swscale/aarch64: use multiply accumulate and shift-right narrow

[ffmpeg] / libswscale / aarch64 / output.S

diff --git a/libswscale/aarch64/output.S b/libswscale/aarch64/output.S
index 90d3b57b103802acd9db6e56b86a564cf83c80b1..25bf28b6e4d38559a250ee939b7a3533f778b6ad 100644 (file)
--- a/libswscale/aarch64/output.S
+++ b/libswscale/aarch64/output.S
@@ -38,29 +38,21 @@ function ff_yuv2planeX_8_neon, export=1
         add                 x12, x12, x7, lsl #1            // &src[j+1][i]
         ld1                 {v5.8H}, [x11]                  // read 8x16-bit @ src[j  ][i + {0..7}]: A,B,C,D,E,F,G,H
         ld1                 {v6.8H}, [x12]                  // read 8x16-bit @ src[j+1][i + {0..7}]: I,J,K,L,M,N,O,P
-        ldr                 w11, [x10], #4                  // read 2x16-bit coeffs (X, Y) at (filter[j], filter[j+1])
-        zip1                v16.8H, v5.8H, v6.8H            // A,I,B,J,C,K,D,L
-        zip2                v17.8H, v5.8H, v6.8H            // E,M,F,N,F,O,H,P
-        dup                 v7.4S, w11                      // X,Y,X,Y,X,Y,X,Y
-        smull               v18.4S, v16.4H, v7.4H           // A.X I.Y B.X J.Y
-        smull               v20.4S, v17.4H, v7.4H           // E.X M.Y F.X N.Y
-        smull2              v19.4S, v16.8H, v7.8H           // C.X K.Y D.X L.Y
-        smull2              v21.4S, v17.8H, v7.8H           // G.X O.Y H.X P.Y
-        addp                v16.4S, v18.4S, v19.4S          // A.X+I.Y B.X+J.Y C.X+K.Y D.X+L.Y
-        addp                v17.4S, v20.4S, v21.4S          // E.X+M.Y F.X+N.Y F.X+O.Y H.X+P.Y
-        add                 v3.4S, v3.4S, v16.4S            // update val accumulator for part 1
-        add                 v4.4S, v4.4S, v17.4S            // update val accumulator for part 2
+        ld1r                {v7.8H}, [x10], #2              // read 1x16-bit coeff X at filter[j  ] and duplicate across lanes
+        ld1r                {v8.8H}, [x10], #2              // read 1x16-bit coeff Y at filter[j+1] and duplicate across lanes
+        smlal               v3.4S, v5.4H, v7.4H             // val0 += {A,B,C,D} * X
+        smlal2              v4.4S, v5.8H, v7.8H             // val1 += {E,F,G,H} * X
+        smlal               v3.4S, v6.4H, v8.4H             // val0 += {I,J,K,L} * Y
+        smlal2              v4.4S, v6.8H, v8.8H             // val1 += {M,N,O,P} * Y
         subs                w8, w8, #2                      // tmpfilterSize -= 2
         b.gt                3b                              // loop until filterSize consumed
-        sshr                v3.4S, v3.4S, #19               // val>>19 (part 1)
-        sshr                v4.4S, v4.4S, #19               // val>>19 (part 2)
-        sqxtun              v3.4H, v3.4S                    // clip16(val>>19) (part 1)
-        sqxtun              v4.4H, v4.4S                    // clip16(val>>19) (part 2)
-        mov                 v3.D[1], v4.D[0]                // merge part 1 and part 2
-        uqxtn               v3.8B, v3.8H                    // clip8(val>>19)
-        st1                 {v3.1D}, [x3], #8               // write to destination
-        add                 x7, x7, #8                      // i += 8
+
+        sqshrun             v3.4h, v3.4s, #16               // clip16(val0>>16)
+        sqshrun2            v3.8h, v4.4s, #16               // clip16(val1>>16)
+        uqshrn              v3.8b, v3.8h, #3                // clip8(val>>19)
+        st1                 {v3.8b}, [x3], #8               // write to destination
         subs                w4, w4, #8                      // dstW -= 8
+        add                 x7, x7, #8                      // i += 8
         b.gt                2b                              // loop until width consumed
         ret
 endfunc