https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102977
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Huh.
The trunk code is vectorized all the way:
ptrue p1.h, vl8 ; set p1.h to 8 wide
ptrue p0.b, all ; set p0.b to all ones
ld2h {z2.h - z3.h}, p1/z, [x1] ; load the 8x2 vector into z2/z3
ld2h {z0.h - z1.h}, p1/z, [x2] ; load the 8x2 vector into z0/z1
ld2h {z16.h - z17.h}, p1/z, [x0] ; load the 8x2 vector into z16/17
fmul z6.h, z0.h, z3.h ; z6 = z0 * z3
movprfx z7, z16 ; z7 = z16
fmla z7.h, p0/m, z0.h, z2.h ; z7+=z0*z2
fmla z6.h, p0/m, z1.h, z2.h ; z6 += z1*z2
movprfx z4, z7 ; z4 = z7
fmls z4.h, p0/m, z1.h, z3.h ; z4 -= z1*z3
fadd z5.h, z6.h, z17.h ; z5 = z6 + z17
st2h {z4.h - z5.h}, p1, [x0] ; store the 8x2 vector into x0
note the way ld2 works is the first element goes into the first vector, second
element goes into the second vector, the 3rd element goes into the first
vector, the 4th element goes into the second vector.
So this is optimized all the way. Knowing the lower limit of the size of the
vectors will be 128 byte (or 64 half floats) so 8 half floats will always fit
into one vector just fine.
So this is vectorized all the way such that it is unrolled even.
