https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
Andrew Stubbs changed:
What|Removed |Added
Priority|P3 |P5
Severity|critical
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
--- Comment #6 from Andrew Stubbs ---
(In reply to Richard Biener from comment #4)
> Btw, isn't the issue that the reduction looks at all lanes? That is,
> I think the code simply assumes that for fully masked loops at least
> one iteration is p
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
--- Comment #5 from Richard Biener ---
And the issue is to be fixed in vect_create_epilog_for_reduction where
we create the index IV:
/* For cond reductions we want to create a new vector (INDEX_COND_EXPR)
which is updated with the curren
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
--- Comment #4 from Richard Biener ---
IIRC AVX512 also implements fully masked loops so the testcase should fail
there, too, if we adjust N accordingly (to 15 or 31). Hmm, can't seem to
trigger
the fully masked support here, maybe I misremember
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
--- Comment #3 from Andrew Stubbs ---
The GCN architecture can handle the masking, but I don't know how we'd
represent or apply that in the middle end?
I can probably implement extract_last, and that might be more efficient, but I
don't see how
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
--- Comment #2 from rsandifo at gcc dot gnu.org
---
(In reply to Richard Biener from comment #1)
> Looks like cond-reduction cannot handle fully masked loops unless we'd
> somehow mask the condition operation itself?
Yeah, looks like it. We'd
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92772
Richard Biener changed:
What|Removed |Added
Keywords||wrong-code
Target|
