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buf_set_buf around 30% speed increase

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Also i have checked the input of this function and in many cases
a simple byte copy is possible.

I have added this check now and is it possible the buffer is
copied byte by byte and not bit by bit.

With byte boundary input the test looks like this:

buf_set_buf 0x02000000 iteration test:
runtime (seconds): old: 6.828559 new: 0.436191 diff: 6.392368
runtime (seconds): old: 6.853636 new: 0.430389 diff: 6.423247
runtime (seconds): old: 6.794985 new: 0.423065 diff: 6.371920

Without:

buf_set_buf 0x02000000 iteration test:
runtime (seconds): old: 6.370869 new: 5.552624 diff: 0.818245
runtime (seconds): old: 6.420730 new: 5.665887 diff: 0.754843
runtime (seconds): old: 6.583306 new: 5.599021 diff: 0.984285

Regards,

Mathias
This commit is contained in:
Mathias K 2011-02-04 21:15:22 +01:00 committed by Øyvind Harboe
parent 5ca7cbe2d2
commit 706284a8fd
1 changed files with 22 additions and 7 deletions
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29
src/helper/binarybuffer.c
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@ -133,19 +133,34 @@ void* buf_set_buf(const void *_src, unsigned src_start,
{
const uint8_t *src = _src;
uint8_t *dst = _dst;
unsigned sb,db,sq,dq;
sb = src_start / 8;
db = dst_start / 8;
sq = src_start % 8;
dq = dst_start % 8;
unsigned src_idx = src_start, dst_idx = dst_start;
for (unsigned i = 0; i < len; i++)
{
if (((src[src_idx / 8] >> (src_idx % 8)) & 1) == 1)
dst[dst_idx / 8] |= 1 << (dst_idx % 8);
if (((*src >> (sq&7)) & 1) == 1)
*dst |= 1 << (dq&7);
else
dst[dst_idx / 8] &= ~(1 << (dst_idx % 8));
dst_idx++;
src_idx++;
*dst &= ~(1 << (dq&7));
if ( sq++ == 7 )
{
sq = 0;
src++;
}
if ( dq++ == 7 )
{
dq = 0;
dst++;
}
}
return dst;
return (uint8_t*)_dst;
}
uint32_t flip_u32(uint32_t value, unsigned int num)