3 ms·
Still waiting for the "Yes, This Time We Really Mean It Fast REP MOVSB" (YTTWRMIFRM) bit. More seriously, if REP MOVSB can be counted on always being the faste
by jabl 6y ago
Still waiting for the "Yes, This Time We Really Mean It Fast REP MOVSB" (YTTWRMIFRM) bit.
More seriously, if REP MOVSB can be counted on always being the fastest method that's fantastic. One thing that easily gets forgotten in microbenchmarking is I$ pollution by those fancy unrolled SIMD loops with 147 special cases.
- magicalhippo 6y agoEver since reading the advice to avoid these CISC-y instructions (IIRC right back to the first Pentium), I've been wondering why. Like what made them not implement the best possible microcode for that? I mean sure for very short loops I guess I can see unrolling being faster than accessing microcode, but yeah.