--- /dev/null
+;
+; Copyright (c) 2013 The WebM project authors. All Rights Reserved.
+;
+; Use of this source code is governed by a BSD-style license
+; that can be found in the LICENSE file in the root of the source
+; tree. An additional intellectual property rights grant can be found
+; in the file PATENTS. All contributing project authors may
+; be found in the AUTHORS file in the root of the source tree.
+;
+
+;TODO(cd): adjust these constant to be able to use vqdmulh for faster
+; dct_const_round_shift(a * b) within butterfly calculations.
+cospi_1_64 EQU 16364
+cospi_2_64 EQU 16305
+cospi_3_64 EQU 16207
+cospi_4_64 EQU 16069
+cospi_5_64 EQU 15893
+cospi_6_64 EQU 15679
+cospi_7_64 EQU 15426
+cospi_8_64 EQU 15137
+cospi_9_64 EQU 14811
+cospi_10_64 EQU 14449
+cospi_11_64 EQU 14053
+cospi_12_64 EQU 13623
+cospi_13_64 EQU 13160
+cospi_14_64 EQU 12665
+cospi_15_64 EQU 12140
+cospi_16_64 EQU 11585
+cospi_17_64 EQU 11003
+cospi_18_64 EQU 10394
+cospi_19_64 EQU 9760
+cospi_20_64 EQU 9102
+cospi_21_64 EQU 8423
+cospi_22_64 EQU 7723
+cospi_23_64 EQU 7005
+cospi_24_64 EQU 6270
+cospi_25_64 EQU 5520
+cospi_26_64 EQU 4756
+cospi_27_64 EQU 3981
+cospi_28_64 EQU 3196
+cospi_29_64 EQU 2404
+cospi_30_64 EQU 1606
+cospi_31_64 EQU 804
+
+
+ EXPORT |idct32_transpose_and_transform|
+ EXPORT |idct32_combine_add|
+ ARM
+ REQUIRE8
+ PRESERVE8
+
+ AREA ||.text||, CODE, READONLY, ALIGN=2
+
+ AREA Block, CODE, READONLY
+
+ ; --------------------------------------------------------------------------
+ ; Load from transposed_buffer
+ ; q13 = transposed_buffer[first_offset]
+ ; q14 = transposed_buffer[second_offset]
+ ; for proper address calculation, the last offset used when manipulating
+ ; transposed_buffer must be passed in. use 0 for first use.
+ MACRO
+ LOAD_FROM_TRANSPOSED $prev_offset, $first_offset, $second_offset
+ ; address calculation with proper stride and loading
+ add r0, #($first_offset - $prev_offset )*8*2
+ vld1.s16 {q14}, [r0]
+ add r0, #($second_offset - $first_offset)*8*2
+ vld1.s16 {q13}, [r0]
+ ; (used) two registers (q14, q13)
+ MEND
+ ; --------------------------------------------------------------------------
+ ; Load from output (used as temporary storage)
+ ; reg1 = output[first_offset]
+ ; reg2 = output[second_offset]
+ ; for proper address calculation, the last offset used when manipulating
+ ; output, wethere reading or storing) must be passed in. use 0 for first
+ ; use.
+ MACRO
+ LOAD_FROM_OUTPUT $prev_offset, $first_offset, $second_offset, $reg1, $reg2
+ ; address calculation with proper stride and loading
+ add r1, #($first_offset - $prev_offset )*32*2
+ vld1.s16 {$reg1}, [r1]
+ add r1, #($second_offset - $first_offset)*32*2
+ vld1.s16 {$reg2}, [r1]
+ ; (used) two registers ($reg1, $reg2)
+ MEND
+ ; --------------------------------------------------------------------------
+ ; Store into output (sometimes as as temporary storage)
+ ; output[first_offset] = reg1
+ ; output[second_offset] = reg2
+ ; for proper address calculation, the last offset used when manipulating
+ ; output, wethere reading or storing) must be passed in. use 0 for first
+ ; use.
+ MACRO
+ STORE_IN_OUTPUT $prev_offset, $first_offset, $second_offset, $reg1, $reg2
+ ; address calculation with proper stride and storing
+ add r1, #($first_offset - $prev_offset )*32*2
+ vst1.16 {$reg1}, [r1]
+ add r1, #($second_offset - $first_offset)*32*2
+ vst1.16 {$reg2}, [r1]
+ MEND
+ ; --------------------------------------------------------------------------
+ ; Touches q8-q12, q15 (q13-q14 are preserved)
+ ; valid output registers are anything but q8-q11
+ MACRO
+ DO_BUTTERFLY $regC, $regD, $regA, $regB, $first_constant, $second_constant, $reg1, $reg2, $reg3, $reg4
+ ; TODO(cd): have special case to re-use constants when they are similar for
+ ; consecutive butterflies
+ ; TODO(cd): have special case when both constants are the same, do the
+ ; additions/substractions before the multiplies.
+ ; generate the constants
+ ; generate scalar constants
+ mov r3, #$first_constant & 0xFF00
+ add r3, #$first_constant & 0x00FF
+ mov r12, #$second_constant & 0xFF00
+ add r12, #$second_constant & 0x00FF
+ ; generate vector constants
+ vdup.16 d30, r3
+ vdup.16 d31, r12
+ ; (used) two for inputs (regA-regD), one for constants (q15)
+ ; do some multiplications (ordered for maximum latency hiding)
+ vmull.s16 q8, $regC, d30
+ vmull.s16 q10, $regA, d31
+ vmull.s16 q9, $regD, d30
+ vmull.s16 q11, $regB, d31
+ vmull.s16 q12, $regC, d31
+ ; (used) five for intermediate (q8-q12), one for constants (q15)
+ ; do some addition/substractions (to get back two register)
+ vsub.s32 q8, q8, q10
+ vsub.s32 q9, q9, q11
+ ; do more multiplications (ordered for maximum latency hiding)
+ vmull.s16 q10, $regD, d31
+ vmull.s16 q11, $regA, d30
+ vmull.s16 q15, $regB, d30
+ ; (used) six for intermediate (q8-q12, q15)
+ ; do more addition/substractions
+ vadd.s32 q11, q12, q11
+ vadd.s32 q10, q10, q15
+ ; (used) four for intermediate (q8-q11)
+ ; dct_const_round_shift
+ vqrshrn.s32 $reg1, q8, #14
+ vqrshrn.s32 $reg2, q9, #14
+ vqrshrn.s32 $reg3, q11, #14
+ vqrshrn.s32 $reg4, q10, #14
+ ; (used) two for results, well four d registers
+ MEND
+ ; --------------------------------------------------------------------------
+ ; Touches q8-q12, q15 (q13-q14 are preserved)
+ ; valid output registers are anything but q8-q11
+ MACRO
+ DO_BUTTERFLY_STD $first_constant, $second_constant, $reg1, $reg2, $reg3, $reg4
+ DO_BUTTERFLY d28, d29, d26, d27, $first_constant, $second_constant, $reg1, $reg2, $reg3, $reg4
+ MEND
+ ; --------------------------------------------------------------------------
+
+;void idct32_transpose_and_transform(int16_t *transpose_buffer, int16_t *output, int16_t *input);
+;
+; r0 int16_t *transpose_buffer
+; r1 int16_t *output
+; r2 int16_t *input)
+; TODO(cd): have more logical parameter ordering but this issue will disappear
+; when functions are combined.
+
+|idct32_transpose_and_transform| PROC
+ ; This function does one pass of idct32x32 transform.
+ ;
+ ; This is done by transposing the input and then doing a 1d transform on
+ ; columns. In the first pass, the transposed columns are the original
+ ; rows. In the second pass, after the transposition, the colums are the
+ ; original columns.
+ ; The 1d transform is done by looping over bands of eight columns (the
+ ; idct32_bands loop). For each band, the transform input transposition
+ ; is done on demand, one band of four 8x8 matrices at a time. The four
+ ; matrices are trsnposed by pairs (the idct32_transpose_pair loop).
+ push {r4}
+ mov r4, #0 ; initialize bands loop counter
+idct32_bands_loop
+ ; TODO(cd) get rid of these push/pop by properly adjusting register
+ ; content at end of loop
+ push {r0}
+ push {r1}
+ push {r2}
+ mov r3, #0 ; initialize transpose loop counter
+idct32_transpose_pair_loop
+ ; Load two horizontally consecutive 8x8 16bit data matrices. The first one
+ ; into q0-q7 and the second one into q8-q15. There is a stride of 64,
+ ; adjusted to 32 because of the two post-increments.
+ vld1.s16 {q8}, [r2]!
+ vld1.s16 {q0}, [r2]!
+ add r2, #32
+ vld1.s16 {q9}, [r2]!
+ vld1.s16 {q1}, [r2]!
+ add r2, #32
+ vld1.s16 {q10}, [r2]!
+ vld1.s16 {q2}, [r2]!
+ add r2, #32
+ vld1.s16 {q11}, [r2]!
+ vld1.s16 {q3}, [r2]!
+ add r2, #32
+ vld1.s16 {q12}, [r2]!
+ vld1.s16 {q4}, [r2]!
+ add r2, #32
+ vld1.s16 {q13}, [r2]!
+ vld1.s16 {q5}, [r2]!
+ add r2, #32
+ vld1.s16 {q14}, [r2]!
+ vld1.s16 {q6}, [r2]!
+ add r2, #32
+ vld1.s16 {q15}, [r2]!
+ vld1.s16 {q7}, [r2]!
+
+ ; Transpose the two 8x8 16bit data matrices.
+ vswp d17, d24
+ vswp d23, d30
+ vswp d21, d28
+ vswp d19, d26
+ vswp d1, d8
+ vswp d7, d14
+ vswp d5, d12
+ vswp d3, d10
+ vtrn.32 q8, q10
+ vtrn.32 q9, q11
+ vtrn.32 q12, q14
+ vtrn.32 q13, q15
+ vtrn.32 q0, q2
+ vtrn.32 q1, q3
+ vtrn.32 q4, q6
+ vtrn.32 q5, q7
+ vtrn.16 q8, q9
+ vtrn.16 q10, q11
+ vtrn.16 q12, q13
+ vtrn.16 q14, q15
+ vtrn.16 q0, q1
+ vtrn.16 q2, q3
+ vtrn.16 q4, q5
+ vtrn.16 q6, q7
+
+ ; Store both matrices after each other. There is a stride of 32, which
+ ; adjusts to nothing because of the post-increments.
+ vst1.16 {q8}, [r0]!
+ vst1.16 {q9}, [r0]!
+ vst1.16 {q10}, [r0]!
+ vst1.16 {q11}, [r0]!
+ vst1.16 {q12}, [r0]!
+ vst1.16 {q13}, [r0]!
+ vst1.16 {q14}, [r0]!
+ vst1.16 {q15}, [r0]!
+ vst1.16 {q0}, [r0]!
+ vst1.16 {q1}, [r0]!
+ vst1.16 {q2}, [r0]!
+ vst1.16 {q3}, [r0]!
+ vst1.16 {q4}, [r0]!
+ vst1.16 {q5}, [r0]!
+ vst1.16 {q6}, [r0]!
+ vst1.16 {q7}, [r0]!
+
+ ; increment pointers by adjusted stride (not necessary for r0/out)
+ sub r2, r2, #8*32*2-32-16*2
+ ; transpose pair loop processing
+ add r3, r3, #1
+ cmp r3, #1
+ BLE idct32_transpose_pair_loop
+
+ ; restore r0/input to its original value
+ sub r0, r0, #32*8*2
+
+ ; Instead of doing the transforms stage by stage, it is done by loading
+ ; some input values and doing as many stages as possible to minimize the
+ ; storing/loading of intermediate results. To fit within registers, the
+ ; final coefficients are cut into four blocks:
+ ; BLOCK A: 16-19,28-31
+ ; BLOCK B: 20-23,24-27
+ ; BLOCK C: 8-10,11-15
+ ; BLOCK D: 0-3,4-7
+ ; Blocks A and C are straight calculation through the various stages. In
+ ; block B, further calculations are performed using the results from
+ ; block A. In block D, further calculations are performed using the results
+ ; from block C and then the final calculations are done using results from
+ ; block A and B which have been combined at the end of block B.
+
+ ; --------------------------------------------------------------------------
+ ; BLOCK A: 16-19,28-31
+ ; --------------------------------------------------------------------------
+ ; generate 16,17,30,31
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[1 * 32] * cospi_31_64 - input[31 * 32] * cospi_1_64;
+ ;temp2 = input[1 * 32] * cospi_1_64 + input[31 * 32] * cospi_31_64;
+ ;step1b[16][i] = dct_const_round_shift(temp1);
+ ;step1b[31][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 0, 1, 31
+ DO_BUTTERFLY_STD cospi_31_64, cospi_1_64, d0, d1, d4, d5
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[17 * 32] * cospi_15_64 - input[15 * 32] * cospi_17_64;
+ ;temp2 = input[17 * 32] * cospi_17_64 + input[15 * 32] * cospi_15_64;
+ ;step1b[17][i] = dct_const_round_shift(temp1);
+ ;step1b[30][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 31, 17, 15
+ DO_BUTTERFLY_STD cospi_15_64, cospi_17_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;step2[16] = step1b[16][i] + step1b[17][i];
+ ;step2[17] = step1b[16][i] - step1b[17][i];
+ ;step2[30] = -step1b[30][i] + step1b[31][i];
+ ;step2[31] = step1b[30][i] + step1b[31][i];
+ vadd.s16 q4, q0, q1
+ vsub.s16 q13, q0, q1
+ vadd.s16 q6, q2, q3
+ vsub.s16 q14, q2, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;temp1 = step1b[30][i] * cospi_28_64 - step1b[17][i] * cospi_4_64;
+ ;temp2 = step1b[30][i] * cospi_4_64 - step1b[17][i] * cospi_28_64;
+ ;step3[17] = dct_const_round_shift(temp1);
+ ;step3[30] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_28_64, cospi_4_64, d10, d11, d14, d15
+ ; --------------------------------------------------------------------------
+ ; generate 18,19,28,29
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[9 * 32] * cospi_23_64 - input[23 * 32] * cospi_9_64;
+ ;temp2 = input[9 * 32] * cospi_9_64 + input[23 * 32] * cospi_23_64;
+ ;step1b[18][i] = dct_const_round_shift(temp1);
+ ;step1b[29][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 15, 9, 23
+ DO_BUTTERFLY_STD cospi_23_64, cospi_9_64, d0, d1, d4, d5
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[25 * 32] * cospi_7_64 - input[7 * 32] * cospi_25_64;
+ ;temp2 = input[25 * 32] * cospi_25_64 + input[7 * 32] * cospi_7_64;
+ ;step1b[19][i] = dct_const_round_shift(temp1);
+ ;step1b[28][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 23, 25, 7
+ DO_BUTTERFLY_STD cospi_7_64, cospi_25_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;step2[18] = -step1b[18][i] + step1b[19][i];
+ ;step2[19] = step1b[18][i] + step1b[19][i];
+ ;step2[28] = step1b[28][i] + step1b[29][i];
+ ;step2[29] = step1b[28][i] - step1b[29][i];
+ vsub.s16 q13, q3, q2
+ vadd.s16 q3, q3, q2
+ vsub.s16 q14, q1, q0
+ vadd.s16 q2, q1, q0
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;temp1 = step1b[18][i] * (-cospi_4_64) - step1b[29][i] * (-cospi_28_64);
+ ;temp2 = step1b[18][i] * (-cospi_28_64) + step1b[29][i] * (-cospi_4_64);
+ ;step3[29] = dct_const_round_shift(temp1);
+ ;step3[18] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD (-cospi_4_64), (-cospi_28_64), d2, d3, d0, d1
+ ; --------------------------------------------------------------------------
+ ; combine 16-19,28-31
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;step1[16] = step1b[16][i] + step1b[19][i];
+ ;step1[17] = step1b[17][i] + step1b[18][i];
+ ;step1[18] = step1b[17][i] - step1b[18][i];
+ ;step1[29] = step1b[30][i] - step1b[29][i];
+ ;step1[30] = step1b[30][i] + step1b[29][i];
+ ;step1[31] = step1b[31][i] + step1b[28][i];
+ vadd.s16 q8, q4, q2
+ vadd.s16 q9, q5, q0
+ vadd.s16 q10, q7, q1
+ vadd.s16 q15, q6, q3
+ vsub.s16 q13, q5, q0
+ vsub.s16 q14, q7, q1
+ STORE_IN_OUTPUT 0, 16, 31, q8, q15
+ STORE_IN_OUTPUT 31, 17, 30, q9, q10
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;temp1 = step1b[29][i] * cospi_24_64 - step1b[18][i] * cospi_8_64;
+ ;temp2 = step1b[29][i] * cospi_8_64 + step1b[18][i] * cospi_24_64;
+ ;step2[18] = dct_const_round_shift(temp1);
+ ;step2[29] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_24_64, cospi_8_64, d0, d1, d2, d3
+ STORE_IN_OUTPUT 30, 29, 18, q1, q0
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;step1[19] = step1b[16][i] - step1b[19][i];
+ ;step1[28] = step1b[31][i] - step1b[28][i];
+ vsub.s16 q13, q4, q2
+ vsub.s16 q14, q6, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;temp1 = step1b[28][i] * cospi_24_64 - step1b[19][i] * cospi_8_64;
+ ;temp2 = step1b[28][i] * cospi_8_64 + step1b[19][i] * cospi_24_64;
+ ;step2[19] = dct_const_round_shift(temp1);
+ ;step2[28] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_24_64, cospi_8_64, d8, d9, d12, d13
+ STORE_IN_OUTPUT 18, 19, 28, q4, q6
+ ; --------------------------------------------------------------------------
+
+
+ ; --------------------------------------------------------------------------
+ ; BLOCK B: 20-23,24-27
+ ; --------------------------------------------------------------------------
+ ; generate 20,21,26,27
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[5 * 32] * cospi_27_64 - input[27 * 32] * cospi_5_64;
+ ;temp2 = input[5 * 32] * cospi_5_64 + input[27 * 32] * cospi_27_64;
+ ;step1b[20][i] = dct_const_round_shift(temp1);
+ ;step1b[27][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 7, 5, 27
+ DO_BUTTERFLY_STD cospi_27_64, cospi_5_64, d0, d1, d4, d5
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[21 * 32] * cospi_11_64 - input[11 * 32] * cospi_21_64;
+ ;temp2 = input[21 * 32] * cospi_21_64 + input[11 * 32] * cospi_11_64;
+ ;step1b[21][i] = dct_const_round_shift(temp1);
+ ;step1b[26][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 27, 21, 11
+ DO_BUTTERFLY_STD cospi_11_64, cospi_21_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;step2[20] = step1b[20][i] + step1b[21][i];
+ ;step2[21] = step1b[20][i] - step1b[21][i];
+ ;step2[26] = -step1b[26][i] + step1b[27][i];
+ ;step2[27] = step1b[26][i] + step1b[27][i];
+ vsub.s16 q13, q0, q1
+ vadd.s16 q0, q0, q1
+ vsub.s16 q14, q2, q3
+ vadd.s16 q2, q2, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;temp1 = step1b[26][i] * cospi_12_64 - step1b[21][i] * cospi_20_64;
+ ;temp2 = step1b[26][i] * cospi_20_64 + step1b[21][i] * cospi_12_64;
+ ;step3[21] = dct_const_round_shift(temp1);
+ ;step3[26] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_12_64, cospi_20_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; generate 22,23,24,25
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[13 * 32] * cospi_19_64 - input[19 * 32] * cospi_13_64;
+ ;temp2 = input[13 * 32] * cospi_13_64 + input[19 * 32] * cospi_19_64;
+ ;step1b[22][i] = dct_const_round_shift(temp1);
+ ;step1b[25][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 11, 13, 19
+ DO_BUTTERFLY_STD cospi_19_64, cospi_13_64, d10, d11, d14, d15
+ ; --------------------------------------------------------------------------
+ ; part of stage 1
+ ;temp1 = input[29 * 32] * cospi_3_64 - input[3 * 32] * cospi_29_64;
+ ;temp2 = input[29 * 32] * cospi_29_64 + input[3 * 32] * cospi_3_64;
+ ;step1b[23][i] = dct_const_round_shift(temp1);
+ ;step1b[24][i] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 19, 29, 3
+ DO_BUTTERFLY_STD cospi_3_64, cospi_29_64, d8, d9, d12, d13
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;step2[22] = -step1b[22][i] + step1b[23][i];
+ ;step2[23] = step1b[22][i] + step1b[23][i];
+ ;step2[24] = step1b[24][i] + step1b[25][i];
+ ;step2[25] = step1b[24][i] - step1b[25][i];
+ vsub.s16 q14, q4, q5
+ vadd.s16 q5, q4, q5
+ vsub.s16 q13, q6, q7
+ vadd.s16 q6, q6, q7
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;temp1 = step1b[22][i] * (-cospi_20_64) - step1b[25][i] * (-cospi_12_64);
+ ;temp2 = step1b[22][i] * (-cospi_12_64) + step1b[25][i] * (-cospi_20_64);
+ ;step3[25] = dct_const_round_shift(temp1);
+ ;step3[22] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD (-cospi_20_64), (-cospi_12_64), d8, d9, d14, d15
+ ; --------------------------------------------------------------------------
+ ; combine 20-23,24-27
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;step1[22] = step1b[22][i] + step1b[21][i];
+ ;step1[23] = step1b[23][i] + step1b[20][i];
+ vadd.s16 q10, q7, q1
+ vadd.s16 q11, q5, q0
+ ;step1[24] = step1b[24][i] + step1b[27][i];
+ ;step1[25] = step1b[25][i] + step1b[26][i];
+ vadd.s16 q12, q6, q2
+ vadd.s16 q15, q4, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;step3[16] = step1b[16][i] + step1b[23][i];
+ ;step3[17] = step1b[17][i] + step1b[22][i];
+ ;step3[22] = step1b[17][i] - step1b[22][i];
+ ;step3[23] = step1b[16][i] - step1b[23][i];
+ LOAD_FROM_OUTPUT 28, 16, 17, q14, q13
+ vadd.s16 q8, q14, q11
+ vadd.s16 q9, q13, q10
+ vsub.s16 q13, q13, q10
+ vsub.s16 q11, q14, q11
+ STORE_IN_OUTPUT 17, 17, 16, q9, q8
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;step3[24] = step1b[31][i] - step1b[24][i];
+ ;step3[25] = step1b[30][i] - step1b[25][i];
+ ;step3[30] = step1b[30][i] + step1b[25][i];
+ ;step3[31] = step1b[31][i] + step1b[24][i];
+ LOAD_FROM_OUTPUT 16, 30, 31, q14, q9
+ vsub.s16 q8, q9, q12
+ vadd.s16 q10, q14, q15
+ vsub.s16 q14, q14, q15
+ vadd.s16 q12, q9, q12
+ STORE_IN_OUTPUT 31, 30, 31, q10, q12
+ ; --------------------------------------------------------------------------
+ ; TODO(cd) do some register allocation change to remove these push/pop
+ vpush {q8} ; [24]
+ vpush {q11} ; [23]
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;temp1 = (step1b[25][i] - step1b[22][i]) * cospi_16_64;
+ ;temp2 = (step1b[25][i] + step1b[22][i]) * cospi_16_64;
+ ;step1[22] = dct_const_round_shift(temp1);
+ ;step1[25] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d26, d27, d28, d29
+ STORE_IN_OUTPUT 31, 25, 22, q14, q13
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;temp1 = (step1b[24][i] - step1b[23][i]) * cospi_16_64;
+ ;temp2 = (step1b[24][i] + step1b[23][i]) * cospi_16_64;
+ ;step1[23] = dct_const_round_shift(temp1);
+ ;step1[24] = dct_const_round_shift(temp2);
+ ; TODO(cd) do some register allocation change to remove these push/pop
+ vpop {q13} ; [23]
+ vpop {q14} ; [24]
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d26, d27, d28, d29
+ STORE_IN_OUTPUT 22, 24, 23, q14, q13
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;step1[20] = step1b[23][i] - step1b[20][i];
+ ;step1[27] = step1b[24][i] - step1b[27][i];
+ vsub.s16 q14, q5, q0
+ vsub.s16 q13, q6, q2
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;temp1 = step1b[20][i] * (-cospi_8_64) - step1b[27][i] * (-cospi_24_64);
+ ;temp2 = step1b[20][i] * (-cospi_24_64) + step1b[27][i] * (-cospi_8_64);
+ ;step2[27] = dct_const_round_shift(temp1);
+ ;step2[20] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD (-cospi_8_64), (-cospi_24_64), d10, d11, d12, d13
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;step1[21] = step1b[22][i] - step1b[21][i];
+ ;step1[26] = step1b[25][i] - step1b[26][i];
+ vsub.s16 q14, q7, q1
+ vsub.s16 q13, q4, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;temp1 = step1b[21][i] * (-cospi_8_64) - step1b[26][i] * (-cospi_24_64);
+ ;temp2 = step1b[21][i] * (-cospi_24_64) + step1b[26][i] * (-cospi_8_64);
+ ;step2[26] = dct_const_round_shift(temp1);
+ ;step2[21] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD (-cospi_8_64), (-cospi_24_64), d0, d1, d2, d3
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;step3[18] = step1b[18][i] + step1b[21][i];
+ ;step3[19] = step1b[19][i] + step1b[20][i];
+ ;step3[20] = step1b[19][i] - step1b[20][i];
+ ;step3[21] = step1b[18][i] - step1b[21][i];
+ LOAD_FROM_OUTPUT 23, 18, 19, q14, q13
+ vadd.s16 q8, q14, q1
+ vadd.s16 q9, q13, q6
+ vsub.s16 q13, q13, q6
+ vsub.s16 q1, q14, q1
+ STORE_IN_OUTPUT 19, 18, 19, q8, q9
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;step3[27] = step1b[28][i] - step1b[27][i];
+ ;step3[28] = step1b[28][i] + step1b[27][i];
+ ;step3[29] = step1b[29][i] + step1b[26][i];
+ ;step3[26] = step1b[29][i] - step1b[26][i];
+ LOAD_FROM_OUTPUT 19, 28, 29, q8, q9
+ vsub.s16 q14, q8, q5
+ vadd.s16 q10, q8, q5
+ vadd.s16 q11, q9, q0
+ vsub.s16 q0, q9, q0
+ STORE_IN_OUTPUT 29, 28, 29, q10, q11
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;temp1 = (step1b[27][i] - step1b[20][i]) * cospi_16_64;
+ ;temp2 = (step1b[27][i] + step1b[20][i]) * cospi_16_64;
+ ;step1[20] = dct_const_round_shift(temp1);
+ ;step1[27] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d26, d27, d28, d29
+ STORE_IN_OUTPUT 29, 20, 27, q13, q14
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;temp1 = (step1b[26][i] - step1b[21][i]) * cospi_16_64;
+ ;temp2 = (step1b[26][i] + step1b[21][i]) * cospi_16_64;
+ ;step1[21] = dct_const_round_shift(temp1);
+ ;step1[26] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY d0, d1, d2, d3, cospi_16_64, cospi_16_64, d2, d3, d0, d1
+ STORE_IN_OUTPUT 27, 21, 26, q1, q0
+ ; --------------------------------------------------------------------------
+
+
+ ; --------------------------------------------------------------------------
+ ; BLOCK C: 8-10,11-15
+ ; --------------------------------------------------------------------------
+ ; generate 8,9,14,15
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;temp1 = input[2 * 32] * cospi_30_64 - input[30 * 32] * cospi_2_64;
+ ;temp2 = input[2 * 32] * cospi_2_64 + input[30 * 32] * cospi_30_64;
+ ;step2[8] = dct_const_round_shift(temp1);
+ ;step2[15] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 3, 2, 30
+ DO_BUTTERFLY_STD cospi_30_64, cospi_2_64, d0, d1, d4, d5
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;temp1 = input[18 * 32] * cospi_14_64 - input[14 * 32] * cospi_18_64;
+ ;temp2 = input[18 * 32] * cospi_18_64 + input[14 * 32] * cospi_14_64;
+ ;step2[9] = dct_const_round_shift(temp1);
+ ;step2[14] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 30, 18, 14
+ DO_BUTTERFLY_STD cospi_14_64, cospi_18_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;step3[8] = step1b[8][i] + step1b[9][i];
+ ;step3[9] = step1b[8][i] - step1b[9][i];
+ ;step3[14] = step1b[15][i] - step1b[14][i];
+ ;step3[15] = step1b[15][i] + step1b[14][i];
+ vsub.s16 q13, q0, q1
+ vadd.s16 q0, q0, q1
+ vsub.s16 q14, q2, q3
+ vadd.s16 q2, q2, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;temp1 = step1b[14][i] * cospi_24_64 - step1b[9][i] * cospi_8_64;
+ ;temp2 = step1b[14][i] * cospi_8_64 + step1b[9][i] * cospi_24_64;
+ ;step1[9] = dct_const_round_shift(temp1);
+ ;step1[14] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_24_64, cospi_8_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; generate 10,11,12,13
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;temp1 = input[10 * 32] * cospi_22_64 - input[22 * 32] * cospi_10_64;
+ ;temp2 = input[10 * 32] * cospi_10_64 + input[22 * 32] * cospi_22_64;
+ ;step2[10] = dct_const_round_shift(temp1);
+ ;step2[13] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 14, 10, 22
+ DO_BUTTERFLY_STD cospi_22_64, cospi_10_64, d10, d11, d14, d15
+ ; --------------------------------------------------------------------------
+ ; part of stage 2
+ ;temp1 = input[26 * 32] * cospi_6_64 - input[6 * 32] * cospi_26_64;
+ ;temp2 = input[26 * 32] * cospi_26_64 + input[6 * 32] * cospi_6_64;
+ ;step2[11] = dct_const_round_shift(temp1);
+ ;step2[12] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 22, 26, 6
+ DO_BUTTERFLY_STD cospi_6_64, cospi_26_64, d8, d9, d12, d13
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;step3[10] = step1b[11][i] - step1b[10][i];
+ ;step3[11] = step1b[11][i] + step1b[10][i];
+ ;step3[12] = step1b[12][i] + step1b[13][i];
+ ;step3[13] = step1b[12][i] - step1b[13][i];
+ vsub.s16 q14, q4, q5
+ vadd.s16 q5, q4, q5
+ vsub.s16 q13, q6, q7
+ vadd.s16 q6, q6, q7
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;temp1 = step1b[10][i] * (-cospi_8_64) - step1b[13][i] * (-cospi_24_64);
+ ;temp2 = step1b[10][i] * (-cospi_24_64) + step1b[13][i] * (-cospi_8_64);
+ ;step1[13] = dct_const_round_shift(temp1);
+ ;step1[10] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD (-cospi_8_64), (-cospi_24_64), d8, d9, d14, d15
+ ; --------------------------------------------------------------------------
+ ; combine 8-10,11-15
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;step2[8] = step1b[8][i] + step1b[11][i];
+ ;step2[9] = step1b[9][i] + step1b[10][i];
+ ;step2[10] = step1b[9][i] - step1b[10][i];
+ vadd.s16 q8, q0, q5
+ vadd.s16 q9, q1, q7
+ vsub.s16 q13, q1, q7
+ ;step2[13] = step1b[14][i] - step1b[13][i];
+ ;step2[14] = step1b[14][i] + step1b[13][i];
+ ;step2[15] = step1b[15][i] + step1b[12][i];
+ vsub.s16 q14, q3, q4
+ vadd.s16 q10, q3, q4
+ vadd.s16 q15, q2, q6
+ STORE_IN_OUTPUT 26, 8, 15, q8, q15
+ STORE_IN_OUTPUT 15, 9, 14, q9, q10
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;temp1 = (step1b[13][i] - step1b[10][i]) * cospi_16_64;
+ ;temp2 = (step1b[13][i] + step1b[10][i]) * cospi_16_64;
+ ;step3[10] = dct_const_round_shift(temp1);
+ ;step3[13] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d2, d3, d6, d7
+ STORE_IN_OUTPUT 14, 13, 10, q3, q1
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;step2[11] = step1b[8][i] - step1b[11][i];
+ ;step2[12] = step1b[15][i] - step1b[12][i];
+ vsub.s16 q13, q0, q5
+ vsub.s16 q14, q2, q6
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;temp1 = (step1b[12][i] - step1b[11][i]) * cospi_16_64;
+ ;temp2 = (step1b[12][i] + step1b[11][i]) * cospi_16_64;
+ ;step3[11] = dct_const_round_shift(temp1);
+ ;step3[12] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d2, d3, d6, d7
+ STORE_IN_OUTPUT 10, 11, 12, q1, q3
+ ; --------------------------------------------------------------------------
+
+
+ ; --------------------------------------------------------------------------
+ ; BLOCK D: 0-3,4-7
+ ; --------------------------------------------------------------------------
+ ; generate 4,5,6,7
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;temp1 = input[4 * 32] * cospi_28_64 - input[28 * 32] * cospi_4_64;
+ ;temp2 = input[4 * 32] * cospi_4_64 + input[28 * 32] * cospi_28_64;
+ ;step3[4] = dct_const_round_shift(temp1);
+ ;step3[7] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 6, 4, 28
+ DO_BUTTERFLY_STD cospi_28_64, cospi_4_64, d0, d1, d4, d5
+ ; --------------------------------------------------------------------------
+ ; part of stage 3
+ ;temp1 = input[20 * 32] * cospi_12_64 - input[12 * 32] * cospi_20_64;
+ ;temp2 = input[20 * 32] * cospi_20_64 + input[12 * 32] * cospi_12_64;
+ ;step3[5] = dct_const_round_shift(temp1);
+ ;step3[6] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 28, 20, 12
+ DO_BUTTERFLY_STD cospi_12_64, cospi_20_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;step1[4] = step1b[4][i] + step1b[5][i];
+ ;step1[5] = step1b[4][i] - step1b[5][i];
+ ;step1[6] = step1b[7][i] - step1b[6][i];
+ ;step1[7] = step1b[7][i] + step1b[6][i];
+ vsub.s16 q13, q0, q1
+ vadd.s16 q0, q0, q1
+ vsub.s16 q14, q2, q3
+ vadd.s16 q2, q2, q3
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;temp1 = (step1b[6][i] - step1b[5][i]) * cospi_16_64;
+ ;temp2 = (step1b[5][i] + step1b[6][i]) * cospi_16_64;
+ ;step2[5] = dct_const_round_shift(temp1);
+ ;step2[6] = dct_const_round_shift(temp2);
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d2, d3, d6, d7
+ ; --------------------------------------------------------------------------
+ ; generate 0,1,2,3
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;temp1 = (input[0 * 32] - input[16 * 32]) * cospi_16_64;
+ ;temp2 = (input[0 * 32] + input[16 * 32]) * cospi_16_64;
+ ;step1[1] = dct_const_round_shift(temp1);
+ ;step1[0] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 12, 0, 16
+ DO_BUTTERFLY_STD cospi_16_64, cospi_16_64, d10, d11, d14, d15
+ ; --------------------------------------------------------------------------
+ ; part of stage 4
+ ;temp1 = input[8 * 32] * cospi_24_64 - input[24 * 32] * cospi_8_64;
+ ;temp2 = input[8 * 32] * cospi_8_64 + input[24 * 32] * cospi_24_64;
+ ;step1[2] = dct_const_round_shift(temp1);
+ ;step1[3] = dct_const_round_shift(temp2);
+ LOAD_FROM_TRANSPOSED 16, 8, 24
+ DO_BUTTERFLY_STD cospi_24_64, cospi_8_64, d28, d29, d12, d13
+ ; --------------------------------------------------------------------------
+ ; part of stage 5
+ ;step2[0] = step1b[0][i] + step1b[3][i];
+ ;step2[1] = step1b[1][i] + step1b[2][i];
+ ;step2[2] = step1b[1][i] - step1b[2][i];
+ ;step2[3] = step1b[0][i] - step1b[3][i];
+ vadd.s16 q4, q7, q6
+ vsub.s16 q7, q7, q6
+ vsub.s16 q6, q5, q14
+ vadd.s16 q5, q5, q14
+ ; --------------------------------------------------------------------------
+ ; combine 0-3,4-7
+ ; --------------------------------------------------------------------------
+ ; part of stage 6
+ ;step3[0] = step1b[0][i] + step1b[7][i];
+ ;step3[1] = step1b[1][i] + step1b[6][i];
+ ;step3[2] = step1b[2][i] + step1b[5][i];
+ ;step3[3] = step1b[3][i] + step1b[4][i];
+ vadd.s16 q8, q4, q2
+ vadd.s16 q9, q5, q3
+ vadd.s16 q10, q6, q1
+ vadd.s16 q11, q7, q0
+ ;step3[4] = step1b[3][i] - step1b[4][i];
+ ;step3[5] = step1b[2][i] - step1b[5][i];
+ ;step3[6] = step1b[1][i] - step1b[6][i];
+ ;step3[7] = step1b[0][i] - step1b[7][i];
+ vsub.s16 q12, q7, q0
+ vsub.s16 q13, q6, q1
+ vsub.s16 q14, q5, q3
+ vsub.s16 q15, q4, q2
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;step1[0] = step1b[0][i] + step1b[15][i];
+ ;step1[1] = step1b[1][i] + step1b[14][i];
+ ;step1[14] = step1b[1][i] - step1b[14][i];
+ ;step1[15] = step1b[0][i] - step1b[15][i];
+ LOAD_FROM_OUTPUT 12, 14, 15, q0, q1
+ vadd.s16 q2, q8, q1
+ vadd.s16 q3, q9, q0
+ vsub.s16 q4, q9, q0
+ vsub.s16 q5, q8, q1
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[14 * 32] = step1b[14][i] + step1b[17][i];
+ ;output[15 * 32] = step1b[15][i] + step1b[16][i];
+ ;output[16 * 32] = step1b[15][i] - step1b[16][i];
+ ;output[17 * 32] = step1b[14][i] - step1b[17][i];
+ LOAD_FROM_OUTPUT 15, 16, 17, q0, q1
+ vadd.s16 q8, q4, q1
+ vadd.s16 q9, q5, q0
+ vsub.s16 q6, q5, q0
+ vsub.s16 q7, q4, q1
+ STORE_IN_OUTPUT 17, 17, 16, q7, q6
+ STORE_IN_OUTPUT 16, 15, 14, q9, q8
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[ 0 * 32] = step1b[0][i] + step1b[31][i];
+ ;output[ 1 * 32] = step1b[1][i] + step1b[30][i];
+ ;output[30 * 32] = step1b[1][i] - step1b[30][i];
+ ;output[31 * 32] = step1b[0][i] - step1b[31][i];
+ LOAD_FROM_OUTPUT 14, 30, 31, q0, q1
+ vadd.s16 q4, q2, q1
+ vadd.s16 q5, q3, q0
+ vsub.s16 q6, q3, q0
+ vsub.s16 q7, q2, q1
+ STORE_IN_OUTPUT 31, 31, 30, q7, q6
+ STORE_IN_OUTPUT 30, 0, 1, q4, q5
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;step1[2] = step1b[2][i] + step1b[13][i];
+ ;step1[3] = step1b[3][i] + step1b[12][i];
+ ;step1[12] = step1b[3][i] - step1b[12][i];
+ ;step1[13] = step1b[2][i] - step1b[13][i];
+ LOAD_FROM_OUTPUT 1, 12, 13, q0, q1
+ vadd.s16 q2, q10, q1
+ vadd.s16 q3, q11, q0
+ vsub.s16 q4, q11, q0
+ vsub.s16 q5, q10, q1
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[12 * 32] = step1b[12][i] + step1b[19][i];
+ ;output[13 * 32] = step1b[13][i] + step1b[18][i];
+ ;output[18 * 32] = step1b[13][i] - step1b[18][i];
+ ;output[19 * 32] = step1b[12][i] - step1b[19][i];
+ LOAD_FROM_OUTPUT 13, 18, 19, q0, q1
+ vadd.s16 q6, q4, q1
+ vadd.s16 q7, q5, q0
+ vsub.s16 q8, q5, q0
+ vsub.s16 q9, q4, q1
+ STORE_IN_OUTPUT 19, 19, 18, q9, q8
+ STORE_IN_OUTPUT 18, 13, 12, q7, q6
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[ 2 * 32] = step1b[2][i] + step1b[29][i];
+ ;output[ 3 * 32] = step1b[3][i] + step1b[28][i];
+ ;output[28 * 32] = step1b[3][i] - step1b[28][i];
+ ;output[29 * 32] = step1b[2][i] - step1b[29][i];
+ LOAD_FROM_OUTPUT 12, 28, 29, q0, q1
+ vadd.s16 q4, q2, q1
+ vadd.s16 q5, q3, q0
+ vsub.s16 q6, q3, q0
+ vsub.s16 q7, q2, q1
+ STORE_IN_OUTPUT 29, 29, 28, q7, q6
+ STORE_IN_OUTPUT 28, 2, 3, q4, q5
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;step1[4] = step1b[4][i] + step1b[11][i];
+ ;step1[5] = step1b[5][i] + step1b[10][i];
+ ;step1[10] = step1b[5][i] - step1b[10][i];
+ ;step1[11] = step1b[4][i] - step1b[11][i];
+ LOAD_FROM_OUTPUT 3, 10, 11, q0, q1
+ vadd.s16 q2, q12, q1
+ vadd.s16 q3, q13, q0
+ vsub.s16 q4, q13, q0
+ vsub.s16 q5, q12, q1
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[10 * 32] = step1b[10][i] + step1b[21][i];
+ ;output[11 * 32] = step1b[11][i] + step1b[20][i];
+ ;output[20 * 32] = step1b[11][i] - step1b[20][i];
+ ;output[21 * 32] = step1b[10][i] - step1b[21][i];
+ LOAD_FROM_OUTPUT 11, 20, 21, q0, q1
+ vadd.s16 q6, q4, q1
+ vadd.s16 q7, q5, q0
+ vsub.s16 q8, q5, q0
+ vsub.s16 q9, q4, q1
+ STORE_IN_OUTPUT 21, 21, 20, q9, q8
+ STORE_IN_OUTPUT 20, 11, 10, q7, q6
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[ 4 * 32] = step1b[4][i] + step1b[27][i];
+ ;output[ 5 * 32] = step1b[5][i] + step1b[26][i];
+ ;output[26 * 32] = step1b[5][i] - step1b[26][i];
+ ;output[27 * 32] = step1b[4][i] - step1b[27][i];
+ LOAD_FROM_OUTPUT 10, 26, 27, q0, q1
+ vadd.s16 q4, q2, q1
+ vadd.s16 q5, q3, q0
+ vsub.s16 q6, q3, q0
+ vsub.s16 q7, q2, q1
+ STORE_IN_OUTPUT 27, 27, 26, q7, q6
+ STORE_IN_OUTPUT 26, 4, 5, q4, q5
+ ; --------------------------------------------------------------------------
+ ; part of stage 7
+ ;step1[6] = step1b[6][i] + step1b[9][i];
+ ;step1[7] = step1b[7][i] + step1b[8][i];
+ ;step1[8] = step1b[7][i] - step1b[8][i];
+ ;step1[9] = step1b[6][i] - step1b[9][i];
+ LOAD_FROM_OUTPUT 5, 8, 9, q0, q1
+ vadd.s16 q2, q14, q1
+ vadd.s16 q3, q15, q0
+ vsub.s16 q4, q15, q0
+ vsub.s16 q5, q14, q1
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[ 8 * 32] = step1b[8][i] + step1b[23][i];
+ ;output[ 9 * 32] = step1b[9][i] + step1b[22][i];
+ ;output[22 * 32] = step1b[9][i] - step1b[22][i];
+ ;output[23 * 32] = step1b[8][i] - step1b[23][i];
+ LOAD_FROM_OUTPUT 9, 22, 23, q0, q1
+ vadd.s16 q6, q4, q1
+ vadd.s16 q7, q5, q0
+ vsub.s16 q8, q5, q0
+ vsub.s16 q9, q4, q1
+ STORE_IN_OUTPUT 23, 23, 22, q9, q8
+ STORE_IN_OUTPUT 22, 9, 8, q7, q6
+ ; --------------------------------------------------------------------------
+ ; part of final stage
+ ;output[ 6 * 32] = step1b[6][i] + step1b[25][i];
+ ;output[ 7 * 32] = step1b[7][i] + step1b[24][i];
+ ;output[24 * 32] = step1b[7][i] - step1b[24][i];
+ ;output[25 * 32] = step1b[6][i] - step1b[25][i];
+ LOAD_FROM_OUTPUT 8, 24, 25, q0, q1
+ vadd.s16 q4, q2, q1
+ vadd.s16 q5, q3, q0
+ vsub.s16 q6, q3, q0
+ vsub.s16 q7, q2, q1
+ STORE_IN_OUTPUT 25, 25, 24, q7, q6
+ STORE_IN_OUTPUT 24, 6, 7, q4, q5
+ ; --------------------------------------------------------------------------
+
+ ; TODO(cd) get rid of these push/pop by properly adjusting register
+ ; content at end of loop
+ pop {r2}
+ pop {r1}
+ pop {r0}
+ add r1, r1, #8*2
+ add r2, r2, #8*32*2
+
+ ; bands loop processing
+ add r4, r4, #1
+ cmp r4, #3
+ BLE idct32_bands_loop
+
+ pop {r4}
+ bx lr
+ ENDP ; |idct32_transpose_and_transform|
+
+;void idct32_combine_add(uint8_t *dest, int16_t *out, int dest_stride);
+;
+; r0 uint8_t *dest
+; r1 int16_t *out
+; r2 int dest_stride)
+
+|idct32_combine_add| PROC
+
+ mov r12, r0 ; dest pointer used for stores
+ sub r2, r2, #32 ; adjust the stride (remove the post-increments)
+ mov r3, #0 ; initialize loop counter
+
+idct32_combine_add_loop
+ ; load out[j * 32 + 0-31]
+ vld1.s16 {q12}, [r1]!
+ vld1.s16 {q13}, [r1]!
+ vld1.s16 {q14}, [r1]!
+ vld1.s16 {q15}, [r1]!
+ ; load dest[j * dest_stride + 0-31]
+ vld1.s16 {q6}, [r0]!
+ vld1.s16 {q7}, [r0]!
+ ; ROUND_POWER_OF_TWO
+ vrshr.s16 q12, q12, #6
+ vrshr.s16 q13, q13, #6
+ vrshr.s16 q14, q14, #6
+ vrshr.s16 q15, q15, #6
+ ; add to dest[j * dest_stride + 0-31]
+ vaddw.u8 q12, q12, d12
+ vaddw.u8 q13, q13, d13
+ vaddw.u8 q14, q14, d14
+ vaddw.u8 q15, q15, d15
+ ; clip pixel
+ vqmovun.s16 d12, q12
+ vqmovun.s16 d13, q13
+ vqmovun.s16 d14, q14
+ vqmovun.s16 d15, q15
+ ; store back into dest[j * dest_stride + 0-31]
+ vst1.16 {q6}, [r12]!
+ vst1.16 {q7}, [r12]!
+ ; increment pointers by adjusted stride (not necessary for r1/out)
+ add r0, r0, r2
+ add r12, r12, r2
+ ; loop processing
+ add r3, r3, #1
+ cmp r3, #31
+ BLE idct32_combine_add_loop
+
+ bx lr
+ ENDP ; |idct32_transpose|
+
+ END