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lavu/float_dsp: optimise R-V V fmul_reverse & fmul_window 

Roll the loop to avoid slow gathers.

Before:
vector_fmul_reverse_c:       1561.7
vector_fmul_reverse_rvv_f32: 2410.2
vector_fmul_window_c:        2068.2
vector_fmul_window_rvv_f32:  1879.5

After:
vector_fmul_reverse_c:       1561.7
vector_fmul_reverse_rvv_f32:  916.2
vector_fmul_window_c:        2068.2
vector_fmul_window_rvv_f32:  1202.5
This commit is contained in:
Rémi Denis-Courmont 2023-11-19 13:36:01 +02:00
parent 3a134e8299
commit e49f41fb27
1 changed files with 8 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
libavutil/riscv/float_dsp_rvv.S
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@ -75,18 +75,19 @@ endfunc
func ff_vector_fmul_window_rvv, zve32f
// a0: dst, a1: src0, a2: src1, a3: window, a4: length
vsetvli t0, zero, e16, m2, ta, ma
// e16/m2 and e32/m4 are possible but slower due to gather.
vsetvli t0, zero, e16, m1, ta, ma
sh2add a2, a4, a2
vid.v v0
sh3add t3, a4, a3
vadd.vi v0, v0, 1
sh3add t0, a4, a0
1:
vsetvli t2, a4, e16, m2, ta, ma
vsetvli t2, a4, e16, m1, ta, ma
slli t4, t2, 2
vrsub.vx v2, v0, t2
sub t3, t3, t4
vsetvli zero, zero, e32, m4, ta, ma
vsetvli zero, zero, e32, m2, ta, ma
sub a2, a2, t4
vle32.v v8, (t3)
sub t0, t0, t4
@ -133,16 +134,17 @@ endfunc
// TODO factor vrsub, separate last iteration?
// (a0) = (a1) * reverse(a2) [0..a3-1]
func ff_vector_fmul_reverse_rvv, zve32f
vsetvli t0, zero, e16, m4, ta, ma
// e16/m4 and e32/m8 are possible but slower due to gather.
vsetvli t0, zero, e16, m1, ta, ma
sh2add a2, a3, a2
vid.v v0
vadd.vi v0, v0, 1
1:
vsetvli t0, a3, e16, m4, ta, ma
vsetvli t0, a3, e16, m1, ta, ma
slli t1, t0, 2
vrsub.vx v4, v0, t0 // v4[i] = [VL-1, VL-2... 1, 0]
sub a2, a2, t1
vsetvli zero, zero, e32, m8, ta, ma
vsetvli zero, zero, e32, m2, ta, ma
vle32.v v8, (a2)
sub a3, a3, t0
vle32.v v16, (a1)