https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93183
rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2020-01-07
CC| |rsandifo at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #2 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org>
---
(In reply to Andrew Pinski from comment #1)
> We get:
> .L3:
> ld1b z0.b, p0/z, [x1, x3]
> movprfx z2, z0
> and z2.b, z2.b, #0xc0
> neg z1.b, p1/m, z0.b ;;; <<<< THIS
> cmpeq p2.b, p1/z, z2.b, #0
> sel z0.b, p2, z0.b, z1.b ;;;; <<<< AND THIS
> st1b z0.b, p0, [x0, x3]
> incb x3
> whilelo p0.b, w3, w2
> b.any .L3
>
> The two instructions marked should be combined.
The problem is that it isn't a straight combination of the
NEG and SEL, because the condition is the inverse of the one
that we want for predication.
This is one of the things that the IFN_COND_* functions were
designed to fix. We should probably add unary versions of those.
