[FFmpeg-cvslog] lavc/flacdsp: R-V V LPC16 function
Rémi Denis-Courmont
git at videolan.org
Sat Nov 18 22:07:04 EET 2023
ffmpeg | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Wed Nov 15 21:31:17 2023 +0200| [ca664f2254a96e9fc9c633fea5eac11f51d93923] | committer: Rémi Denis-Courmont
lavc/flacdsp: R-V V LPC16 function
In this case, the inner loop computing the scalar product can be reduced
to just one multiplication and one sum even with 128-bit vectors. The
result is a lot simpler, but also brings more modest performance gains:
flac_lpc_16_13_c: 15241.0
flac_lpc_16_13_rvv_i32: 11230.0
flac_lpc_16_16_c: 17884.0
flac_lpc_16_16_rvv_i32: 12125.7
flac_lpc_16_29_c: 27847.7
flac_lpc_16_29_rvv_i32: 10494.0
flac_lpc_16_32_c: 30051.5
flac_lpc_16_32_rvv_i32: 10355.0
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ca664f2254a96e9fc9c633fea5eac11f51d93923
---
libavcodec/riscv/flacdsp_init.c | 17 ++++++++++++-----
libavcodec/riscv/flacdsp_rvv.S | 23 +++++++++++++++++++++++
2 files changed, 35 insertions(+), 5 deletions(-)
diff --git a/libavcodec/riscv/flacdsp_init.c b/libavcodec/riscv/flacdsp_init.c
index 0cdbf2fec2..6cfb50ead8 100644
--- a/libavcodec/riscv/flacdsp_init.c
+++ b/libavcodec/riscv/flacdsp_init.c
@@ -25,6 +25,8 @@
#include "libavutil/riscv/cpu.h"
#include "libavcodec/flacdsp.h"
+void ff_flac_lpc16_rvv(int32_t *decoded, const int coeffs[32],
+ int pred_order, int qlevel, int len);
void ff_flac_lpc32_rvv(int32_t *decoded, const int coeffs[32],
int pred_order, int qlevel, int len);
void ff_flac_lpc32_rvv_simple(int32_t *decoded, const int coeffs[32],
@@ -61,16 +63,20 @@ void ff_flac_decorrelate_ms_32_rvv(uint8_t **out, int32_t **in,
av_cold void ff_flacdsp_init_riscv(FLACDSPContext *c, enum AVSampleFormat fmt,
int channels)
{
-#if HAVE_RVV && (__riscv_xlen >= 64)
+#if HAVE_RVV
int flags = av_get_cpu_flags();
if ((flags & AV_CPU_FLAG_RVV_I32) && (flags & AV_CPU_FLAG_RVB_ADDR)) {
int vlenb = ff_get_rv_vlenb();
- if (vlenb == 16)
- c->lpc32 = ff_flac_lpc32_rvv;
- else if (vlenb > 16)
- c->lpc32 = ff_flac_lpc32_rvv_simple;
+ if (vlenb >= 16) {
+ c->lpc16 = ff_flac_lpc16_rvv;
+# if (__riscv_xlen >= 64)
+ if (vlenb > 16)
+ c->lpc32 = ff_flac_lpc32_rvv_simple;
+ else
+ c->lpc32 = ff_flac_lpc32_rvv;
+ }
switch (fmt) {
case AV_SAMPLE_FMT_S16:
@@ -111,6 +117,7 @@ av_cold void ff_flacdsp_init_riscv(FLACDSPContext *c, enum AVSampleFormat fmt,
c->decorrelate[2] = ff_flac_decorrelate_rs_32_rvv;
c->decorrelate[3] = ff_flac_decorrelate_ms_32_rvv;
break;
+# endif
}
}
#endif
diff --git a/libavcodec/riscv/flacdsp_rvv.S b/libavcodec/riscv/flacdsp_rvv.S
index b1724f5500..2a0b50f7a9 100644
--- a/libavcodec/riscv/flacdsp_rvv.S
+++ b/libavcodec/riscv/flacdsp_rvv.S
@@ -20,6 +20,29 @@
#include "libavutil/riscv/asm.S"
+func ff_flac_lpc16_rvv, zve32x
+ vsetvli zero, a2, e32, m8, ta, ma
+ vle32.v v8, (a1)
+ sub a4, a4, a2
+ vle32.v v16, (a0)
+ sh2add a0, a2, a0
+ vmv.s.x v0, zero
+1:
+ vmul.vv v24, v8, v16
+ lw t0, (a0)
+ vredsum.vs v24, v24, v0
+ addi a4, a4, -1
+ vmv.x.s t1, v24
+ sra t1, t1, a3
+ add t0, t0, t1
+ vslide1down.vx v16, v16, t0
+ sw t0, (a0)
+ addi a0, a0, 4
+ bnez a4, 1b
+
+ ret
+endfunc
+
#if (__riscv_xlen == 64)
func ff_flac_lpc32_rvv, zve32x
addi t2, a2, -16
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