diff options
| author | Martin Storsjö <martin@martin.st> | 2016-11-18 11:37:16 +0200 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2016-11-30 23:54:07 +0200 |
| commit | 9c8bc74c2b40537b0997f646c87c008042d788c2 (patch) | |
| tree | 23a844fd1e8017e66143ae96345379db71c648d9 /libavcodec | |
| parent | 3c87039a404c5659ae9bf7454a04e186532eb40b (diff) | |
arm: 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:
Cortex A7 A8 A9 A53
vp9_inv_dct_dct_16x16_sub16_add_neon: 3188.1 2435.4 2499.0 1969.0
vp9_inv_dct_dct_32x32_sub32_add_neon: 18531.7 16582.3 14207.6 12000.3
By skipping individual 4x16 or 4x32 pixel slices in the first pass,
we reduce the runtime of these functions like this:
vp9_inv_dct_dct_16x16_sub1_add_neon: 274.6 189.5 211.7 235.8
vp9_inv_dct_dct_16x16_sub2_add_neon: 2064.0 1534.8 1719.4 1248.7
vp9_inv_dct_dct_16x16_sub4_add_neon: 2135.0 1477.2 1736.3 1249.5
vp9_inv_dct_dct_16x16_sub8_add_neon: 2446.7 1828.7 1993.6 1494.7
vp9_inv_dct_dct_16x16_sub12_add_neon: 2832.4 2118.3 2266.5 1735.1
vp9_inv_dct_dct_16x16_sub16_add_neon: 3211.7 2475.3 2523.5 1983.1
vp9_inv_dct_dct_32x32_sub1_add_neon: 756.2 456.7 862.0 553.9
vp9_inv_dct_dct_32x32_sub2_add_neon: 10682.2 8190.4 8539.2 6762.5
vp9_inv_dct_dct_32x32_sub4_add_neon: 10813.5 8014.9 8518.3 6762.8
vp9_inv_dct_dct_32x32_sub8_add_neon: 11859.6 9313.0 9347.4 7514.5
vp9_inv_dct_dct_32x32_sub12_add_neon: 12946.6 10752.4 10192.2 8280.2
vp9_inv_dct_dct_32x32_sub16_add_neon: 14074.6 11946.5 11001.4 9008.6
vp9_inv_dct_dct_32x32_sub20_add_neon: 15269.9 13662.7 11816.1 9762.6
vp9_inv_dct_dct_32x32_sub24_add_neon: 16327.9 14940.1 12626.7 10516.0
vp9_inv_dct_dct_32x32_sub28_add_neon: 17462.7 15776.1 13446.2 11264.7
vp9_inv_dct_dct_32x32_sub32_add_neon: 18575.5 17157.0 14249.3 12015.1
I.e. in general a very minor overhead for the full subpartition case due
to the additional loads and cmps, but a significant speedup for the cases
when we only need to process a small part of the actual input data.
In common VP9 content in a few inspected clips, 70-90% of the non-dc-only
16x16 and 32x32 IDCTs only have nonzero coefficients in the upper left
8x8 or 16x16 subpartitions respectively.
Signed-off-by: Martin Storsjö <martin@martin.st>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/arm/vp9itxfm_neon.S | 75 |
1 files changed, 66 insertions, 9 deletions
diff --git a/libavcodec/arm/vp9itxfm_neon.S b/libavcodec/arm/vp9itxfm_neon.S index 2049241d08..5abe435be9 100644 --- a/libavcodec/arm/vp9itxfm_neon.S +++ b/libavcodec/arm/vp9itxfm_neon.S @@ -659,9 +659,8 @@ endfunc @ Read a vertical 4x16 slice out of a 16x16 matrix, do a transform on it, @ transpose into a horizontal 16x4 slice and store. @ r0 = dst (temp buffer) -@ r1 = unused +@ r1 = slice offset @ r2 = src -@ r3 = slice offset function \txfm\()16_1d_4x16_pass1_neon mov r12, #32 vmov.s16 q2, #0 @@ -678,14 +677,14 @@ function \txfm\()16_1d_4x16_pass1_neon transpose16_q_4x_4x4 q8, q9, q10, q11, q12, q13, q14, q15, d16, d17, d18, d19, d20, d21, d22, d23, d24, d25, d26, d27, d28, d29, d30, d31 @ Store the transposed 4x4 blocks horizontally. - cmp r3, #12 + cmp r1, #12 beq 1f .irp i, 16, 20, 24, 28, 17, 21, 25, 29, 18, 22, 26, 30, 19, 23, 27, 31 vst1.16 {d\i}, [r0,:64]! .endr bx lr 1: - @ Special case: For the last input column (r3 == 12), + @ Special case: For the last input column (r1 == 12), @ which would be stored as the last row in the temp buffer, @ don't store the first 4x4 block, but keep it in registers @ for the first slice of the second pass (where it is the @@ -781,15 +780,22 @@ endfunc itxfm16_1d_funcs idct itxfm16_1d_funcs iadst +@ This is the minimum eob value for each subpartition, in increments of 4 +const min_eob_idct_idct_16, align=4 + .short 0, 10, 38, 89 +endconst + .macro itxfm_func16x16 txfm1, txfm2 function ff_vp9_\txfm1\()_\txfm2\()_16x16_add_neon, export=1 .ifc \txfm1\()_\txfm2,idct_idct cmp r3, #1 beq idct16x16_dc_add_neon .endif - push {r4-r7,lr} + push {r4-r8,lr} .ifnc \txfm1\()_\txfm2,idct_idct vpush {q4-q7} +.else + movrel r8, min_eob_idct_idct_16 + 2 .endif @ Align the stack, allocate a temp buffer @@ -810,10 +816,36 @@ A and r7, sp, #15 .irp i, 0, 4, 8, 12 add r0, sp, #(\i*32) +.ifc \txfm1\()_\txfm2,idct_idct +.if \i > 0 + ldrh_post r1, r8, #2 + cmp r3, r1 + it le + movle r1, #(16 - \i)/4 + ble 1f +.endif +.endif + mov r1, #\i add r2, r6, #(\i*2) - mov r3, #\i bl \txfm1\()16_1d_4x16_pass1_neon .endr + +.ifc \txfm1\()_\txfm2,idct_idct + b 3f +1: + @ For all-zero slices in pass 1, set d28-d31 to zero, for the in-register + @ passthrough of coefficients to pass 2 and clear the end of the temp buffer + vmov.i16 q14, #0 + vmov.i16 q15, #0 +2: + subs r1, r1, #1 +.rept 4 + vst1.16 {q14-q15}, [r0,:128]! +.endr + bne 2b +3: +.endif + .ifc \txfm1\()_\txfm2,iadst_idct movrel r12, idct_coeffs vld1.16 {q0-q1}, [r12,:128] @@ -830,7 +862,7 @@ A and r7, sp, #15 .ifnc \txfm1\()_\txfm2,idct_idct vpop {q4-q7} .endif - pop {r4-r7,pc} + pop {r4-r8,pc} endfunc .endm @@ -1110,11 +1142,16 @@ function idct32_1d_4x32_pass2_neon bx lr endfunc +const min_eob_idct_idct_32, align=4 + .short 0, 9, 34, 70, 135, 240, 336, 448 +endconst + function ff_vp9_idct_idct_32x32_add_neon, export=1 cmp r3, #1 beq idct32x32_dc_add_neon - push {r4-r7,lr} + push {r4-r8,lr} vpush {q4-q7} + movrel r8, min_eob_idct_idct_32 + 2 @ Align the stack, allocate a temp buffer T mov r7, sp @@ -1129,9 +1166,29 @@ A and r7, sp, #15 .irp i, 0, 4, 8, 12, 16, 20, 24, 28 add r0, sp, #(\i*64) +.if \i > 0 + ldrh_post r1, r8, #2 + cmp r3, r1 + it le + movle r1, #(32 - \i)/2 + ble 1f +.endif add r2, r6, #(\i*2) bl idct32_1d_4x32_pass1_neon .endr + b 3f + +1: + @ Write zeros to the temp buffer for pass 2 + vmov.i16 q14, #0 + vmov.i16 q15, #0 +2: + subs r1, r1, #1 +.rept 4 + vst1.16 {q14-q15}, [r0,:128]! +.endr + bne 2b +3: .irp i, 0, 4, 8, 12, 16, 20, 24, 28 add r0, r4, #(\i) mov r1, r5 @@ -1141,5 +1198,5 @@ A and r7, sp, #15 add sp, sp, r7 vpop {q4-q7} - pop {r4-r7,pc} + pop {r4-r8,pc} endfunc |