https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101609
Bug ID: 101609
Summary: no right shift pattern for vector(2) long long on
aarch64
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Target: aarch64*-*-*
Take:
#define SIZE 16
typedef long long veci __attribute__((vector_size(SIZE)));
void f(veci &a, veci &b, veci &c){
c= a>>b;
}
----- CUT ----
We currently produce:
ldr q1, [x1]
ldr q0, [x0]
fmov d3, d1
dup d1, v1.d[1]
fmov d2, d0
dup d0, v0.d[1]
neg d4, d3
sshl d4, d2, d4
neg d2, d1
sshl d2, d0, d2
fmov x1, d4
fmov x0, d2
stp x1, x0, [x2]
ret
----- CUT ----
But we should be able to do:
ldr q0, [x1]
ldr q1, [x0]
neg v0.2d, v0.2d
sshl v0.2d, v1.2d, v0.2d
str q0, [x2]
