lavc/vc1dsp: fuse multiply-adds in R-V V inv_trans_4

T-Head C908 (cycles): before after vc1dsp.vc1_inv_trans_4x4_rvv_i32: 128.0 120.0 vc1dsp.vc1_inv_trans_4x8_rvv_i32: 244.0 240.0 vc1dsp.vc1_inv_trans_8x4_rvv_i32: 239.2 235.2
7 months ago · 78e1565f84
parent d69e522523
commit 78e1565f84
1 changed files with 4 additions and 6 deletions
--- a/libavcodec/riscv/vc1dsp_rvv.S
+++ b/libavcodec/riscv/vc1dsp_rvv.S
@ -194,14 +194,12 @@ func ff_vc1_inv_trans_4_rvv, zve32x
        li      t4, 22
        vmul.vx v10, v2, t3
        li      t2, 10
-        vmul.vx v14, v1, t4
+        vmul.vx v26, v1, t4
+        vmul.vx v27, v3, t4
        vadd.vv v24, v8, v10  # t1
        vsub.vv v25, v8, v10  # t2
-        vmul.vx v16, v3, t2
-        vmul.vx v18, v3, t4
-        vmul.vx v20, v1, t2
-        vadd.vv v26, v14, v16 # t3
-        vsub.vv v27, v18, v20 # t4
+        vmacc.vx v26, t2, v3  # t3
+        vnmsac.vx v27, t2, v1 # t4
        vwadd.vv  v8, v24, v26
        vwsub.vv  v10, v25, v27
        vwadd.vv  v12, v25, v27