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      1 #ifndef _OS_H
      2 #define _OS_H
      3 /********************************************************************
      4  *                                                                  *
      5  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
      6  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
      7  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
      8  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
      9  *                                                                  *
     10  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
     11  * by the Xiph.Org Foundation http://www.xiph.org/                  *
     12  *                                                                  *
     13  ********************************************************************
     14 
     15  function: #ifdef jail to whip a few platforms into the UNIX ideal.
     16  last mod: $Id: os.h 16227 2009-07-08 06:58:46Z xiphmont $
     17 
     18  ********************************************************************/
     19 
     20 #ifdef HAVE_CONFIG_H
     21 #include "config.h"
     22 #endif
     23 
     24 #include <math.h>
     25 #include <ogg/os_types.h>
     26 
     27 #include "misc.h"
     28 
     29 #ifndef _V_IFDEFJAIL_H_
     30 #  define _V_IFDEFJAIL_H_
     31 
     32 #  ifdef __GNUC__
     33 #    define STIN static __inline__
     34 #  elif _WIN32
     35 #    define STIN static __inline
     36 #  else
     37 #    define STIN static
     38 #  endif
     39 
     40 #ifdef DJGPP
     41 #  define rint(x)   (floor((x)+0.5f))
     42 #endif
     43 
     44 #ifndef M_PI
     45 #  define M_PI (3.1415926536f)
     46 #endif
     47 
     48 #if defined(_WIN32) && !defined(__SYMBIAN32__)
     49 #  include <malloc.h>
     50 #  define rint(x)   (floor((x)+0.5f))
     51 #  define NO_FLOAT_MATH_LIB
     52 #  define FAST_HYPOT(a, b) sqrt((a)*(a) + (b)*(b))
     53 #endif
     54 
     55 #if defined(__SYMBIAN32__) && defined(__WINS__)
     56 void *_alloca(size_t size);
     57 #  define alloca _alloca
     58 #endif
     59 
     60 #ifndef FAST_HYPOT
     61 #  define FAST_HYPOT hypot
     62 #endif
     63 
     64 #endif
     65 
     66 #ifdef HAVE_ALLOCA_H
     67 #  include <alloca.h>
     68 #endif
     69 
     70 #ifdef USE_MEMORY_H
     71 #  include <memory.h>
     72 #endif
     73 
     74 #ifndef min
     75 #  define min(x,y)  ((x)>(y)?(y):(x))
     76 #endif
     77 
     78 #ifndef max
     79 #  define max(x,y)  ((x)<(y)?(y):(x))
     80 #endif
     81 
     82 
     83 /* Special i386 GCC implementation */
     84 #if defined(__i386__) && defined(__GNUC__) && !defined(__BEOS__)
     85 #  define VORBIS_FPU_CONTROL
     86 /* both GCC and MSVC are kinda stupid about rounding/casting to int.
     87    Because of encapsulation constraints (GCC can't see inside the asm
     88    block and so we end up doing stupid things like a store/load that
     89    is collectively a noop), we do it this way */
     90 
     91 /* we must set up the fpu before this works!! */
     92 
     93 typedef ogg_int16_t vorbis_fpu_control;
     94 
     95 static inline void vorbis_fpu_setround(vorbis_fpu_control *fpu){
     96   ogg_int16_t ret;
     97   ogg_int16_t temp;
     98   __asm__ __volatile__("fnstcw %0\n\t"
     99           "movw %0,%%dx\n\t"
    100           "andw $62463,%%dx\n\t"
    101           "movw %%dx,%1\n\t"
    102           "fldcw %1\n\t":"=m"(ret):"m"(temp): "dx");
    103   *fpu=ret;
    104 }
    105 
    106 static inline void vorbis_fpu_restore(vorbis_fpu_control fpu){
    107   __asm__ __volatile__("fldcw %0":: "m"(fpu));
    108 }
    109 
    110 /* assumes the FPU is in round mode! */
    111 static inline int vorbis_ftoi(double f){  /* yes, double!  Otherwise,
    112                                              we get extra fst/fld to
    113                                              truncate precision */
    114   int i;
    115   __asm__("fistl %0": "=m"(i) : "t"(f));
    116   return(i);
    117 }
    118 #endif /* Special i386 GCC implementation */
    119 
    120 
    121 /* MSVC inline assembly. 32 bit only; inline ASM isn't implemented in the
    122  * 64 bit compiler */
    123 #if defined(_MSC_VER) && !defined(_WIN64) && !defined(_WIN32_WCE)
    124 #  define VORBIS_FPU_CONTROL
    125 
    126 typedef ogg_int16_t vorbis_fpu_control;
    127 
    128 static __inline int vorbis_ftoi(double f){
    129         int i;
    130         __asm{
    131                 fld f
    132                 fistp i
    133         }
    134         return i;
    135 }
    136 
    137 static __inline void vorbis_fpu_setround(vorbis_fpu_control *fpu){
    138 }
    139 
    140 static __inline void vorbis_fpu_restore(vorbis_fpu_control fpu){
    141 }
    142 
    143 #endif /* Special MSVC 32 bit implementation */
    144 
    145 
    146 /* Optimized code path for x86_64 builds. Uses SSE2 intrinsics. This can be
    147    done safely because all x86_64 CPUs supports SSE2. */
    148 #if (defined(_MSC_VER) && defined(_WIN64)) || (defined(__GNUC__) && defined (__x86_64__))
    149 #  define VORBIS_FPU_CONTROL
    150 
    151 typedef ogg_int16_t vorbis_fpu_control;
    152 
    153 #include <emmintrin.h>
    154 static __inline int vorbis_ftoi(double f){
    155         return _mm_cvtsd_si32(_mm_load_sd(&f));
    156 }
    157 
    158 static __inline void vorbis_fpu_setround(vorbis_fpu_control *fpu){
    159 }
    160 
    161 static __inline void vorbis_fpu_restore(vorbis_fpu_control fpu){
    162 }
    163 
    164 #endif /* Special MSVC x64 implementation */
    165 
    166 
    167 /* If no special implementation was found for the current compiler / platform,
    168    use the default implementation here: */
    169 #ifndef VORBIS_FPU_CONTROL
    170 
    171 typedef int vorbis_fpu_control;
    172 
    173 static int vorbis_ftoi(double f){
    174         /* Note: MSVC and GCC (at least on some systems) round towards zero, thus,
    175            the floor() call is required to ensure correct roudning of
    176            negative numbers */
    177         return (int)floor(f+.5);
    178 }
    179 
    180 /* We don't have special code for this compiler/arch, so do it the slow way */
    181 #  define vorbis_fpu_setround(vorbis_fpu_control) {}
    182 #  define vorbis_fpu_restore(vorbis_fpu_control) {}
    183 
    184 #endif /* default implementation */
    185 
    186 #endif /* _OS_H */
    187