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| author | Nils Wallménius <nils@rockbox.org> | 2010-07-26 23:00:22 +0000 |
|---|---|---|
| committer | Nils Wallménius <nils@rockbox.org> | 2010-07-26 23:00:22 +0000 |
| commit | 30d286d859aad049fb549f48080a196f6074a9fa (patch) | |
| tree | 540fb23031e23da447a0d58e1cb041fc6a311faf /apps | |
| parent | 5dd8c53b960d0b6680a0555a99e3232a5f890d07 (diff) | |
| download | rockbox-30d286d859aad049fb549f48080a196f6074a9fa.tar.gz rockbox-30d286d859aad049fb549f48080a196f6074a9fa.zip | |
libwmapro: slightly shorter and faster inline asm fixed point multiplication routines, speedup is ~0.5%. Also don't lie to gcc about which vars are changed by the asm.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27584 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps')
| -rw-r--r-- | apps/codecs/libwmapro/wmapro_math.h | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/apps/codecs/libwmapro/wmapro_math.h b/apps/codecs/libwmapro/wmapro_math.h index 30b9a987ee..5220560998 100644 --- a/apps/codecs/libwmapro/wmapro_math.h +++ b/apps/codecs/libwmapro/wmapro_math.h @@ -95,37 +95,34 @@ /* Calculates: result = (X*Y)>>16 */ #define fixmul16(X,Y) \ ({ \ - int32_t t1, t2; \ + int32_t t, x = (X); \ asm volatile ( \ - "mac.l %[x],%[y],%%acc0\n\t" /* multiply */ \ - "mulu.l %[y],%[x] \n\t" /* get lower half, avoid emac stall */ \ - "movclr.l %%acc0,%[t1] \n\t" /* get higher half */ \ - "moveq.l #15,%[t2] \n\t" \ - "asl.l %[t2],%[t1] \n\t" /* hi <<= 15, plus one free */ \ - "moveq.l #16,%[t2] \n\t" \ - "lsr.l %[t2],%[x] \n\t" /* (unsigned)lo >>= 16 */ \ - "or.l %[x],%[t1] \n\t" /* combine result */ \ - : [t1]"=&d"(t1), [t2]"=&d"(t2) \ - : [x] "d" ((X)), [y] "d" ((Y))); \ - t1; \ + "mac.l %[x],%[y],%%acc0\n\t" /* multiply */ \ + "mulu.l %[y],%[x] \n\t" /* get lower half, avoid emac stall */ \ + "movclr.l %%acc0,%[t] \n\t" /* get higher half */ \ + "lsr.l #1,%[t] \n\t" /* hi >>= 1 to compensate emac shift */ \ + "move.w %[t],%[x] \n\t" /* combine halfwords */\ + "swap %[x] \n\t" \ + : [t]"=&d"(t), [x] "+d" (x) \ + : [y] "d" ((Y))); \ + x; \ }) /* Calculates: result = (X*Y)>>24 */ #define fixmul24(X,Y) \ ({ \ - int32_t t1, t2; \ + int32_t t, x = (X); \ asm volatile ( \ - "mac.l %[x],%[y],%%acc0\n\t" /* multiply */ \ - "mulu.l %[y],%[x] \n\t" /* get lower half, avoid emac stall */ \ - "movclr.l %%acc0,%[t1] \n\t" /* get higher half */ \ - "moveq.l #7,%[t2] \n\t" \ - "asl.l %[t2],%[t1] \n\t" /* hi <<= 7, plus one free */ \ - "moveq.l #24,%[t2] \n\t" \ - "lsr.l %[t2],%[x] \n\t" /* (unsigned)lo >>= 24 */ \ - "or.l %[x],%[t1] \n\t" /* combine result */ \ - : [t1]"=&d"(t1), [t2]"=&d"(t2) \ - : [x] "d" ((X)), [y] "d" ((Y))); \ - t1; \ + "mac.l %[x],%[y],%%acc0\n\t" /* multiply */ \ + "mulu.l %[y],%[x] \n\t" /* get lower half, avoid emac stall */ \ + "moveq.l #24,%[t] \n\t" \ + "lsr.l %[t],%[x] \n\t" /* (unsigned)lo >>= 24 */ \ + "movclr.l %%acc0,%[t] \n\t" /* get higher half */ \ + "asl.l #7,%[t] \n\t" /* hi <<= 7, plus one free */ \ + "or.l %[x],%[t] \n\t" /* combine result */ \ + : [t]"=&d"(t), [x] "+d" (x) \ + : [y] "d" ((Y))); \ + t; \ }) /* Calculates: result = (X*Y)>>32 */ @@ -239,7 +236,7 @@ static inline void vector_fixmul_scalar(int32_t *dst, const int32_t *src, { int i; for(i=0; i<len; i++) - dst[i] = fixmul24(src[i], mul); + dst[i] = fixmul24(src[i], mul); } static inline int av_clip(int a, int amin, int amax) |