len0rd/rockbox
1
0
Fork 1
mirror of https://github.com/Rockbox/rockbox.git synced 2025-12-10 05:35:20 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

small speedup for scaler on sh-1, via use of hardware multiply instruction where possible

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20322 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andrew Mahone 2009-03-14 01:41:02 +00:00
parent d88a58bddd
commit f8877bf42d
1 changed files with 14 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

19
apps/recorder/resize.c
View file

@ -60,6 +60,15 @@
#define DEBUGF(...) #define DEBUGF(...)
#endif #endif
#if CONFIG_CPU == SH7034
/* 16*16->32 bit multiplication is a single instrcution on the SH1 */
#define MULUQ(a, b) ((uint32_t) (((uint16_t) (a)) * ((uint16_t) (b))))
#define MULQ(a, b) ((int32_t) (((int16_t) (a)) * ((int16_t) (b))))
#else
#define MULUQ(a, b) ((a) * (b))
#define MULQ(a, b) ((a) * (b))
#endif
/* calculate the maximum dimensions which will preserve the aspect ration of /* calculate the maximum dimensions which will preserve the aspect ration of
src while fitting in the constraints passed in dst, and store result in dst, src while fitting in the constraints passed in dst, and store result in dst,
returning 0 if rounding and 1 if not rounding. returning 0 if rounding and 1 if not rounding.
@ -208,12 +217,12 @@ static bool scale_h_area(void *out_line_ptr,
oxe -= ctx->src->width; oxe -= ctx->src->width;
/* add saved partial pixel from start of area */ /* add saved partial pixel from start of area */
acc = acc * ctx->bm->width + tmp * mul; acc = MULUQ(acc, ctx->bm->width) + MULUQ(tmp, mul);
/* get new pixel , then add its partial coverage to this area */ /* get new pixel , then add its partial coverage to this area */
tmp = *(part->buf); tmp = *(part->buf);
mul = ctx->bm->width - oxe; mul = ctx->bm->width - oxe;
acc += tmp * mul; acc += MULUQ(tmp, mul);
/* round, divide, and either store or accumulate to output row */ /* round, divide, and either store or accumulate to output row */
if (accum) if (accum)
{ {
@ -402,7 +411,7 @@ static bool scale_h_linear(void *out_line_ptr, struct scaler_context *ctx,
ixe -= (ctx->bm->width - 1); ixe -= (ctx->bm->width - 1);
val = *(part->buf); val = *(part->buf);
inc = -val; inc = -val;
val *= (ctx->bm->width - 1); val = MULUQ(val, ctx->bm->width - 1);
ix += 1; ix += 1;
/* If this wasn't the last pixel, add the next one to rgbinc. */ /* If this wasn't the last pixel, add the next one to rgbinc. */
if (ix < (uint32_t)ctx->src->width) { if (ix < (uint32_t)ctx->src->width) {
@ -414,10 +423,10 @@ static bool scale_h_linear(void *out_line_ptr, struct scaler_context *ctx,
/* Add a partial step to rgbval, in this pixel isn't precisely /* Add a partial step to rgbval, in this pixel isn't precisely
aligned with the new source pixel aligned with the new source pixel
*/ */
val += inc * ixe; val += MULQ(inc, ixe);
} }
/* Now multiply the color increment to its proper value */ /* Now multiply the color increment to its proper value */
inc *= ctx->src->width - 1; inc = MULQ(inc, ctx->src->width - 1);
} else } else
val += inc; val += inc;
/* round and scale values, and accumulate or store to output */ /* round and scale values, and accumulate or store to output */