The Tor Browser: media/libtremor/lib/misc.h@6474c204b198 (annotated)

media/libtremor/lib/misc.h@6474c204b198 (annotated)

media/libtremor/lib/misc.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /********************************************************************
  *                                                                  *
  * THIS FILE IS PART OF THE OggVorbis 'TREMOR' 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 OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
  function: miscellaneous math and prototypes
  ********************************************************************/
 #ifndef _V_RANDOM_H_
 #define _V_RANDOM_H_
 #include "ivorbiscodec.h"
 #include "os.h"
 #ifdef _LOW_ACCURACY_
 #  define X(n) (((((n)>>22)+1)>>1) - ((((n)>>22)+1)>>9))
 #  define LOOKUP_T const unsigned char
 #else
 #  define X(n) (n)
 #  define LOOKUP_T const ogg_int32_t
 #endif
 #include "asm_arm.h"
 #include <stdlib.h> /* for abs() */
 #ifndef _V_WIDE_MATH
 #define _V_WIDE_MATH
 #ifndef  _LOW_ACCURACY_
 /* 64 bit multiply */
 #if !(defined WIN32 && defined WINCE)
 #include <sys/types.h>
 #endif
 #if BYTE_ORDER==LITTLE_ENDIAN
 union magic {
   struct {
     ogg_int32_t lo;
     ogg_int32_t hi;
   } halves;
   ogg_int64_t whole;
 };
 #elif BYTE_ORDER==BIG_ENDIAN
 union magic {
   struct {
     ogg_int32_t hi;
     ogg_int32_t lo;
   } halves;
   ogg_int64_t whole;
 };
 #endif
 STIN ogg_int32_t MULT32(ogg_int32_t x, ogg_int32_t y) {
   union magic magic;
   magic.whole = (ogg_int64_t)x * y;
   return magic.halves.hi;
 }
 STIN ogg_int32_t MULT31(ogg_int32_t x, ogg_int32_t y) {
   return MULT32(x,y)<<1;
 }
 STIN ogg_int32_t MULT31_SHIFT15(ogg_int32_t x, ogg_int32_t y) {
   union magic magic;
   magic.whole  = (ogg_int64_t)x * y;
   return ((ogg_uint32_t)(magic.halves.lo)>>15) | ((magic.halves.hi)<<17);
 }
 #else
 /* 32 bit multiply, more portable but less accurate */
 /*
  * Note: Precision is biased towards the first argument therefore ordering
  * is important.  Shift values were chosen for the best sound quality after
  * many listening tests.
  */
 /*
  * For MULT32 and MULT31: The second argument is always a lookup table
  * value already preshifted from 31 to 8 bits.  We therefore take the
  * opportunity to save on text space and use unsigned char for those
  * tables in this case.
  */
 STIN ogg_int32_t MULT32(ogg_int32_t x, ogg_int32_t y) {
   return (x >> 9) * y;  /* y preshifted >>23 */
 }
 STIN ogg_int32_t MULT31(ogg_int32_t x, ogg_int32_t y) {
   return (x >> 8) * y;  /* y preshifted >>23 */
 }
 STIN ogg_int32_t MULT31_SHIFT15(ogg_int32_t x, ogg_int32_t y) {
   return (x >> 6) * y;  /* y preshifted >>9 */
 }
 #endif
 /*
  * This should be used as a memory barrier, forcing all cached values in
  * registers to wr writen back to memory.  Might or might not be beneficial
  * depending on the architecture and compiler.
  */
 #define MB()
 /*
  * The XPROD functions are meant to optimize the cross products found all
  * over the place in mdct.c by forcing memory operation ordering to avoid
  * unnecessary register reloads as soon as memory is being written to.
  * However this is only beneficial on CPUs with a sane number of general
  * purpose registers which exclude the Intel x86.  On Intel, better let the
  * compiler actually reload registers directly from original memory by using
  * macros.
  */
 #ifdef __i386__
 #define XPROD32(_a, _b, _t, _v, _x, _y)		\
   { *(_x)=MULT32(_a,_t)+MULT32(_b,_v);		\
     *(_y)=MULT32(_b,_t)-MULT32(_a,_v); }
 #define XPROD31(_a, _b, _t, _v, _x, _y)		\
   { *(_x)=MULT31(_a,_t)+MULT31(_b,_v);		\
     *(_y)=MULT31(_b,_t)-MULT31(_a,_v); }
 #define XNPROD31(_a, _b, _t, _v, _x, _y)	\
   { *(_x)=MULT31(_a,_t)-MULT31(_b,_v);		\
     *(_y)=MULT31(_b,_t)+MULT31(_a,_v); }
 #else
 STIN void XPROD32(ogg_int32_t  a, ogg_int32_t  b,
 			   ogg_int32_t  t, ogg_int32_t  v,
 			   ogg_int32_t *x, ogg_int32_t *y)
 {
   *x = MULT32(a, t) + MULT32(b, v);
   *y = MULT32(b, t) - MULT32(a, v);
 }
 STIN void XPROD31(ogg_int32_t  a, ogg_int32_t  b,
 			   ogg_int32_t  t, ogg_int32_t  v,
 			   ogg_int32_t *x, ogg_int32_t *y)
 {
   *x = MULT31(a, t) + MULT31(b, v);
   *y = MULT31(b, t) - MULT31(a, v);
 }
 STIN void XNPROD31(ogg_int32_t  a, ogg_int32_t  b,
 			    ogg_int32_t  t, ogg_int32_t  v,
 			    ogg_int32_t *x, ogg_int32_t *y)
 {
   *x = MULT31(a, t) - MULT31(b, v);
   *y = MULT31(b, t) + MULT31(a, v);
 }
 #endif
 #endif
 #ifndef _V_CLIP_MATH
 #define _V_CLIP_MATH
 STIN ogg_int32_t CLIP_TO_15(ogg_int32_t x) {
   int ret=x;
   ret-= ((x<=32767)-1)&(x-32767);
   ret-= ((x>=-32768)-1)&(x+32768);
   return(ret);
 }
 #endif
 STIN ogg_int32_t VFLOAT_MULT(ogg_int32_t a,ogg_int32_t ap,
 				      ogg_int32_t b,ogg_int32_t bp,
 				      ogg_int32_t *p){
   if(a && b){
 #ifndef _LOW_ACCURACY_
     *p=ap+bp+32;
     return MULT32(a,b);
 #else
     *p=ap+bp+31;
     return (a>>15)*(b>>16);
 #endif
   }else
     return 0;
 }
 int _ilog(unsigned int);
 STIN ogg_int32_t VFLOAT_MULTI(ogg_int32_t a,ogg_int32_t ap,
 				      ogg_int32_t i,
 				      ogg_int32_t *p){
   int ip=_ilog(abs(i))-31;
   return VFLOAT_MULT(a,ap,i<<-ip,ip,p);
 }
 STIN ogg_int32_t VFLOAT_ADD(ogg_int32_t a,ogg_int32_t ap,
 				      ogg_int32_t b,ogg_int32_t bp,
 				      ogg_int32_t *p){
   if(!a){
     *p=bp;
     return b;
   }else if(!b){
     *p=ap;
     return a;
   }
   /* yes, this can leak a bit. */
   if(ap>bp){
     int shift=ap-bp+1;
     *p=ap+1;
     a>>=1;
     if(shift<32){
       b=(b+(1<<(shift-1)))>>shift;
     }else{
       b=0;
     }
   }else{
     int shift=bp-ap+1;
     *p=bp+1;
     b>>=1;
     if(shift<32){
       a=(a+(1<<(shift-1)))>>shift;
     }else{
       a=0;
     }
   }
   a+=b;
   if((a&0xc0000000)==0xc0000000 ||
      (a&0xc0000000)==0){
     a<<=1;
     (*p)--;
   }
   return(a);
 }
 #endif

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media/libtremor/lib/misc.h@6474c204b198 (annotated)

media/libtremor/lib/misc.h