From 8b11a89c06b94632d545f67ca508bd9c05c435ac Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Tue, 10 Jan 2017 00:15:16 +0200 Subject: [PATCH] aarch64: vp9itxfm: Skip empty slices in the first pass of idct_idct 16x16 and 32x32 This work is sponsored by, and copyright, Google. Previously all subpartitions except the eob=1 (DC) case ran with the same runtime: vp9_inv_dct_dct_16x16_sub16_add_neon: 1373.2 vp9_inv_dct_dct_32x32_sub32_add_neon: 8089.0 By skipping individual 8x16 or 8x32 pixel slices in the first pass, we reduce the runtime of these functions like this: vp9_inv_dct_dct_16x16_sub1_add_neon: 235.3 vp9_inv_dct_dct_16x16_sub2_add_neon: 1036.7 vp9_inv_dct_dct_16x16_sub4_add_neon: 1036.7 vp9_inv_dct_dct_16x16_sub8_add_neon: 1036.7 vp9_inv_dct_dct_16x16_sub12_add_neon: 1372.1 vp9_inv_dct_dct_16x16_sub16_add_neon: 1372.1 vp9_inv_dct_dct_32x32_sub1_add_neon: 555.1 vp9_inv_dct_dct_32x32_sub2_add_neon: 5190.2 vp9_inv_dct_dct_32x32_sub4_add_neon: 5180.0 vp9_inv_dct_dct_32x32_sub8_add_neon: 5183.1 vp9_inv_dct_dct_32x32_sub12_add_neon: 6161.5 vp9_inv_dct_dct_32x32_sub16_add_neon: 6155.5 vp9_inv_dct_dct_32x32_sub20_add_neon: 7136.3 vp9_inv_dct_dct_32x32_sub24_add_neon: 7128.4 vp9_inv_dct_dct_32x32_sub28_add_neon: 8098.9 vp9_inv_dct_dct_32x32_sub32_add_neon: 8098.8 I.e. in general a very minor overhead for the full subpartition case due to the additional cmps, but a significant speedup for the cases when we only need to process a small part of the actual input data. This is cherrypicked from libav commits cad42fadcd2c2ae1b3676bb398844a1f521a2d7b and a0c443a3980dc22eb02b067ac4cb9ffa2f9b04d2. Signed-off-by: Michael Niedermayer --- libavcodec/aarch64/vp9itxfm_neon.S | 61 +++++++++++++++++++++++++++--- 1 file changed, 56 insertions(+), 5 deletions(-) diff --git a/libavcodec/aarch64/vp9itxfm_neon.S b/libavcodec/aarch64/vp9itxfm_neon.S index e5fc6129c9..82f1f41579 100644 --- a/libavcodec/aarch64/vp9itxfm_neon.S +++ b/libavcodec/aarch64/vp9itxfm_neon.S @@ -588,6 +588,9 @@ endfunc .macro store i, dst, inc st1 {v\i\().8h}, [\dst], \inc .endm +.macro movi_v i, size, imm + movi v\i\()\size, \imm +.endm .macro load_clear i, src, inc ld1 {v\i\().8h}, [\src] st1 {v2.8h}, [\src], \inc @@ -596,9 +599,8 @@ endfunc // Read a vertical 8x16 slice out of a 16x16 matrix, do a transform on it, // transpose into a horizontal 16x8 slice and store. // x0 = dst (temp buffer) -// x1 = unused +// x1 = slice offset // x2 = src -// x3 = slice offset // x9 = input stride .macro itxfm16_1d_funcs txfm function \txfm\()16_1d_8x16_pass1_neon @@ -616,14 +618,14 @@ function \txfm\()16_1d_8x16_pass1_neon transpose_8x8H v24, v25, v26, v27, v28, v29, v30, v31, v2, v3 // Store the transposed 8x8 blocks horizontally. - cmp x3, #8 + cmp x1, #8 b.eq 1f .irp i, 16, 24, 17, 25, 18, 26, 19, 27, 20, 28, 21, 29, 22, 30, 23, 31 store \i, x0, #16 .endr ret 1: - // Special case: For the last input column (x3 == 8), + // Special case: For the last input column (x1 == 8), // which would be stored as the last row in the temp buffer, // don't store the first 8x8 block, but keep it in registers // for the first slice of the second pass (where it is the @@ -751,13 +753,36 @@ function ff_vp9_\txfm1\()_\txfm2\()_16x16_add_neon, export=1 .irp i, 0, 8 add x0, sp, #(\i*32) +.ifc \txfm1\()_\txfm2,idct_idct +.if \i == 8 + cmp w3, #38 + b.le 1f +.endif +.endif + mov x1, #\i add x2, x6, #(\i*2) - mov x3, #\i bl \txfm1\()16_1d_8x16_pass1_neon .endr .ifc \txfm1\()_\txfm2,iadst_idct ld1 {v0.8h,v1.8h}, [x10] .endif + +.ifc \txfm1\()_\txfm2,idct_idct + b 3f +1: + // Set v24-v31 to zero, for the in-register passthrough of + // coefficients to pass 2. Since we only do two slices, this can + // only ever happen for the second slice. So we only need to store + // zeros to the temp buffer for the second half of the buffer. + // Move x0 to the second half, and use x9 == 32 as increment. + add x0, x0, #16 +.irp i, 24, 25, 26, 27, 28, 29, 30, 31 + movi_v \i, .16b, #0 + st1 {v24.8h}, [x0], x9 +.endr +3: +.endif + .irp i, 0, 8 add x0, x4, #(\i) mov x1, x5 @@ -1073,12 +1098,17 @@ function idct32_1d_8x32_pass2_neon ret endfunc +const min_eob_idct_idct_32, align=4 + .short 0, 34, 135, 336 +endconst + function ff_vp9_idct_idct_32x32_add_neon, export=1 cmp w3, #1 b.eq idct32x32_dc_add_neon movrel x10, idct_coeffs add x11, x10, #32 + movrel x12, min_eob_idct_idct_32, 2 mov x15, x30 @@ -1099,9 +1129,30 @@ function ff_vp9_idct_idct_32x32_add_neon, export=1 .irp i, 0, 8, 16, 24 add x0, sp, #(\i*64) +.if \i > 0 + ldrh w1, [x12], #2 + cmp w3, w1 + mov x1, #(32 - \i)/4 + b.le 1f +.endif add x2, x6, #(\i*2) bl idct32_1d_8x32_pass1_neon .endr + b 3f + +1: + // Write zeros to the temp buffer for pass 2 + movi v16.8h, #0 + movi v17.8h, #0 + movi v18.8h, #0 + movi v19.8h, #0 +2: + subs x1, x1, #1 +.rept 4 + st1 {v16.8h-v19.8h}, [x0], #64 +.endr + b.ne 2b +3: .irp i, 0, 8, 16, 24 add x0, x4, #(\i) mov x1, x5