Hello,
I have the following 3 functions that utilize NEON instruction set:
function pixel_avg2_w8_neon, export=1 1: subs w5, w5, #2 ld1 {v0.8b}, [x2], x3 ld1 {v2.8b}, [x4], x3 urhadd v0.8b, v0.8b, v2.8b ld1 {v1.8b}, [x2], x3 ld1 {v3.8b}, [x4], x3 urhadd v1.8b, v1.8b, v3.8b st1 {v0.8b}, [x0], x1 st1 {v1.8b}, [x0], x1 b.gt 1b ret endfunc
function pixel_avg2_w16_neon, export=1 1: subs w5, w5, #2 ld1 {v0.16b}, [x2], x3 ld1 {v2.16b}, [x4], x3 urhadd v0.16b, v0.16b, v2.16b ld1 {v1.16b}, [x2], x3 ld1 {v3.16b}, [x4], x3 urhadd v1.16b, v1.16b, v3.16b st1 {v0.16b}, [x0], x1 st1 {v1.16b}, [x0], x1 b.gt 1b ret endfunc
function pixel_sad_\h\()_neon, export=1 ld1 {v1.16b}, [x2], x3 ld1 {v0.16b}, [x0], x1 ld1 {v3.16b}, [x2], x3 ld1 {v2.16b}, [x0], x1 uabdl v16.8h, v0.8b, v1.8b uabdl2 v17.8h, v0.16b, v1.16b uabal v16.8h, v2.8b, v3.8b uabal2 v17.8h, v2.16b, v3.16b .rept \h / 2 - 1 ld1 {v1.16b}, [x2], x3 ld1 {v0.16b}, [x0], x1 ld1 {v3.16b}, [x2], x3 ld1 {v2.16b}, [x0], x1 uabal v16.8h, v0.8b, v1.8b uabal2 v17.8h, v0.16b, v1.16b uabal v16.8h, v2.8b, v3.8b uabal2 v17.8h, v2.16b, v3.16b .endr add v16.8h, v16.8h, v17.8h uaddlv s0, v16.8h fmov w0, s0 ret endfunc
I want to use SVE/SVE2 instructions set to improve the performance of these functions. My testbed is Alibaba Yitian 710 (vector size=128 bits).
For the first 2, I couldn't find a way to improve the performance. For the latter, I wrote the following function:
function pixel_sad_\h\()_sve, export=1 ptrue p0.h, vl8 ld1b {z1.h}, p0/z, [x2] ld1b {z4.h}, p0/z, [x2, #1, mul vl] add x2, x2, x3 ld1b {z3.h}, p0/z, [x2] ld1b {z6.h}, p0/z, [x2, #1, mul vl] add x2, x2, x3 ld1b {z0.h}, p0/z, [x0] ld1b {z5.h}, p0/z, [x0, #1, mul vl] add x0, x0, x1 ld1b {z2.h}, p0/z, [x0] ld1b {z7.h}, p0/z, [x0, #1, mul vl] add x0, x0, x1 uabd v16.8h, v0.8h, v1.8h uabd v17.8h, v4.8h, v5.8h uaba v16.8h, v2.8h, v3.8h uaba v17.8h, v7.8h, v6.8h .rept \h / 2 - 1 ld1b {z1.h}, p0/z, [x2] ld1b {z4.h}, p0/z, [x2, #1, mul vl] add x2, x2, x3 ld1b {z3.h}, p0/z, [x2] ld1b {z6.h}, p0/z, [x2, #1, mul vl] add x2, x2, x3 ld1b {z0.h}, p0/z, [x0] ld1b {z5.h}, p0/z, [x0, #1, mul vl] add x0, x0, x1 ld1b {z2.h}, p0/z, [x0] ld1b {z7.h}, p0/z, [x0, #1, mul vl] add x0, x0, x1 uaba v16.8h, v0.8h, v1.8h uaba v17.8h, v4.8h, v5.8h uaba v16.8h, v2.8h, v3.8h uaba v17.8h, v7.8h, v6.8h .endr add v16.8h, v16.8h, v17.8h uaddlv s0, v16.8h fmov w0, s0 ret endfunc
However, this degrades the performance instead of improving it.
Can someone help me?
Thank you in advance,
Akis