1 /***************************************************************************
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
10 * Copyright (C) 2009 by Jens Arnold
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
20 ****************************************************************************/
23 .global mpeg2_idct_copy
24 .type mpeg2_idct_copy, %function
25 .global mpeg2_idct_add
26 .type mpeg2_idct_add, %function
28 /* Custom calling convention:
29 * r0 contains block pointer and is non-volatile
30 * all non-volatile c context saved and restored on its behalf
33 str lr, [sp, #-4]! @ lr is used
34 add r1, r0, #128 @ secondary, transposed temp buffer
35 mov r14, #8 @ loop counter
38 ldmia r0!, {r2, r3, r10, r11} @ fetch f0, f2, f4, f6, f1, f3, f5, f7
39 ldrd r4, L_W1357 @ load W1, W3, W5, W7
41 smuad r6, r4, r10 @ b0 = W1 * f1 + W3 * f3
42 smlad r6, r5, r11, r6 @ + W5 * f5 + W7 * f7
44 smultt r7, r5, r10 @ b1 = -W7 * f3
45 smlabb r7, r4, r11, r7 @ + -W1 * f5
46 smlabt r7, r5, r11, r7 @ + -W5 * f7
48 smlatb r7, r4, r10, r7 @ + W3 * f1
50 smulbt r8, r4, r10 @ b2 = -W1 * f3
52 smlabb r8, r5, r10, r8 @ + W5 * f1
53 smlatb r8, r5, r11, r8 @ + W7 * f5
54 smlatt r8, r4, r11, r8 @ + W3 * f7
56 smusdx r9, r10, r5 @ b3 = f1 * W7 - f3 * W5
57 smlsdx r9, r11, r4, r9 @ + f5 * W3 - f1 * W1
59 ldrd r4, L_W0246 @ load W0, W2, W4, W6
60 add r2, r2, #1 @ f0 += 1
62 smulbb r10, r4, r2 @ a0' = W0 * f0
63 smlabb r10, r5, r3, r10 @ + W4 * f4
64 smultt r12, r4, r2 @ a3' = W2 * f2
65 smlatt r12, r5, r3, r12 @ + W6 * f6
66 add r10, r10, r12 @ a0 = a0' + a3'
67 sub r12, r10, r12, lsl #1 @ a3 = a0 - 2 * a3'
69 smulbb r11, r5, r3 @ a1' = -W4 * f4
71 smlabb r11, r4, r2, r11 @ + W0 * f0
72 smultt r3, r4, r3 @ a2' = -W2 * f6
74 smlatt r3, r5, r2, r3 @ + W6 * f2
75 add r11, r11, r3 @ a1 = a1' + a2'
76 sub r3, r11, r3, lsl #1 @ a2 = a1 - 2 * a2'
78 @ Special store order for making the column pass calculate columns in
79 @ the order 0-2-1-3-4-6-5-7, allowing for uxtab16 use in later stages.
80 sub r2, r10, r6 @ block[7] = (a0 - b0)
81 mov r2, r2, asr #12 @ >> 12
83 sub r2, r11, r7 @ block[6] = (a1 - b1)
84 mov r2, r2, asr #12 @ >> 12
86 sub r2, r3, r8 @ block[5] = (a2 - b2)
87 mov r2, r2, asr #12 @ >> 12
89 sub r2, r12, r9 @ block[4] = (a3 - b3)
90 mov r2, r2, asr #12 @ >> 12
92 add r2, r12, r9 @ block[3] = (a3 + b3)
93 mov r2, r2, asr #12 @ >> 12
95 add r2, r3, r8 @ block[2] = (a2 + b2)
96 mov r2, r2, asr #12 @ >> 12
98 add r2, r11, r7 @ block[1] = (a1 + b1)
99 mov r2, r2, asr #12 @ >> 12
101 add r2, r10, r6 @ block[0] = (a0 + b0)
102 mov r2, r2, asr #12 @ >> 12
103 strh r2, [r1], #2 @ advance to next temp column
109 @placed here because of ldrd's offset limit
123 @ r0 now points to the temp buffer, where we need it.
124 sub r1, r1, #128+16 @ point r1 back to the input block
125 mov r14, #8 @ loop counter
128 ldmia r0!, {r2, r3, r10, r11} @ fetch f0, f2, f4, f6, f1, f3, f5, f7
129 ldrd r4, L_W1357 @ load W1, W3, W5, W7
131 smuad r6, r4, r10 @ b0 = W1 * f1 + W3 * f3
132 smlad r6, r5, r11, r6 @ + W5 * f5 + W7 * f7
134 smultt r7, r5, r10 @ b1 = -W7 * f3
135 smlabb r7, r4, r11, r7 @ + -W1 * f5
136 smlabt r7, r5, r11, r7 @ + -W5 * f7
138 smlatb r7, r4, r10, r7 @ + W3 * f1
140 smulbt r8, r4, r10 @ b2 = -W1 * f3
142 smlabb r8, r5, r10, r8 @ + W5 * f1
143 smlatb r8, r5, r11, r8 @ + W7 * f5
144 smlatt r8, r4, r11, r8 @ + W3 * f7
146 smusdx r9, r10, r5 @ b3 = f1 * W7 - f3 * W5
147 smlsdx r9, r11, r4, r9 @ + f5 * W3 - f1 * W1
149 ldrd r4, L_W0246 @ load W0, W2, W4, W6
150 add r2, r2, #32 @ DC offset: 0.5
152 smulbb r10, r4, r2 @ a0' = W0 * f0
153 smlabb r10, r5, r3, r10 @ + W4 * f4
154 smultt r12, r4, r2 @ a3' = W2 * f2
155 smlatt r12, r5, r3, r12 @ + W6 * f6
156 add r10, r10, r12 @ a0 = a0' + a3'
157 sub r12, r10, r12, lsl #1 @ a3 = a0 - 2 * a3'
159 smulbb r11, r5, r3 @ a1' = -W4 * f4
161 smlabb r11, r4, r2, r11 @ + W0 * f0
162 smultt r3, r4, r3 @ a2' = -W2 * f6
164 smlatt r3, r5, r2, r3 @ + W6 * f2
165 add r11, r11, r3 @ a1 = a1' + a2'
166 sub r3, r11, r3, lsl #1 @ a2 = a1 - 2 * a2'
168 sub r2, r10, r6 @ block[7] = (a0 - b0)
169 mov r2, r2, asr #17 @ >> 17
171 sub r2, r11, r7 @ block[6] = (a1 - b1)
172 mov r2, r2, asr #17 @ >> 17
174 sub r2, r3, r8 @ block[5] = (a2 - b2)
175 mov r2, r2, asr #17 @ >> 17
177 sub r2, r12, r9 @ block[4] = (a3 - b3)
178 mov r2, r2, asr #17 @ >> 17
180 add r2, r12, r9 @ block[3] = (a3 + b3)
181 mov r2, r2, asr #17 @ >> 17
183 add r2, r3, r8 @ block[2] = (a2 + b2)
184 mov r2, r2, asr #17 @ >> 17
186 add r2, r11, r7 @ block[1] = (a1 + b1)
187 mov r2, r2, asr #17 @ >> 17
189 add r2, r10, r6 @ block[0] = (a0 + b0)
190 mov r2, r2, asr #17 @ >> 17
191 strh r2, [r1], #2 @ advance to next column
196 sub r0, r0, #256 @ point r0 back to the input block
201 stmfd sp!, {r1-r2, r4-r11, lr}
210 1: @ idct data is in order 0-2-1-3-4-6-5-7,
211 ldmia r0, {r4-r7} @ see above
215 orr r4, r4, r5, lsl #8
218 orr r5, r6, r7, lsl #8
219 strd r4, [r1] @ r4, r5
224 ldmfd sp!, {r4-r11, pc}
235 stmfd sp!, {r2-r11, lr}
244 ldrd r8, [r1] @ r8, r9
245 2: @ idct data is in order 0-2-1-3-4-6-5-7,
246 ldmia r0, {r4-r7} @ see above
247 stmia r0!, {r10-r12, lr}
249 uxtab16 r5, r5, r8, ror #8
252 orr r4, r4, r5, lsl #8
254 uxtab16 r7, r7, r9, ror #8
257 orr r5, r6, r7, lsl #8
258 strd r4, [r1] @ r4, r5
261 ldrlod r8, [r1] @ r8, r9
264 ldmfd sp!, {r4-r11, pc}
268 ldrsh r4, [r0, #0] @ r4 = block[0]
270 strh r12, [r0, #0] @ block[0] = 0
271 strh r12, [r0, #126] @ block[63] = 0
273 mov r4, r4, asr #7 @ r4 = DC
274 mov r4, r4, lsl #16 @ spread to 2 halfwords
275 orr r4, r4, r4, lsr #16
276 ldrd r0, [r2] @ r0, r1
277 add r12, r2, r3, asl #3
279 uxtab16 lr, r4, r0, ror #8
283 orr r0, r0, lr, lsl #8
284 uxtab16 lr, r4, r1, ror #8
288 orr r1, r1, lr, lsl #8
289 strd r0, [r2] @ r0, r1
292 ldrlod r0, [r2] @ r0, r1