From 9b4655c3a145d5d0f315c3bd0a80792f37603c2f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= Date: Thu, 25 Jul 2024 17:40:26 +0300 Subject: [PATCH] lavc/vp8dsp: use saturating add/sub for R-V V DC add T-Head C908 (cycles): vp7_idct_dc_add_c: 108.5 vp7_idct_dc_add_rvv_i32: 56.2 (before) vp7_idct_dc_add_rvv_i32: 47.2 (after) vp8_idct_dc_add_c: 96.2 vp8_idct_dc_add_rvv_i32: 43.0 (before) vp8_idct_dc_add_rvv_i32: 34.0 (after) --- libavcodec/riscv/vp8dsp_rvv.S | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/libavcodec/riscv/vp8dsp_rvv.S b/libavcodec/riscv/vp8dsp_rvv.S index 6ff443fbe6..a8b3e239ba 100644 --- a/libavcodec/riscv/vp8dsp_rvv.S +++ b/libavcodec/riscv/vp8dsp_rvv.S @@ -172,12 +172,18 @@ func ff_vp78_idct_dc_add_rvv, zve32x vsetivli zero, 4, e8, mf4, ta, ma sh zero, (a1) vlse32.v v8, (a0), a2 - vsetivli zero, 16, e16, m2, ta, ma - vzext.vf2 v16, v8 - vadd.vx v16, v16, a3 - vmax.vx v16, v16, zero - vsetvli zero, zero, e8, m1, ta, ma - vnclipu.wi v8, v16, 0 + vsetivli zero, 16, e8, m1, ta, ma + bgez a3, 1f + + # block[0] < 0 + neg a3, a3 + vssubu.vx v8, v8, a3 + vsetivli zero, 4, e8, mf4, ta, ma + vsse32.v v8, (a0), a2 + ret + +1: # block[0] >= 0 + vsaddu.vx v8, v8, a3 vsetivli zero, 4, e8, mf4, ta, ma vsse32.v v8, (a0), a2 ret