This uses a more traditional approach allowing up processing of up to
period minus two elements per iteration. This also allows the algorithm
to work for all and any vector length.
As the T-Head C908 device under test can load 16 elements loop, there is
unsurprisingly a little performance drop when the period is minimal and
the parallelism is capped at 13 elements:
Before:
postfilter_15_c: 21222.2
postfilter_15_rvv_f32: 22007.7
postfilter_512_c:20189.7
postfilter_512_rvv_f32: 22004.2
postfilter_1022_c: 20189.7
postfilter_1022_rvv_f32: 22004.2
After:
postfilter_15_c: 20189.5
postfilter_15_rvv_f32:7057.2
postfilter_512_c:20189.5
postfilter_512_rvv_f32: 5667.2
postfilter_1022_c: 20192.7
postfilter_1022_rvv_f32: 5667.2
---
libavcodec/riscv/opusdsp_init.c | 22 ++---
libavcodec/riscv/opusdsp_rvv.S | 87 +++--
2 files changed, 42 insertions(+), 67 deletions(-)
diff --git a/libavcodec/riscv/opusdsp_init.c b/libavcodec/riscv/opusdsp_init.c
index 7fde9b1fa8..f5a842a326 100644
--- a/libavcodec/riscv/opusdsp_init.c
+++ b/libavcodec/riscv/opusdsp_init.c
@@ -25,30 +25,14 @@
#include "libavutil/riscv/cpu.h"
#include "libavcodec/opusdsp.h"
-void ff_opus_postfilter_rvv_128(float *data, int period, float *g, int len);
-void ff_opus_postfilter_rvv_256(float *data, int period, float *g, int len);
-void ff_opus_postfilter_rvv_512(float *data, int period, float *g, int len);
-void ff_opus_postfilter_rvv_1024(float *data, int period, float *g, int len);
+void ff_opus_postfilter_rvv(float *data, int period, float *g, int len);
av_cold void ff_opus_dsp_init_riscv(OpusDSP *d)
{
#if HAVE_RVV
int flags = av_get_cpu_flags();
-if (flags & AV_CPU_FLAG_RVV_F32)
-switch (ff_get_rv_vlenb()) {
-case 16:
-d->postfilter = ff_opus_postfilter_rvv_128;
-break;
-case 32:
-d->postfilter = ff_opus_postfilter_rvv_256;
-break;
-case 64:
-d->postfilter = ff_opus_postfilter_rvv_512;
-break;
-case 128:
-d->postfilter = ff_opus_postfilter_rvv_512;
-break;
-}
+if ((flags & AV_CPU_FLAG_RVV_F32) && (flags & AV_CPU_FLAG_RVB_ADDR))
+d->postfilter = ff_opus_postfilter_rvv;
#endif
}
diff --git a/libavcodec/riscv/opusdsp_rvv.S b/libavcodec/riscv/opusdsp_rvv.S
index b3d23a9de5..79ae86c30e 100644
--- a/libavcodec/riscv/opusdsp_rvv.S
+++ b/libavcodec/riscv/opusdsp_rvv.S
@@ -20,56 +20,47 @@
#include "libavutil/riscv/asm.S"
-func ff_opus_postfilter_rvv_128, zve32f
-lvtypei a5, e32, m2, ta, ma
-j 1f
-endfunc
-
-func ff_opus_postfilter_rvv_512, zve32f
-lvtypei a5, e32, mf2, ta, ma
-j 1f
-endfunc
+func ff_opus_postfilter_rvv, zve32f
+flw fa0, 0(a2) // g0
+sllit1, a1, 2
+flw fa1, 4(a2) // g1
+sub t0, a0, t1
+flw fa2, 8(a2) // g2
+addit0, t0, 2 * 4 // data - (period - 2) = initial
-func ff_opus_postfilter_rvv_1024, zve32f
-lvtypei a5, e32, mf4, ta, ma
-j 1f
-endfunc
-
-func ff_opus_postfilter_rvv_256, zve32f
-lvtypei a5, e32, m1, ta, ma
+flw ft4, -16(t0)
+addit3, a1, -2 // maximum parallelism w/o stepping our tail
+flw ft3, -12(t0)
+flw ft2, -8(t0)
+flw ft1, -4(t0)
1:
-li a4, 5
-addi a1, a1, 2
-slli a1, a1, 2
-lw t1, 4(a2)
-vsetivli zero, 3, e32, m1, ta, ma
-vle32.v v24, (a2)
-sub a1, a0, a1 // a1 = = [-(period + 2)]
-vsetvl zero, a4, a5
-vslide1up.vx v8, v24, t1
-lw t2, 8(a2)
-vle32.v v16, (a1)
-vslide1up.vx v24, v8, t2 // v24 = { g[2], g[1], g[0], g[1], g[2] }
-2:
-vsetvl t0, a3, a5
-vle32.v v0, (a0)
-sub a3, a3, t0
-3:
-vsetvl zero, a4, a5
-lw t2, 20(a1)
-vfmul.vv v8, v24, v16
-addi a0, a0, 4
-vslide1down.vx v16, v16, t2
-addi a1, a1, 4
-vfredusum.vs v0, v8, v0
-vsetvl zero, t0, a5
-vmv.x.st1, v0
-addi t0, t0, -1
-vslide1down.vx v0, v0, zero
-sw t1, -4(a0)
-bnez t0, 3b
-
-bneza3, 2b
+min t1, a3, t3
+vsetvli t1, t1, e32, m4, ta, ma
+vle32.v v0, (t0) // x0
+sub a3, a3, t1
+vle32.v v28, (a0)
+sh2add t0, t1, t0
+vfslide1up.vf v4, v0, ft1
+addit2, t1, -4
+vfslide1up.vf v8, v4, ft2
+vfslide1up.vf v12, v8, ft3
+vfslide1up.vf v16, v12, ft4
+vfadd.vv v20, v4, v12
+vfadd.vv v24, v0, v16
+vslidedown.vx v12, v0, t2
+vfmacc.vf v28, fa0, v8
+
