aarch64: me_cmp: Avoid redundant loads in ff_pix_abs16_y2_neon

This avoids one redundant load per row; pix3 from the previous
iteration can be used as pix2 in the next one.

Before:       Cortex A53    A72    A73
pix_abs_0_2_neon:  138.0   59.7   48.0
After:
pix_abs_0_2_neon:  109.7   50.2   39.5

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2022-09-28 11:20:02 +03:00
parent 86519234b8
commit 6f2ad7f951

View File

@ -326,9 +326,9 @@ function ff_pix_abs16_y2_neon, export=1
// w4 int h
// initialize buffers
ld1 {v1.16b}, [x2], x3 // Load pix2
movi v29.8h, #0 // clear the accumulator
movi v28.8h, #0 // clear the accumulator
add x5, x2, x3 // pix2 + stride
cmp w4, #4
b.lt 2f
@ -339,29 +339,25 @@ function ff_pix_abs16_y2_neon, export=1
// avg2(a, b) = (((a) + (b) + 1) >> 1)
// abs(x) = (x < 0 ? (-x) : (x))
ld1 {v1.16b}, [x2], x3 // Load pix2 for first iteration
ld1 {v2.16b}, [x5], x3 // Load pix3 for first iteration
ld1 {v2.16b}, [x2], x3 // Load pix3 for first iteration
ld1 {v0.16b}, [x1], x3 // Load pix1 for first iteration
urhadd v30.16b, v1.16b, v2.16b // Rounding halving add, first iteration
ld1 {v4.16b}, [x2], x3 // Load pix2 for second iteration
ld1 {v5.16b}, [x5], x3 // Load pix3 for second iteartion
ld1 {v5.16b}, [x2], x3 // Load pix3 for second iteartion
uabal v29.8h, v0.8b, v30.8b // Absolute difference of lower half, first iteration
uabal2 v28.8h, v0.16b, v30.16b // Absolute difference of upper half, first iteration
ld1 {v3.16b}, [x1], x3 // Load pix1 for second iteration
urhadd v27.16b, v4.16b, v5.16b // Rounding halving add, second iteration
ld1 {v7.16b}, [x2], x3 // Load pix2 for third iteration
ld1 {v20.16b}, [x5], x3 // Load pix3 for third iteration
urhadd v27.16b, v2.16b, v5.16b // Rounding halving add, second iteration
ld1 {v20.16b}, [x2], x3 // Load pix3 for third iteration
uabal v29.8h, v3.8b, v27.8b // Absolute difference of lower half for second iteration
uabal2 v28.8h, v3.16b, v27.16b // Absolute difference of upper half for second iteration
ld1 {v6.16b}, [x1], x3 // Load pix1 for third iteration
urhadd v26.16b, v7.16b, v20.16b // Rounding halving add, third iteration
ld1 {v22.16b}, [x2], x3 // Load pix2 for fourth iteration
ld1 {v23.16b}, [x5], x3 // Load pix3 for fourth iteration
urhadd v26.16b, v5.16b, v20.16b // Rounding halving add, third iteration
ld1 {v1.16b}, [x2], x3 // Load pix3 for fourth iteration
uabal v29.8h, v6.8b, v26.8b // Absolute difference of lower half for third iteration
uabal2 v28.8h, v6.16b, v26.16b // Absolute difference of upper half for third iteration
ld1 {v21.16b}, [x1], x3 // Load pix1 for fourth iteration
sub w4, w4, #4 // h-= 4
urhadd v25.16b, v22.16b, v23.16b // Rounding halving add
urhadd v25.16b, v20.16b, v1.16b // Rounding halving add
cmp w4, #4
uabal v29.8h, v21.8b, v25.8b // Absolute difference of lower half for fourth iteration
uabal2 v28.8h, v21.16b, v25.16b // Absolute difference of upper half for fourth iteration
@ -372,11 +368,11 @@ function ff_pix_abs16_y2_neon, export=1
// iterate by one
2:
ld1 {v1.16b}, [x2], x3 // Load pix2
ld1 {v2.16b}, [x5], x3 // Load pix3
ld1 {v2.16b}, [x2], x3 // Load pix3
subs w4, w4, #1
ld1 {v0.16b}, [x1], x3 // Load pix1
urhadd v30.16b, v1.16b, v2.16b // Rounding halving add
mov v1.16b, v2.16b // Shift pix3->pix2
uabal v29.8h, v30.8b, v0.8b
uabal2 v28.8h, v30.16b, v0.16b