arch/x86_64-all/include/aros/fenv.h

   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.h,v 1.6 2007/01/06 21:46:23 das Exp $
  27  */
  28
  29 #ifndef _FENV_H_
  30 #define _FENV_H_
  31
  32 #include <aros/system.h>
  33 #include <aros/types/int_t.h>
  34
  35 /*
  36  * To preserve binary compatibility with FreeBSD 5.3, we pack the
  37  * mxcsr into some reserved fields, rather than changing sizeof(fenv_t).
  38  */
  39 typedef struct {
  40         struct {
  41                 uint32_t        __control;
  42                 uint32_t        __status;
  43                 uint32_t        __tag;
  44                 char            __other[16];
  45         } __x87;
  46         uint32_t                __mxcsr;
  47 } fenv_t;
  48
  49 typedef uint16_t        fexcept_t;
  50
  51 /* Exception flags */
  52 #define FE_INVALID      0x01
  53 #define FE_DENORMAL     0x02
  54 #define FE_DIVBYZERO    0x04
  55 #define FE_OVERFLOW     0x08
  56 #define FE_UNDERFLOW    0x10
  57 #define FE_INEXACT      0x20
  58 #define FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
  59                          FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
  60
  61 /* Rounding modes */
  62 #define FE_TONEAREST    0x0000
  63 #define FE_DOWNWARD     0x0400
  64 #define FE_UPWARD       0x0800
  65 #define FE_TOWARDZERO   0x0c00
  66 #define _ROUND_MASK     (FE_TONEAREST | FE_DOWNWARD | \
  67                          FE_UPWARD | FE_TOWARDZERO)
  68
  69 /*
  70  * As compared to the x87 control word, the SSE unit's control word
  71  * has the rounding control bits offset by 3 and the exception mask
  72  * bits offset by 7.
  73  */
  74 #define _SSE_ROUND_SHIFT        3
  75 #define _SSE_EMASK_SHIFT        7
  76
  77 __BEGIN_DECLS
  78
  79 /* Default floating-point environment */
  80 extern const fenv_t     __fe_dfl_env;
  81 #define FE_DFL_ENV      (&__fe_dfl_env)
  82
  83 #define __fldcw(__cw)           __asm __volatile("fldcw %0" : : "m" (__cw))
  84 #define __fldenv(__env)         __asm __volatile("fldenv %0" : : "m" (__env))
  85 #define __fldenvx(__env)        __asm __volatile("fldenv %0" : : "m" (__env)  \
  86                                 : "st", "st(1)", "st(2)", "st(3)", "st(4)",   \
  87                                 "st(5)", "st(6)", "st(7)")
  88 #define __fnclex()              __asm __volatile("fnclex")
  89 #define __fnstenv(__env)        __asm __volatile("fnstenv %0" : "=m" (*(__env)))
  90 #define __fnstcw(__cw)          __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
  91 #define __fnstsw(__sw)          __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
  92 #define __fwait()               __asm __volatile("fwait")
  93 #define __ldmxcsr(__csr)        __asm __volatile("ldmxcsr %0" : : "m" (__csr))
  94 #define __stmxcsr(__csr)        __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
  95
  96 #ifndef STDC_NOINLINE
  97 static __inline int
  98 feclearexcept(int __excepts)
  99 {
 100         fenv_t __env;
 101
 102         if (__excepts == FE_ALL_EXCEPT) {
 103                 __fnclex();
 104         } else {
 105                 __fnstenv(&__env.__x87);
 106                 __env.__x87.__status &= ~__excepts;
 107                 __fldenv(__env.__x87);
 108         }
 109         __stmxcsr(&__env.__mxcsr);
 110         __env.__mxcsr &= ~__excepts;
 111         __ldmxcsr(__env.__mxcsr);
 112         return (0);
 113 }
 114
 115 static __inline int
 116 fegetexceptflag(fexcept_t *__flagp, int __excepts)
 117 {
 118         uint32_t __mxcsr;
 119         uint16_t __status;
 120
 121         __stmxcsr(&__mxcsr);
 122         __fnstsw(&__status);
 123         *__flagp = (__mxcsr | __status) & __excepts;
 124         return (0);
 125 }
 126 #endif /* !STDC_NOINLINE */
 127
 128 int fegetenv(fenv_t *__envp);
 129 int feholdexcept(fenv_t *__envp);
 130 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
 131 int feraiseexcept(int __excepts);
 132
 133 #ifndef STDC_NOINLINE
 134 static __inline int
 135 fetestexcept(int __excepts)
 136 {
 137         uint32_t __mxcsr;
 138         uint16_t __status;
 139
 140         __stmxcsr(&__mxcsr);
 141         __fnstsw(&__status);
 142         return ((__status | __mxcsr) & __excepts);
 143 }
 144
 145 static __inline int
 146 fegetround(void)
 147 {
 148         uint16_t __control;
 149
 150         /*
 151          * We assume that the x87 and the SSE unit agree on the
 152          * rounding mode.  Reading the control word on the x87 turns
 153          * out to be about 5 times faster than reading it on the SSE
 154          * unit on an Opteron 244.
 155          */
 156         __fnstcw(&__control);
 157         return (__control & _ROUND_MASK);
 158 }
 159
 160 static __inline int
 161 fesetround(int __round)
 162 {
 163         uint32_t __mxcsr;
 164         uint16_t __control;
 165
 166         if (__round & ~_ROUND_MASK)
 167                 return (-1);
 168
 169         __fnstcw(&__control);
 170         __control &= ~_ROUND_MASK;
 171         __control |= __round;
 172         __fldcw(__control);
 173
 174         __stmxcsr(&__mxcsr);
 175         __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
 176         __mxcsr |= __round << _SSE_ROUND_SHIFT;
 177         __ldmxcsr(__mxcsr);
 178
 179         return (0);
 180 }
 181 #endif /* !STDC_NOINLINE */
 182
 183 #ifndef STDC_NOINLINE
 184 static __inline int
 185 fesetenv(const fenv_t *__envp)
 186 {
 187
 188         /*
 189          * XXX Using fldenvx() instead of fldenv() tells the compiler that this
 190          * instruction clobbers the i387 register stack.  This happens because
 191          * we restore the tag word from the saved environment.  Normally, this
 192          * would happen anyway and we wouldn't care, because the ABI allows
 193          * function calls to clobber the i387 regs.  However, fesetenv() is
 194          * inlined, so we need to be more careful.
 195          */
 196         __fldenvx(__envp->__x87);
 197         __ldmxcsr(__envp->__mxcsr);
 198         return (0);
 199 }
 200 #endif /* !STDC_NOINLINE */
 201
 202 int feupdateenv(const fenv_t *__envp);
 203
 204 #if __BSD_VISIBLE
 205
 206 int feenableexcept(int __mask);
 207 int fedisableexcept(int __mask);
 208
 209 #ifndef STDC_NOINLINE
 210 static __inline int
 211 fegetexcept(void)
 212 {
 213         uint16_t __control;
 214
 215         /*
 216          * We assume that the masks for the x87 and the SSE unit are
 217          * the same.
 218          */
 219         __fnstcw(&__control);
 220         return (~__control & FE_ALL_EXCEPT);
 221 }
 222 #endif /* !STDC_NOINLINE */
 223
 224 #endif /* __BSD_VISIBLE */
 225
 226 __END_DECLS
 227
 228 #endif  /* !_FENV_H_ */