https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115602
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rsandifo at gcc dot gnu.org
Keywords| |missed-optimization
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ah, interesting - somehow we managed to create a self-referencing cycle!?
t.c:13:6: note: node 0x4ab34e0 (max_nunits=1, refcnt=3) vector(2) double
t.c:13:6: note: op: VEC_PERM_EXPR
t.c:13:6: note: stmt 0 _11 = gvevent_motion_job.zoom;
t.c:13:6: note: stmt 1 _11 = gvevent_motion_job.zoom;
t.c:13:6: note: lane permutation { 0[1] 0[0] }
t.c:13:6: note: children 0x4ab34e0
that's because this permute is the same as the load that was originally
feeding it:
t.c:13:6: note: node 0x4ab3690 (max_nunits=2, refcnt=1) vector(2) double
t.c:13:6: note: op template: _11 = gvevent_motion_job.zoom;
t.c:13:6: note: stmt 0 _11 = gvevent_motion_job.zoom;
t.c:13:6: note: stmt 1 _11 = gvevent_motion_job.zoom;
t.c:13:6: note: load permutation { 2 2 }
that's a missed optimization caused by the SLP optimize pass which inserts
this permute as compensation.
Richard - can you look where to best see that uniform nodes (through a
uniform load permute) do not require a permute?
I'll see to somehow make CSE robust against this.
