On Wed, 2020-04-22 at 07:59 -0500, Segher Boessenkool wrote: > Hi! > > On Tue, Apr 21, 2020 at 04:53:53PM -0500, Aaron Sawdey via Gcc- > patches wrote: > > For future architecture with prefix instructions, always use > > plq/pstq > > rather than lq/stq for atomic load of quadword. Then we never have > > to > > do the doubleword swap on little endian. Before this fix, -mno- > > pcrel > > would generate lq with the doubleword swap (which was ok) and > > -mpcrel > > would generate plq, also with the doubleword swap, which was wrong. > > 2020-04-20 Aaron Sawdey <acsaw...@linux.ibm.com> > > > > PR target/94622 > > * config/rs6000/sync.md (load_quadpti): Add attr "prefixed" > > if TARGET_PREFIXED. > > (store_quadpti): Ditto. > > (atomic_load<mode>): Do not swap doublewords if TARGET_PREFIXED > > as > > plq will be used and doesn't need it. > > (atomic_store<mode>): Ditto, for pstq. > > +;; Pattern load_quadpti will always use plq for atomic TImode if > > +;; TARGET_PREFIXED. It has the correct doubleword ordering on > > either LE > > +;; or BE, so we can just move the result into the output register > > and > > +;; do not need to do the doubleword swap for LE. Also this avoids > > any > > +;; confusion about whether the lq vs plq might be used based on > > whether > > +;; op1 has PC-relative addressing. We could potentially allow BE > > to > > +;; use lq because it doesn't have the doubleword ordering problem. > > Two spaces after dot (twice). > > Thanks for the nice comments :-) > > > - [(set_attr "type" "store")]) > > + [(set_attr "type" "store") > > + (set (attr "prefixed") (if_then_else (match_test > > "TARGET_PREFIXED") > > + (const_string "yes") > > + (const_string "no")))]) > > Every 8 leading spaces should be a tab (it's annoying to have a > mixture > of styles, and then later to have patches randomly change such things > as > well. Spaces everywhere (no tabs ever) works fine for me, but that > is > not what we use, not in GCC, and not in our port. We could change > that > in GCC 11 perhaps? Opinions?)
Keep the port consistent with the rest of the project, whatever it is. I tend to prefer just tabs, but also like to have >80 column windows. :-) thanks -Will > > The patch is okay for trunk modulo those nits. Thanks! > > > Segher
