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ocintrin.h

/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE.   *
 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
 *                                                                  *
 * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2007                *
 * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
 *                                                                  *
 ********************************************************************

  function:
    last mod: $Id: ocintrin.h 15400 2008-10-15 12:10:58Z tterribe $

 ********************************************************************/

/*Some common macros for potential platform-specific optimization.*/
#include <math.h>
#if !defined(_ocintrin_H)
# define _ocintrin_H (1)

/*Some specific platforms may have optimized intrinsic or inline assembly
   versions of these functions which can substantially improve performance.
  We define macros for them to allow easy incorporation of these non-ANSI
   features.*/

/*Branchless, but not correct for differences larger than INT_MAX.
static int oc_mini(int _a,int _b){
  int ambsign;
  ambsign=_a-_b>>sizeof(int)*8-1;
  return (_a&~ambsign)+(_b&ambsign);
}*/


#define OC_MAXI(_a,_b)      ((_a)<(_b)?(_b):(_a))
#define OC_MINI(_a,_b)      ((_a)>(_b)?(_b):(_a))
/*Clamps an integer into the given range.
  If _a>_c, then the lower bound _a is respected over the upper bound _c (this
   behavior is required to meet our documented API behavior).
  _a: The lower bound.
  _b: The value to clamp.
  _c: The upper boud.*/
#define OC_CLAMPI(_a,_b,_c) (OC_MAXI(_a,OC_MINI(_b,_c)))
#define OC_CLAMP255(_x)     ((unsigned char)((((_x)<0)-1)&((_x)|-((_x)>255))))
/*Divides an integer by a power of two, truncating towards 0.
  _dividend: The integer to divide.
  _shift:    The non-negative power of two to divide by.
  _rmask:    (1<<_shift)-1*/
#define OC_DIV_POW2(_dividend,_shift,_rmask)\
  ((_dividend)+(((_dividend)>>sizeof(_dividend)*8-1)&(_rmask))>>(_shift))
/*Divides _x by 65536, truncating towards 0.*/
#define OC_DIV2_16(_x) OC_DIV_POW2(_x,16,0xFFFF)
/*Divides _x by 2, truncating towards 0.*/
#define OC_DIV2(_x) OC_DIV_POW2(_x,1,0x1)
/*Divides _x by 8, truncating towards 0.*/
#define OC_DIV8(_x) OC_DIV_POW2(_x,3,0x7)
/*Divides _x by 16, truncating towards 0.*/
#define OC_DIV16(_x) OC_DIV_POW2(_x,4,0xF)
/*Right shifts _dividend by _shift, adding _rval, and subtracting one for
   negative dividends first..
  When _rval is (1<<_shift-1), this is equivalent to division with rounding
   ties towards positive infinity.*/
#define OC_DIV_ROUND_POW2(_dividend,_shift,_rval)\
  ((_dividend)+((_dividend)>>sizeof(_dividend)*8-1)+(_rval)>>(_shift))
/*Swaps two integers _a and _b if _a>_b.*/
#define OC_SORT2I(_a,_b)\
  if((_a)>(_b)){\
    int t__;\
    t__=(_a);\
    (_a)=(_b);\
    (_b)=t__;\
  }



/*All of these macros should expect floats as arguments.*/
#define OC_MAXF(_a,_b)      ((_a)<(_b)?(_b):(_a))
#define OC_MINF(_a,_b)      ((_a)>(_b)?(_b):(_a))
#define OC_CLAMPF(_a,_b,_c) (OC_MINF(_a,OC_MAXF(_b,_c)))
#define OC_FABSF(_f)        ((float)fabs(_f))
#define OC_SQRTF(_f)        ((float)sqrt(_f))
#define OC_POWF(_b,_e)      ((float)pow(_b,_e))
#define OC_LOGF(_f)         ((float)log(_f))
#define OC_IFLOORF(_f)      ((int)floor(_f))
#define OC_ICEILF(_f)       ((int)ceil(_f))

#endif

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