diff options
Diffstat (limited to 'misc.h')
| -rw-r--r-- | misc.h | 57 |
1 files changed, 57 insertions, 0 deletions
@@ -79,6 +79,63 @@ static inline ogg_int32_t CLIP_TO_15(ogg_int32_t x) { return(ret); } +/* + * 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)=(MULT32(_a,_t)+MULT32(_b,_v))<<1; \ + *(_y)=(MULT32(_b,_t)-MULT32(_a,_v))<<1; } +#define XNPROD31(_a, _b, _t, _v, _x, _y) \ + { *(_x)=(MULT32(_a,_t)-MULT32(_b,_v))<<1; \ + *(_y)=(MULT32(_b,_t)+MULT32(_a,_v))<<1; } + +#else + +static inline 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); +} + +static inline 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 = (MULT32(a, t) + MULT32(b, v))<<1; + *y = (MULT32(b, t) - MULT32(a, v))<<1; +} + +static inline 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 = (MULT32(a, t) - MULT32(b, v))<<1; + *y = (MULT32(b, t) + MULT32(a, v))<<1; +} + +#endif + #endif static inline ogg_int32_t VFLOAT_MULT(ogg_int32_t a,ogg_int32_t ap, |