arch/i386-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         uint16_t        __control;
  41         uint16_t      __mxcsr_hi;
  42         uint16_t        __status;
  43         uint16_t      __mxcsr_lo;
  44         uint32_t        __tag;
  45         char            __other[16];
  46 } fenv_t;
  47
  48 #define __get_mxcsr(env)        (((env).__mxcsr_hi << 16) |     \
  49                                  ((env).__mxcsr_lo))
  50 #define __set_mxcsr(env, x)     do {                            \
  51         (env).__mxcsr_hi = (uint32_t)(x) >> 16;                 \
  52         (env).__mxcsr_lo = (uint16_t)(x);                       \
  53 } while (0)
  54
  55 typedef uint16_t        fexcept_t;
  56
  57 /* Exception flags */
  58 #define FE_INVALID      0x01
  59 #define FE_DENORMAL     0x02
  60 #define FE_DIVBYZERO    0x04
  61 #define FE_OVERFLOW     0x08
  62 #define FE_UNDERFLOW    0x10
  63 #define FE_INEXACT      0x20
  64 #define FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
  65                          FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
  66
  67 /* Rounding modes */
  68 #define FE_TONEAREST    0x0000
  69 #define FE_DOWNWARD     0x0400
  70 #define FE_UPWARD       0x0800
  71 #define FE_TOWARDZERO   0x0c00
  72 #define _ROUND_MASK     (FE_TONEAREST | FE_DOWNWARD | \
  73                          FE_UPWARD | FE_TOWARDZERO)
  74
  75 /*
  76  * As compared to the x87 control word, the SSE unit's control word
  77  * has the rounding control bits offset by 3 and the exception mask
  78  * bits offset by 7.
  79  */
  80 #define _SSE_ROUND_SHIFT        3
  81 #define _SSE_EMASK_SHIFT        7
  82
  83 __BEGIN_DECLS
  84
  85 /* After testing for SSE support once, we cache the result in __has_sse. */
  86 enum __sse_support { __SSE_YES, __SSE_NO, __SSE_UNK };
  87 extern enum __sse_support __has_sse;
  88 int __test_sse(void);
  89 #ifdef __SSE__
  90 #define __HAS_SSE()     1
  91 #else
  92 #define __HAS_SSE()     (__has_sse == __SSE_YES ||                      \
  93                          (__has_sse == __SSE_UNK && __test_sse()))
  94 #endif
  95
  96 /* Default floating-point environment */
  97 extern const fenv_t     __fe_dfl_env;
  98 #define FE_DFL_ENV      (&__fe_dfl_env)
  99
 100 #define __fldcw(__cw)           __asm __volatile("fldcw %0" : : "m" (__cw))
 101 #define __fldenv(__env)         __asm __volatile("fldenv %0" : : "m" (__env))
 102 #define __fldenvx(__env)        __asm __volatile("fldenv %0" : : "m" (__env)  \
 103                                 : "st", "st(1)", "st(2)", "st(3)", "st(4)",   \
 104                                 "st(5)", "st(6)", "st(7)")
 105 #define __fnclex()              __asm __volatile("fnclex")
 106 #define __fnstenv(__env)        __asm __volatile("fnstenv %0" : "=m" (*(__env)))
 107 #define __fnstcw(__cw)          __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
 108 #define __fnstsw(__sw)          __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
 109 #define __fwait()               __asm __volatile("fwait")
 110 #define __ldmxcsr(__csr)        __asm __volatile("ldmxcsr %0" : : "m" (__csr))
 111 #define __stmxcsr(__csr)        __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
 112
 113 #ifndef STDC_NOINLINE
 114 static __inline int
 115 feclearexcept(int __excepts)
 116 {
 117         fenv_t __env;
 118         int __mxcsr;
 119
 120         if (__excepts == FE_ALL_EXCEPT) {
 121                 __fnclex();
 122         } else {
 123                 __fnstenv(&__env);
 124                 __env.__status &= ~__excepts;
 125                 __fldenv(__env);
 126         }
 127         if (__HAS_SSE()) {
 128                 __stmxcsr(&__mxcsr);
 129                 __mxcsr &= ~__excepts;
 130                 __ldmxcsr(__mxcsr);
 131         }
 132         return (0);
 133 }
 134
 135 static __inline int
 136 fegetexceptflag(fexcept_t *__flagp, int __excepts)
 137 {
 138         int __mxcsr;
 139         short __status;
 140
 141         __fnstsw(&__status);
 142         if (__HAS_SSE())
 143                 __stmxcsr(&__mxcsr);
 144         else
 145                 __mxcsr = 0;
 146         *__flagp = (__mxcsr | __status) & __excepts;
 147         return (0);
 148 }
 149 #endif /* !STDC_NOINLINE */
 150
 151 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
 152 int feraiseexcept(int __excepts);
 153
 154 #ifndef STDC_NOINLINE
 155 static __inline int
 156 fetestexcept(int __excepts)
 157 {
 158         int __mxcsr;
 159         short __status;
 160
 161         __fnstsw(&__status);
 162         if (__HAS_SSE())
 163                 __stmxcsr(&__mxcsr);
 164         else
 165                 __mxcsr = 0;
 166         return ((__status | __mxcsr) & __excepts);
 167 }
 168
 169 static __inline int
 170 fegetround(void)
 171 {
 172         int __control;
 173
 174         /*
 175          * We assume that the x87 and the SSE unit agree on the
 176          * rounding mode.  Reading the control word on the x87 turns
 177          * out to be about 5 times faster than reading it on the SSE
 178          * unit on an Opteron 244.
 179          */
 180         __fnstcw(&__control);
 181         return (__control & _ROUND_MASK);
 182 }
 183
 184 static __inline int
 185 fesetround(int __round)
 186 {
 187         int __mxcsr, __control;
 188
 189         if (__round & ~_ROUND_MASK)
 190                 return (-1);
 191
 192         __fnstcw(&__control);
 193         __control &= ~_ROUND_MASK;
 194         __control |= __round;
 195         __fldcw(__control);
 196
 197         if (__HAS_SSE()) {
 198                 __stmxcsr(&__mxcsr);
 199                 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
 200                 __mxcsr |= __round << _SSE_ROUND_SHIFT;
 201                 __ldmxcsr(__mxcsr);
 202         }
 203
 204         return (0);
 205 }
 206 #endif /* !STDC_NOINLINE */
 207
 208 int fegetenv(fenv_t *__envp);
 209 int feholdexcept(fenv_t *__envp);
 210
 211 #ifndef STDC_NOINLINE
 212 static __inline int
 213 fesetenv(const fenv_t *__envp)
 214 {
 215         fenv_t __env = *__envp;
 216         int __mxcsr;
 217
 218         __mxcsr = __get_mxcsr(__env);
 219         __set_mxcsr(__env, 0xffffffff);
 220         /*
 221          * XXX Using fldenvx() instead of fldenv() tells the compiler that this
 222          * instruction clobbers the i387 register stack.  This happens because
 223          * we restore the tag word from the saved environment.  Normally, this
 224          * would happen anyway and we wouldn't care, because the ABI allows
 225          * function calls to clobber the i387 regs.  However, fesetenv() is
 226          * inlined, so we need to be more careful.
 227          */
 228         __fldenvx(__env);
 229         if (__HAS_SSE())
 230                 __ldmxcsr(__mxcsr);
 231         return (0);
 232 }
 233 #endif /* !STDC_NOINLINE */
 234
 235 int feupdateenv(const fenv_t *__envp);
 236
 237 #if __BSD_VISIBLE
 238
 239 int feenableexcept(int __mask);
 240 int fedisableexcept(int __mask);
 241
 242 #ifndef STDC_NOINLINE
 243 static __inline int
 244 fegetexcept(void)
 245 {
 246         int __control;
 247
 248         /*
 249          * We assume that the masks for the x87 and the SSE unit are
 250          * the same.
 251          */
 252         __fnstcw(&__control);
 253         return (~__control & FE_ALL_EXCEPT);
 254 }
 255 #endif /* !STDC_NOINLINE */
 256
 257 #endif /* __BSD_VISIBLE */
 258
 259 __END_DECLS
 260
 261 #endif  /* !_FENV_H_ */