arch/x86_64-all/include/aros/x86_64/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/amd64/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 <sys/cdefs.h>
  33 #include <sys/_types.h>
  34
  35 typedef struct {
  36         struct {
  37                 __uint32_t      __control;
  38                 __uint32_t      __status;
  39                 __uint32_t      __tag;
  40                 char            __other[16];
  41         } __x87;
  42         __uint32_t              __mxcsr;
  43 } fenv_t;
  44
  45 typedef __uint16_t      fexcept_t;
  46
  47 /* Exception flags */
  48 #define FE_INVALID      0x01
  49 #define FE_DENORMAL     0x02
  50 #define FE_DIVBYZERO    0x04
  51 #define FE_OVERFLOW     0x08
  52 #define FE_UNDERFLOW    0x10
  53 #define FE_INEXACT      0x20
  54 #define FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
  55                          FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
  56
  57 /* Rounding modes */
  58 #define FE_TONEAREST    0x0000
  59 #define FE_DOWNWARD     0x0400
  60 #define FE_UPWARD       0x0800
  61 #define FE_TOWARDZERO   0x0c00
  62 #define _ROUND_MASK     (FE_TONEAREST | FE_DOWNWARD | \
  63                          FE_UPWARD | FE_TOWARDZERO)
  64
  65 /*
  66  * As compared to the x87 control word, the SSE unit's control word
  67  * has the rounding control bits offset by 3 and the exception mask
  68  * bits offset by 7.
  69  */
  70 #define _SSE_ROUND_SHIFT        3
  71 #define _SSE_EMASK_SHIFT        7
  72
  73 __BEGIN_DECLS
  74
  75 /* Default floating-point environment */
  76 extern const fenv_t     __fe_dfl_env;
  77 #define FE_DFL_ENV      (&__fe_dfl_env)
  78
  79 #define __fldcw(__cw)           __asm __volatile("fldcw %0" : : "m" (__cw))
  80 #define __fldenv(__env)         __asm __volatile("fldenv %0" : : "m" (__env))
  81 #define __fldenvx(__env)        __asm __volatile("fldenv %0" : : "m" (__env)  \
  82                                 : "st", "st(1)", "st(2)", "st(3)", "st(4)",   \
  83                                 "st(5)", "st(6)", "st(7)")
  84 #define __fnclex()              __asm __volatile("fnclex")
  85 #define __fnstenv(__env)        __asm __volatile("fnstenv %0" : "=m" (*(__env)))
  86 #define __fnstcw(__cw)          __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
  87 #define __fnstsw(__sw)          __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
  88 #define __fwait()               __asm __volatile("fwait")
  89 #define __ldmxcsr(__csr)        __asm __volatile("ldmxcsr %0" : : "m" (__csr))
  90 #define __stmxcsr(__csr)        __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
  91
  92 static __inline int
  93 feclearexcept(int __excepts)
  94 {
  95         fenv_t __env;
  96
  97         if (__excepts == FE_ALL_EXCEPT) {
  98                 __fnclex();
  99         } else {
 100                 __fnstenv(&__env.__x87);
 101                 __env.__x87.__status &= ~__excepts;
 102                 __fldenv(__env.__x87);
 103         }
 104         __stmxcsr(&__env.__mxcsr);
 105         __env.__mxcsr &= ~__excepts;
 106         __ldmxcsr(__env.__mxcsr);
 107         return (0);
 108 }
 109
 110 static __inline int
 111 fegetexceptflag(fexcept_t *__flagp, int __excepts)
 112 {
 113         int __mxcsr, __status;
 114
 115         __stmxcsr(&__mxcsr);
 116         __fnstsw(&__status);
 117         *__flagp = (__mxcsr | __status) & __excepts;
 118         return (0);
 119 }
 120
 121 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
 122 int feraiseexcept(int __excepts);
 123
 124 static __inline int
 125 fetestexcept(int __excepts)
 126 {
 127         int __mxcsr, __status;
 128
 129         __stmxcsr(&__mxcsr);
 130         __fnstsw(&__status);
 131         return ((__status | __mxcsr) & __excepts);
 132 }
 133
 134 static __inline int
 135 fegetround(void)
 136 {
 137         int __control;
 138
 139         /*
 140          * We assume that the x87 and the SSE unit agree on the
 141          * rounding mode.  Reading the control word on the x87 turns
 142          * out to be about 5 times faster than reading it on the SSE
 143          * unit on an Opteron 244.
 144          */
 145         __fnstcw(&__control);
 146         return (__control & _ROUND_MASK);
 147 }
 148
 149 static __inline int
 150 fesetround(int __round)
 151 {
 152         int __mxcsr, __control;
 153
 154         if (__round & ~_ROUND_MASK)
 155                 return (-1);
 156
 157         __fnstcw(&__control);
 158         __control &= ~_ROUND_MASK;
 159         __control |= __round;
 160         __fldcw(__control);
 161
 162         __stmxcsr(&__mxcsr);
 163         __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
 164         __mxcsr |= __round << _SSE_ROUND_SHIFT;
 165         __ldmxcsr(__mxcsr);
 166
 167         return (0);
 168 }
 169
 170 int fegetenv(fenv_t *__envp);
 171 int feholdexcept(fenv_t *__envp);
 172
 173 static __inline int
 174 fesetenv(const fenv_t *__envp)
 175 {
 176
 177         /*
 178          * XXX Using fldenvx() instead of fldenv() tells the compiler that this
 179          * instruction clobbers the i387 register stack.  This happens because
 180          * we restore the tag word from the saved environment.  Normally, this
 181          * would happen anyway and we wouldn't care, because the ABI allows
 182          * function calls to clobber the i387 regs.  However, fesetenv() is
 183          * inlined, so we need to be more careful.
 184          */
 185         __fldenvx(__envp->__x87);
 186         __ldmxcsr(__envp->__mxcsr);
 187         return (0);
 188 }
 189
 190 int feupdateenv(const fenv_t *__envp);
 191
 192 #if __BSD_VISIBLE
 193
 194 int feenableexcept(int __mask);
 195 int fedisableexcept(int __mask);
 196
 197 static __inline int
 198 fegetexcept(void)
 199 {
 200         int __control;
 201
 202         /*
 203          * We assume that the masks for the x87 and the SSE unit are
 204          * the same.
 205          */
 206         __fnstcw(&__control);
 207         return (~__control & FE_ALL_EXCEPT);
 208 }
 209
 210 #endif /* __BSD_VISIBLE */
 211
 212 __END_DECLS
 213
 214 #endif  /* !_FENV_H_ */