On Sat, 2002-08-03 at 17:36, Nicholas Clark wrote: > cmp r4, #0 > movne ip, #0 > moveq ip, #1 > > how does one teach the optimiser that this is equivalent and 33% faster: > > rsbs ip, r4, #1 > movls ip, #0
Oh, that's rather clever. Look at the compare_scc pattern in arm.md, that's where this stuff all happens. p.
