misc: Prevent Vec_IntRemove from loading nSize in every iteration#508
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mshockwave wants to merge 1 commit into
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misc: Prevent Vec_IntRemove from loading nSize in every iteration#508mshockwave wants to merge 1 commit into
mshockwave wants to merge 1 commit into
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This seemly benign loop ``` for ( i++; i < p->nSize; i++ ) p->pArray[i-1] = p->pArray[i]; ``` will actually load `p->nSize` in every loop iteration (rather than memorizing the value) due to some unfortunate pointer aliasing properties in C/C++. As Vec_IntRemove is quite ubiquitous, this extra memory load actually causes visible performance impact and prevents further optimizations on the loop. This patch fixes this by factoring `p->nSize` out of the loop.
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This seemly benign loop
will actually load
p->nSizein every loop iteration (rather than memorizing the value) due to some unfortunate pointer aliasing properties in C/C++. AsVec_IntRemoveis quite ubiquitous, this extra memory load actually causes visible performance impact and prevents further optimizations on the loop.This patch fixes this by factoring
p->nSizeout of the loop.