So I run profiler and 97% of time is spent in void twinsSieve
function and hotspots are seg[k] = seg[k] | 1; lines. Since
seg[k] can only be 1 or 0 I removed that or operation. And the
results are. Queue the drum-roll... 5% slower.
I thought that all of my studying was getting somewhere. That I
beginning to understand things but no. Performing OR operation
and then storing data is faster than just storing data. [sarcasm]
Of course it makes sense [/sarcasm]
I looked at assembler and nothing changed except
orb $0x1,(%rbx,%rdi,1)
is changed to
movb $0x1,(%rbx,%rdi,1)
I`m completely lost.
