/media/libtremor/lib/misc.h
http://github.com/zpao/v8monkey · C Header · 250 lines · 163 code · 43 blank · 44 comment · 10 complexity · 578475bf245c6be56e2afbd357643272 MD5 · raw file
- /********************************************************************
- * *
- * 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