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      1 /* Copyright (C) 2001 Erik de Castro Lopo <erikd AT mega-nerd DOT com> */
      2 /*
      3    Redistribution and use in source and binary forms, with or without
      4    modification, are permitted provided that the following conditions
      5    are met:
      6 
      7    - Redistributions of source code must retain the above copyright
      8    notice, this list of conditions and the following disclaimer.
      9 
     10    - 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
     15    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     16    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     17    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
     18    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     19    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     21    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     22    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     23    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     24    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25 */
     26 
     27 /* Version 1.1 */
     28 
     29 #ifndef FLOAT_CAST_H
     30 #define FLOAT_CAST_H
     31 
     32 
     33 #include "arch.h"
     34 
     35 /*============================================================================
     36 **      On Intel Pentium processors (especially PIII and probably P4), converting
     37 **      from float to int is very slow. To meet the C specs, the code produced by
     38 **      most C compilers targeting Pentium needs to change the FPU rounding mode
     39 **      before the float to int conversion is performed.
     40 **
     41 **      Changing the FPU rounding mode causes the FPU pipeline to be flushed. It
     42 **      is this flushing of the pipeline which is so slow.
     43 **
     44 **      Fortunately the ISO C99 specifications define the functions lrint, lrintf,
     45 **      llrint and llrintf which fix this problem as a side effect.
     46 **
     47 **      On Unix-like systems, the configure process should have detected the
     48 **      presence of these functions. If they weren't found we have to replace them
     49 **      here with a standard C cast.
     50 */
     51 
     52 /*
     53 **      The C99 prototypes for lrint and lrintf are as follows:
     54 **
     55 **              long int lrintf (float x) ;
     56 **              long int lrint  (double x) ;
     57 */
     58 
     59 /*      The presence of the required functions are detected during the configure
     60 **      process and the values HAVE_LRINT and HAVE_LRINTF are set accordingly in
     61 **      the config.h file.
     62 */
     63 
     64 #if (HAVE_LRINTF)
     65 
     66 /*      These defines enable functionality introduced with the 1999 ISO C
     67 **      standard. They must be defined before the inclusion of math.h to
     68 **      engage them. If optimisation is enabled, these functions will be
     69 **      inlined. With optimisation switched off, you have to link in the
     70 **      maths library using -lm.
     71 */
     72 
     73 #define _ISOC9X_SOURCE 1
     74 #define _ISOC99_SOURCE 1
     75 
     76 #define __USE_ISOC9X 1
     77 #define __USE_ISOC99 1
     78 
     79 #include <math.h>
     80 #define float2int(x) lrintf(x)
     81 
     82 #elif (defined(HAVE_LRINT))
     83 
     84 #define _ISOC9X_SOURCE 1
     85 #define _ISOC99_SOURCE 1
     86 
     87 #define __USE_ISOC9X 1
     88 #define __USE_ISOC99 1
     89 
     90 #include <math.h>
     91 #define float2int(x) lrint(x)
     92 
     93 #elif (defined(_MSC_VER) && _MSC_VER >= 1400) && (defined (WIN64) || defined (_WIN64))
     94         #include <xmmintrin.h>
     95 
     96         __inline long int float2int(float value)
     97         {
     98                 return _mm_cvtss_si32(_mm_load_ss(&value));
     99         }
    100 #elif (defined(_MSC_VER) && _MSC_VER >= 1400) && (defined (WIN32) || defined (_WIN32))
    101         #include <math.h>
    102 
    103         /*      Win32 doesn't seem to have these functions.
    104         **      Therefore implement inline versions of these functions here.
    105         */
    106 
    107         __inline long int
    108         float2int (float flt)
    109         {       int intgr;
    110 
    111                 _asm
    112                 {       fld flt
    113                         fistp intgr
    114                 } ;
    115 
    116                 return intgr ;
    117         }
    118 
    119 #else
    120 
    121 #if (defined(__GNUC__) && defined(__STDC__) && __STDC__ && __STDC_VERSION__ >= 199901L)
    122         /* supported by gcc in C99 mode, but not by all other compilers */
    123         #warning "Don't have the functions lrint() and lrintf ()."
    124         #warning "Replacing these functions with a standard C cast."
    125 #endif /* __STDC_VERSION__ >= 199901L */
    126         #include <math.h>
    127         #define float2int(flt) ((int)(floor(.5+flt)))
    128 #endif
    129 
    130 #ifndef DISABLE_FLOAT_API
    131 static inline opus_int16 FLOAT2INT16(float x)
    132 {
    133    x = x*CELT_SIG_SCALE;
    134    x = MAX32(x, -32768);
    135    x = MIN32(x, 32767);
    136    return (opus_int16)float2int(x);
    137 }
    138 #endif /* DISABLE_FLOAT_API */
    139 
    140 #endif /* FLOAT_CAST_H */
    141