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      1 /*-
      2  * Copyright (c) 2004-2005 David Schultz <das (at) 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/arm/fenv.h,v 1.5 2005/03/16 19:03:45 das Exp $
     27  */
     28 
     29 /*
     30  * Rewritten for Android.
     31  *
     32  * The ARM FPSCR is described here:
     33  * http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0344b/Chdfafia.html
     34  */
     35 
     36 #ifndef _FENV_H_
     37 #define _FENV_H_
     38 
     39 #include <sys/types.h>
     40 
     41 __BEGIN_DECLS
     42 
     43 typedef __uint32_t fenv_t;
     44 typedef __uint32_t fexcept_t;
     45 
     46 /* Exception flags. */
     47 #define FE_INVALID    0x01
     48 #define FE_DIVBYZERO  0x02
     49 #define FE_OVERFLOW   0x04
     50 #define FE_UNDERFLOW  0x08
     51 #define FE_INEXACT    0x10
     52 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
     53 #define _FPSCR_ENABLE_SHIFT 8
     54 #define _FPSCR_ENABLE_MASK (FE_ALL_EXCEPT << _FPSCR_ENABLE_SHIFT)
     55 
     56 /* Rounding modes. */
     57 #define FE_TONEAREST  0x0
     58 #define FE_UPWARD     0x1
     59 #define FE_DOWNWARD   0x2
     60 #define FE_TOWARDZERO 0x3
     61 #define _FPSCR_RMODE_SHIFT 22
     62 
     63 /* Default floating-point environment. */
     64 extern const fenv_t __fe_dfl_env;
     65 #define FE_DFL_ENV (&__fe_dfl_env)
     66 
     67 static __inline int fegetenv(fenv_t* __envp) {
     68   fenv_t _fpscr;
     69   __asm__ __volatile__("vmrs %0,fpscr" : "=r" (_fpscr));
     70   *__envp = _fpscr;
     71   return 0;
     72 }
     73 
     74 static __inline int fesetenv(const fenv_t* __envp) {
     75   fenv_t _fpscr = *__envp;
     76   __asm__ __volatile__("vmsr fpscr,%0" : :"ri" (_fpscr));
     77   return 0;
     78 }
     79 
     80 static __inline int feclearexcept(int __excepts) {
     81   fexcept_t __fpscr;
     82   fegetenv(&__fpscr);
     83   __fpscr &= ~__excepts;
     84   fesetenv(&__fpscr);
     85   return 0;
     86 }
     87 
     88 static __inline int fegetexceptflag(fexcept_t* __flagp, int __excepts) {
     89   fexcept_t __fpscr;
     90   fegetenv(&__fpscr);
     91   *__flagp = __fpscr & __excepts;
     92   return 0;
     93 }
     94 
     95 static __inline int fesetexceptflag(const fexcept_t* __flagp, int __excepts) {
     96   fexcept_t __fpscr;
     97   fegetenv(&__fpscr);
     98   __fpscr &= ~__excepts;
     99   __fpscr |= *__flagp & __excepts;
    100   fesetenv(&__fpscr);
    101   return 0;
    102 }
    103 
    104 static __inline int feraiseexcept(int __excepts) {
    105   fexcept_t __ex = __excepts;
    106   fesetexceptflag(&__ex, __excepts);
    107   return 0;
    108 }
    109 
    110 static __inline int fetestexcept(int __excepts) {
    111   fexcept_t __fpscr;
    112   fegetenv(&__fpscr);
    113   return (__fpscr & __excepts);
    114 }
    115 
    116 static __inline int fegetround(void) {
    117   fenv_t _fpscr;
    118   fegetenv(&_fpscr);
    119   return ((_fpscr >> _FPSCR_RMODE_SHIFT) & 0x3);
    120 }
    121 
    122 static __inline int fesetround(int __round) {
    123   fenv_t _fpscr;
    124   fegetenv(&_fpscr);
    125   _fpscr &= ~(0x3 << _FPSCR_RMODE_SHIFT);
    126   _fpscr |= (__round << _FPSCR_RMODE_SHIFT);
    127   fesetenv(&_fpscr);
    128   return 0;
    129 }
    130 
    131 static __inline int feholdexcept(fenv_t* __envp) {
    132   fenv_t __env;
    133   fegetenv(&__env);
    134   *__envp = __env;
    135   __env &= ~(FE_ALL_EXCEPT | _FPSCR_ENABLE_MASK);
    136   fesetenv(&__env);
    137   return 0;
    138 }
    139 
    140 static __inline int feupdateenv(const fenv_t* __envp) {
    141   fexcept_t __fpscr;
    142   fegetenv(&__fpscr);
    143   fesetenv(__envp);
    144   feraiseexcept(__fpscr & FE_ALL_EXCEPT);
    145   return 0;
    146 }
    147 
    148 #if __BSD_VISIBLE
    149 
    150 static __inline int feenableexcept(int __mask) {
    151   fenv_t __old_fpscr, __new_fpscr;
    152   fegetenv(&__old_fpscr);
    153   __new_fpscr = __old_fpscr | (__mask & FE_ALL_EXCEPT) << _FPSCR_ENABLE_SHIFT;
    154   fesetenv(&__new_fpscr);
    155   return ((__old_fpscr >> _FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
    156 }
    157 
    158 static __inline int fedisableexcept(int __mask) {
    159   fenv_t __old_fpscr, __new_fpscr;
    160   fegetenv(&__old_fpscr);
    161   __new_fpscr = __old_fpscr & ~((__mask & FE_ALL_EXCEPT) << _FPSCR_ENABLE_SHIFT);
    162   fesetenv(&__new_fpscr);
    163   return ((__old_fpscr >> _FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
    164 }
    165 
    166 static __inline int fegetexcept(void) {
    167   fenv_t __fpscr;
    168   fegetenv(&__fpscr);
    169   return ((__fpscr & _FPSCR_ENABLE_MASK) >> _FPSCR_ENABLE_SHIFT);
    170 }
    171 
    172 #endif /* __BSD_VISIBLE */
    173 
    174 __END_DECLS
    175 
    176 #endif /* !_FENV_H_ */
    177