On Tue, May 8, 2018 at 5:21 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> Since r247992 the cmpelim pass optimizes a few arithmetics with following
> comparisons and some of the peephole2s we have to recognize RMW instructions
> with comparisons don't trigger anymore.
> In particular, on the pr49095.c testcase in GCC 7 only 8 functions used
> load + comparison with arith + store ([fh]*xor, something to look at later),
> while in GCC 8/9 21 further functions do that. This patch restores it to
> the GCC 7 counts.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
> What about GCC 8.2?
>
> 2018-05-08 Jakub Jelinek <ja...@redhat.com>
>
> PR target/85683
> * config/i386/i386.md: Add peepholes for mem {+,-,&,|,^}= x; mem != 0
> after cmpelim optimization.
>
> * gcc.target/i386/pr49095.c: Add -masm=att to dg-options. Add
> scan-assembler-times checking that except for [fh]*xor other functions
> don't use any load instructions.
OK for mainline and backport.
Thanks,
Uros.
