On Saturday 11 September 2010 15:31:10 Siarhei Siamashka wrote:
> + else if (src >= (src << 8) && src >= (src << 16) && src >= (src << 24))
> + {
> + /* non-additive blending */
Sigh...
Somehow overlooked it, and the faster code path was actually not always taken
when it could. This check should have been"if (src >= (src << 8) &&
(src | 0xFF0000) >= (src << 16) && src >= (src << 24))".
This can be verified by the following test program:
/**********/
#include <assert.h>
#include <stdint.h>
int main()
{
uint32_t src;
for (src = 0; src < 0xFFFFFFFF; src++)
{
int check1 = (src >= (src << 8) && (src | 0xFF0000) >= (src << 16) &&
src >= (src << 24));
int check2 = ((src & 0xFF000000) >= ((src << 8) & 0xFF000000) &&
(src & 0xFF000000) >= ((src << 16) & 0xFF000000) &&
(src & 0xFF000000) >= ((src << 24) & 0xFF000000));
assert (check1 == check2);
}
return 0;
}
/**********/
--
Best regards,
Siarhei Siamashka
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