> From: Segher Boessenkool <seg...@kernel.crashing.org> > Sent: Thursday, June 6, 2019 4:02 PM > To: Richard Earnshaw (lists) > Cc: Jeff Law; Fredrik Hederstierna; gcc@gcc.gnu.org > Subject: Re: ARM peephole2 from 2003 never merged, still valid > That doesn't stop combine from considering it. It does make that first SET > survive, so that you get a parallel as final insn. It may not like that > one of the parallel SETs is just a move. Needs testcase :-) Hi all, thanks for investigating this, I added semi-stripped testcase in original issue taken from CSiBE teem sources
See attachment in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663 Tested gcc-9.1.0 for ARM 32bit targets, first without peephole2 patch: 00000000 <nrrdRangeSet>: 0: e92d407f push {r0, r1, r2, r3, r4, r5, r6, lr} 4: e2504000 subs r4, r0, #0 8: 0a00003f beq 10c <nrrdRangeSet+0x10c> c: e3510000 cmp r1, #0 10: e1a05001 mov r5, r1 then with new peephole2 patch: 00000000 <nrrdRangeSet>: 0: e92d407f push {r0, r1, r2, r3, r4, r5, r6, lr} 4: e2504000 subs r4, r0, #0 8: 0a00003e beq 108 <nrrdRangeSet+0x108> c: e2515000 subs r5, r1, #0 Thanks, Fredrik
