On 3/29/19 1:44 PM, Jakub Jelinek wrote:
> Hi!
>
> f{char,short,int,long}minus use a RMW instead of direct memory operation
> (regression from 8.3) on ia32. The problem is an extra register copy, which
> regcprop would fix up, but unfortunately peephole2 runs before regcprop.
> Also, in one of the existing peephole2s I've renumbered the operands so that
> we don't overwrite existing operands.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2019-03-29 Jakub Jelinek <ja...@redhat.com>
>
> PR rtl-optimization/89865
> * config/i386/i386.md
> (SWI12 peephole for mem {+,-,&,|,^}= x; mem != 0): Fix up operand
> numbers not to clash with the additional operands[4].
> (peepholes for mem {+,-,&,|,^}= x; mem != 0): New peephole2s
> with extra register copy in the middle.
>
> * gcc.target/i386/pr49095.c: Adjust number of expected RMW spots
> on ia32.
OK. One might ask if there's a way to share a bit of code here since
there's a fair amount of duplication. But I'll trust that you've
pondered that and decided it wasn't really worth the effort.
Jeff
