Improve a couple loops

Avoid masking the index with each iteration, and instead do up to when the mask
would apply. This allows for better optimizations, in particular fewer
instructions and better chances for vectorization.
This commit is contained in:
Chris Robinson 2018-09-29 18:48:28 -07:00
parent 32494e72a5
commit d5a78f0843

View File

@ -18,7 +18,7 @@ extern inline ALuint GetCompressorSampleRate(const Compressor *Comp);
*
* http://www.richardhartersworld.com/cri/2001/slidingmin.html
*/
static ALfloat UpdateSlidingHold(SlidingHold *Hold, const ALsizei i, const ALfloat in)
ALfloat UpdateSlidingHold(SlidingHold *Hold, const ALsizei i, const ALfloat in)
{
const ALsizei mask = BUFFERSIZE - 1;
const ALsizei length = Hold->Length;
@ -38,8 +38,14 @@ static ALfloat UpdateSlidingHold(SlidingHold *Hold, const ALsizei i, const ALflo
}
else
{
while(in >= values[lowerIndex])
lowerIndex = (lowerIndex - 1) & mask;
do {
do {
if(!(in >= values[lowerIndex]))
goto found_place;
} while(lowerIndex--);
lowerIndex = mask;
} while(1);
found_place:
lowerIndex = (lowerIndex + 1) & mask;
values[lowerIndex] = in;
@ -54,16 +60,18 @@ static ALfloat UpdateSlidingHold(SlidingHold *Hold, const ALsizei i, const ALflo
static void ShiftSlidingHold(SlidingHold *Hold, const ALsizei n)
{
const ALsizei mask = BUFFERSIZE - 1;
const ALsizei lowerIndex = Hold->LowerIndex;
ALsizei *restrict expiries = Hold->Expiries;
ALsizei i = Hold->UpperIndex;
while(i != lowerIndex)
if(lowerIndex < i)
{
for(;i != BUFFERSIZE;i++)
expiries[i] -= n;
i = (i + 1) & mask;
i = 0;
}
for(;i != lowerIndex;i++)
expiries[i] -= n;
expiries[i] -= n;
}