[Bug target/115842] [15 Regression] 6.5% slowdown of 548.exchange2_r on Intel Ice Lake

[liuhongt at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115842

--- Comment #3 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
(In reply to Hongtao Liu from comment #2)
> Bisected to r15-1673-gb8153b5417bed0, the commit fixed wrong rtx_cost of
> r15-882-g1d6199e5f8c1c0 which happened to improved 548.exchange_r.

Looks like wrong rtx_cost of mem somehow get better RA and has less spills in
the hot loop.