32_t mxcsr;
  87
  88         __fnstenv(envp);
  89         /*
  90          * fnstenv masks all exceptions, so we need to restore
  91          * the old control word to avoid this side effect.
  92          */
  93         __fldcw(envp->__control);
  94         if (__HAS_SSE()) {
  95                 __stmxcsr(&mxcsr);
  96                 __set_mxcsr(*envp, mxcsr);
  97         }
  98         return (0);
  99 }
 100
 101 int
 102 feholdexcept(fenv_t *envp)
 103 {
 104         uint32_t mxcsr;
 105
 106         __fnstenv(envp);
 107         __fnclex();
 108         if (__HAS_SSE()) {
 109                 __stmxcsr(&mxcsr);
 110                 __set_mxcsr(*envp, mxcsr);
 111                 mxcsr &= ~FE_ALL_EXCEPT;
 112                 mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
 113                 __ldmxcsr(mxcsr);
 114         }
 115         return (0);
 116 }
 117
 118 extern inline int fesetenv(const fenv_t *__envp);
 119
 120 int
 121 feupdateenv(const fenv_t *envp)
 122 {
 123         uint32_t mxcsr;
 124         uint16_t status;
 125
 126         __fnstsw(&status);
 127         if (__HAS_SSE())
 128                 __stmxcsr(&mxcsr);
 129         else
 130                 mxcsr = 0;
 131         fesetenv(envp);
 132         feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
 133         return (0);
 134 }
 135
 136 int
 137 __feenableexcept(int mask)
 138 {
 139         uint32_t mxcsr, omask;
 140         uint16_t control;
 141
 142         mask &= FE_ALL_EXCEPT;
 143         __fnstcw(&control);
 144         if (__HAS_SSE())
 145                 __stmxcsr(&mxcsr);
 146         else
 147                 mxcsr = 0;
 148         omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
 149         control &= ~mask;
 150         __fldcw(control);
 151         if (__HAS_SSE()) {
 152                 mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
 153                 __ldmxcsr(mxcsr);
 154         }
 155         return (omask);
 156 }
 157
 158 int
 159 __fedisableexcept(int mask)
 160 {
 161         uint32_t mxcsr, omask;
 162         uint16_t control;
 163
 164         mask &= FE_ALL_EXCEPT;
 165         __fnstcw(&control);
 166         if (__HAS_SSE())
 167                 __stmxcsr(&mxcsr);
 168         else
 169                 mxcsr = 0;
 170         omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
 171         control |= mask;
 172         __fldcw(control);
 173         if (__HAS_SSE()) {
 174                 mxcsr |= mask << _SSE_EMASK_SHIFT;
 175                 __ldmxcsr(mxcsr);
 176         }
 177         return (omask);
 178 }
 179
 180 AROS_MAKE_ASM_SYM(typeof(feenableexcept), feenableexcept, AROS_CSYM_FROM_ASM_NAME(feenableexcept), AROS_CSYM_FROM_ASM_NAME(__feenableexcept));
 181 AROS_EXPORT_ASM_SYM(AROS_CSYM_FROM_ASM_NAME(feenableexcept));
 182
 183 AROS_MAKE_ASM_SYM(typeof(fedisableexcept), fedisableexcept, AROS_CSYM_FROM_ASM_NAME(fedisableexcept), AROS_CSYM_FROM_ASM_NAME(__fedisableexcept));
 184 AROS_EXPORT_ASM_SYM(AROS_CSYM_FROM_ASM_NAME(fedisableexcept));