[FFmpeg-devel] [PATCH 1/2] lavc/bswapdsp: rewrite RISC-V V bswap16
Rémi Denis-Courmont
remi at remlab.net
Sun Jul 16 18:13:51 EEST 2023
This favours bit-wise logic over slow strided stores.
---
libavcodec/riscv/bswapdsp_rvv.S | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/libavcodec/riscv/bswapdsp_rvv.S b/libavcodec/riscv/bswapdsp_rvv.S
index ef2999c1be..8b585ec5c9 100644
--- a/libavcodec/riscv/bswapdsp_rvv.S
+++ b/libavcodec/riscv/bswapdsp_rvv.S
@@ -45,18 +45,17 @@ func ff_bswap32_buf_rvv, zve32x
endfunc
func ff_bswap16_buf_rvv, zve32x
- li t2, 2
- addi t1, a0, 1
1:
- vsetvli t0, a2, e8, m1, ta, ma
- vlseg2e8.v v8, (a1)
- sub a2, a2, t0
- sh1add a1, t0, a1
- vsse8.v v8, (t1), t2
- sh1add t1, t0, t1
- vsse8.v v9, (a0), t2
- sh1add a0, t0, a0
- bnez a2, 1b
+ vsetvli t0, a2, e16, m8, ta, ma
+ vle16.v v8, (a1)
+ sub a2, a2, t0
+ vsll.vi v16, v8, 8
+ sh1add a1, t0, a1
+ vsrl.vi v24, v8, 8
+ vor.vv v8, v16, v24
+ vse16.v v8, (a0)
+ sh1add a0, t0, a0
+ bnez a2, 1b
ret
endfunc
--
2.40.1
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