3 ms·
Why did the compiler even chose to fetch DWORDs only in the first place? It's unclear to me why the accumulator (apparently) determines the vectorization width?
by newgre 2y ago
Why did the compiler even chose to fetch DWORDs only in the first place? It's unclear to me why the accumulator (apparently) determines the vectorization width?
- deleted 2y ago[deleted]
- TinkersW 2y agoThe accumulator is a vector type, with 64 bit sum you can only fit 4 into a 256 bit register. After the loop it will do a horizontal add across the vector register to produce the final scalar result.
- deleted 2y ago[deleted]