On Fri, Mar 31, 2023 at 1:57 PM Uros Bizjak <ubiz...@gmail.com> wrote: > > On Fri, Mar 31, 2023 at 7:11 AM liuhongt <hongtao....@intel.com> wrote: > > > > RA sometimes will use lowest the cost of the mode with all different > > regclasses > > w/o check if it's hard_regno_mode_ok. > > It's impossible to put modes whose size > 8 into MASK_REGS, ajdust the cost > > to > > avoid potential performance issue. > > I was going to ask to open a PR in order to fix RA instead of the > proposed workaround, but the patch just prevents a theoretical issue > and follows the established practice with other regclasses. Perhaps > these workarounds are not needed with the current RA, but this is a > tangential issue which should be fixed for all regclasses. Opened https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109351 > > > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. > > Ok for trunk? > > OK. > > Thanks, > Uros. > > > > > gcc/ChangeLog: > > > > * config/i386/i386.cc (inline_memory_move_cost): Return 100 > > for MASK_REGS when MODE_SIZE > 8. > > --- > > gcc/config/i386/i386.cc | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc > > index 2cc8e9548a9..2581b800a06 100644 > > --- a/gcc/config/i386/i386.cc > > +++ b/gcc/config/i386/i386.cc > > @@ -19847,9 +19847,12 @@ inline_memory_move_cost (machine_mode mode, enum > > reg_class regclass, int in) > > index = 1; > > break; > > /* DImode loads and stores assumed to cost the same as SImode. */ > > - default: > > + case 4: > > + case 8: > > index = 2; > > break; > > + default: > > + return 100; > > } > > > > if (in == 2) > > -- > > 2.39.1.388.g2fc9e9ca3c > >
-- BR, Hongtao
