Statistics
| Branch: | Revision:

ffmpeg / libavcodec / bfin / vp3_idct_bfin.S @ 2912e87a

History | View | Annotate | Download (10.3 KB)

1
/*
2
 * vp3_idct BlackFin
3
 *
4
 * Copyright (C) 2007 Marc Hoffman <marc.hoffman@analog.com>
5
 *
6
 * This file is part of Libav.
7
 *
8
 * Libav is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * Libav is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with Libav; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22
/*
23
   This blackfin DSP code implements an 8x8 inverse type II DCT.
24

    
25
Prototype       : void ff_bfin_vp3_idct(DCTELEM *in)
26

    
27
Registers Used  : A0, A1, R0-R7, I0-I3, B0, B2, B3, M0-M2, L0-L3, P0-P5, LC0.
28

    
29
*/
30

    
31
#include "config.h"
32
#include "config_bfin.h"
33

    
34
#if defined(__FDPIC__) && CONFIG_SRAM
35
.section .l1.data.B,"aw",@progbits
36
#else
37
.data
38
#endif
39

    
40
.align 4;
41
coefs:
42
.short 0x5a82;           //  C4
43
.short 0x5a82;           //  C4
44
.short 0x30FC;           //cos(3pi/8)  C6
45
.short 0x7642;           //cos(pi/8)   C2
46
.short 0x18F9;           //cos(7pi/16)
47
.short 0x7D8A;           //cos(pi/16)
48
.short 0x471D;           //cos(5pi/16)
49
.short 0x6A6E;           //cos(3pi/16)
50
.short 0x18F9;           //cos(7pi/16)
51
.short 0x7D8A;           //cos(pi/16)
52

    
53
#if defined(__FDPIC__) && CONFIG_SRAM
54
.section .l1.data.A
55
#endif
56

    
57
vtmp: .space 256
58

    
59
#define TMP0 FP-8
60
#define TMP1 FP-12
61
#define TMP2 FP-16
62

    
63

    
64
.text
65
DEFUN(vp3_idct,mL1,
66
        (DCTELEM *block)):
67

    
68
/********************** Function Prologue *********************************/
69
    link 16;
70
    [--SP] = (R7:4, P5:3);   // Push the registers onto the stack.
71
    B0 = R0;                 // Pointer to Input matrix
72
    RELOC(R1, P3, coefs);    // Pointer to Coefficients
73
    RELOC(R2, P3, vtmp);     // Pointer to Temporary matrix
74
    B3 = R1;
75
    B2 = R2;
76
    L3 = 20;                // L3 is used for making the coefficient array
77
                            // circular.
78
                            // MUST BE RESTORED TO ZERO at function exit.
79
    M1 = 16 (X);            // All these registers are initialized for
80
    M3 = 8(X);              // modifying address offsets.
81

    
82
    I0 = B0;                // I0 points to Input Element (0, 0).
83
    I2 = B0;                // I2 points to Input Element (0, 0).
84
    I2 += M3 || R0.H = W[I0];
85
                            // Element 0 is read into R0.H
86
    I1 = I2;                // I1 points to input Element (0, 6).
87
    I1 += 4  || R0.L = W[I2++];
88
                            // I2 points to input Element (0, 4).
89
                            // Element 4 is read into R0.L.
90
    P2 = 8 (X);
91
    P3 = 32 (X);
92
    P4 = -32 (X);
93
    P5 = 98 (X);
94
    R7 = 0x8000(Z);
95
    I3 = B3;                // I3 points to Coefficients
96
    P0 = B2;                // P0 points to array Element (0, 0) of temp
97
    P1 = B2;
98
    R7 = [I3++] || [TMP2]=R7;            // Coefficient C4 is read into R7.H and R7.L.
99
    MNOP;
100
    NOP;
101

    
102
    /*
103
     *   A1 =      Y0 * cos(pi/4)
104
     *   A0 =      Y0 * cos(pi/4)
105
     *   A1 = A1 + Y4 * cos(pi/4)
106
     *   A0 = A0 - Y4 * cos(pi/4)
107
     *   load:
108
     *     R1=(Y2,Y6)
109
     *     R7=(C2,C6)
110
     *   res:
111
     *     R3=Y0, R2=Y4
112
     */
113
    A1=R7.H*R0.H,       A0=R7.H*R0.H (IS)       || I0+= 4       || R1.L=W[I1++];
114
    R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || R1.H=W[I0--] || R7=[I3++];
115

    
116
    LSETUP (.0, .1) LC0 = P2; // perform 8 1d idcts
117

    
118
    P2 = 112 (X);
119
    P1 = P1 + P2;           // P1 points to element (7, 0) of temp buffer.
120
    P2 = -94(X);
121

    
122
.0:
123
       /*
124
        *   A1 =      Y2 * cos(3pi/8)
125
        *   A0 =      Y2 * cos(pi/8)
126
        *   A1 = A1 - Y6 * cos(pi/8)
127
        *   A0 = A0 + Y6 * cos(3pi/8)
128
        *      R5 = (Y1,Y7)
129
        *      R7 = (C1,C7)
130
        *   res:
131
        *      R1=Y2, R0=Y6
132
        */
133
        A1=R7.L*R1.H,       A0=R7.H*R1.H (IS)        || I0+=4        || R5.H=W[I0];
134
        R1=(A1-=R7.H*R1.L), R0=(A0+=R7.L*R1.L) (IS)  || R5.L=W[I1--] || R7=[I3++];
135
        /*
136
        *   Y0 = Y0 + Y6.
137
        *   Y4 = Y4 + Y2.
138
        *   Y2 = Y4 - Y2.
139
        *   Y6 = Y0 - Y6.
140
        *     R3 is saved
141
        *     R6.l=Y3
142
        * note: R3: Y0, R2: Y4, R1: Y2, R0: Y6
143
        */
144
        R3=R3+R0, R0=R3-R0;
145
        R2=R2+R1, R1=R2-R1 || [TMP0]=R3 || R6.L=W[I0--];
146
        /*
147
         *  Compute the odd portion (1,3,5,7) even is done.
148
         *
149
         *  Y1 = C7 * Y1 - C1 * Y7 + C3 * Y5 - C5 * Y3.
150
         *  Y7 = C1 * Y1 + C7 * Y7 + C5 * Y5 + C3 * Y3.
151
         *  Y5 = C5 * Y1 + C3 * Y7 + C7 * Y5 - C1 * Y3.
152
         *  Y3 = C3 * Y1 - C5 * Y7 - C1 * Y5 - C7 * Y3.
153
         */
154
        //  R5=(Y1,Y7)  R6=(Y5,Y3)                                                   // R7=(C1,C7)
155
        A1 =R7.L*R5.H,       A0 =R7.H*R5.H (IS)       || [TMP1]=R2 || R6.H=W[I2--];
156
        A1-=R7.H*R5.L,       A0+=R7.L*R5.L (IS)       || I0-=4     || R7=[I3++];
157
        A1+=R7.H*R6.H,       A0+=R7.L*R6.H (IS)       || I0+=M1;                     // R7=(C3,C5)
158
        R3 =(A1-=R7.L*R6.L), R2 =(A0+=R7.H*R6.L) (IS);
159
        A1 =R7.L*R5.H,       A0 =R7.H*R5.H (IS)       || R4=[TMP0];
160
        A1+=R7.H*R5.L,       A0-=R7.L*R5.L (IS)       || I1+=M1    || R7=[I3++];     // R7=(C1,C7)
161
        A1+=R7.L*R6.H,       A0-=R7.H*R6.H (IS);
162
        R7 =(A1-=R7.H*R6.L), R6 =(A0-=R7.L*R6.L) (IS) || I2+=M1;
163
        // R3=Y1, R2=Y7, R7=Y5, R6=Y3
164

    
165
        /* Transpose write column. */
166
        R5.H=R4+R2 (RND12);                                   // Y0=Y0+Y7
167
        R5.L=R4-R2 (RND12) || R4 = [TMP1];                    // Y7=Y7-Y0
168
        R2.H=R1+R7 (RND12) || W[P0++P3]=R5.H;                 // Y2=Y2+Y5 st Y0
169
        R2.L=R1-R7 (RND12) || W[P1++P4]=R5.L || R7=[I3++];    // Y5=Y2-Y5 st Y7
170
        R5.H=R0-R3 (RND12) || W[P0++P3]=R2.H || R1.L=W[I1++]; // Y1=Y6-Y1 st Y2
171
        R5.L=R0+R3 (RND12) || W[P1++P4]=R2.L || R0.H=W[I0++]; // Y6=Y6+Y1 st Y5
172
        R3.H=R4-R6 (RND12) || W[P0++P3]=R5.H || R0.L=W[I2++]; // Y3=Y3-Y4 st Y1
173
        R3.L=R4+R6 (RND12) || W[P1++P4]=R5.L || R1.H=W[I0++]; // Y4=Y3+Y4 st Y6
174

    
175
        /* pipeline loop start, + drain Y3, Y4 */
176
        A1=R7.H*R0.H,       A0=R7.H*R0.H (IS)       || W[P0++P2]= R3.H || R1.H = W[I0--];
177
.1:     R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || W[P1++P5]= R3.L || R7 = [I3++];
178

    
179

    
180

    
181
    I0 = B2;                // I0 points to Input Element (0, 0)
182
    I2 = B2;                // I2 points to Input Element (0, 0)
183
    I2 += M3 || R0.H = W[I0];
184
                            // Y0 is read in R0.H
185
    I1 = I2;                // I1 points to input Element (0, 6)
186
    I1 += 4  || R0.L = W[I2++];
187
                            // I2 points to input Element (0, 4)
188
                            // Y4 is read in R0.L
189
    P2 = 8 (X);
190
    I3 = B3;                // I3 points to Coefficients
191
    P0 = B0;                // P0 points to array Element (0, 0) for writing
192
                            // output
193
    P1 = B0;
194
    R7 = [I3++];            // R7.H = C4 and R7.L = C4
195
    NOP;
196

    
197
    /*
198
     *   A1 =      Y0 * cos(pi/4)
199
     *   A0 =      Y0 * cos(pi/4)
200
     *   A1 = A1 + Y4 * cos(pi/4)
201
     *   A0 = A0 - Y4 * cos(pi/4)
202
     *   load:
203
     *     R1=(Y2,Y6)
204
     *     R7=(C2,C6)
205
     *   res:
206
     *     R3=Y0, R2=Y4
207
     */
208
    A1=R7.H*R0.H,       A0=R7.H*R0.H (IS)       || I0+=4        || R1.L=W[I1++];
209
    R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || R1.H=W[I0--] || R7=[I3++];
210

    
211
    LSETUP (.2, .3) LC0 = P2; // peform 8 1d idcts
212
    P2 = 112 (X);
213
    P1 = P1 + P2;
214
    P2 = -94(X);
215

    
216
.2:
217
        /*
218
         *   A1 =      Y2 * cos(3pi/8)
219
         *   A0 =      Y2 * cos(pi/8)
220
         *   A1 = A1 - Y6 * cos(pi/8)
221
         *   A0 = A0 + Y6 * cos(3pi/8)
222
         *      R5 = (Y1,Y7)
223
         *      R7 = (C1,C7)
224
         *   res:
225
         *      R1=Y2, R0=Y6
226
         */
227
        A1=R7.L*R1.H,       A0=R7.H*R1.H (IS)        || I0+=4        || R5.H=W[I0];
228
        R1=(A1-=R7.H*R1.L), R0=(A0+=R7.L*R1.L) (IS)  || R5.L=W[I1--] || R7=[I3++];
229
        /*
230
        *   Y0 = Y0 + Y6.
231
        *   Y4 = Y4 + Y2.
232
        *   Y2 = Y4 - Y2.
233
        *   Y6 = Y0 - Y6.
234
        *     R3 is saved
235
        *     R6.l=Y3
236
        * note: R3: Y0, R2: Y4, R1: Y2, R0: Y6
237
        */
238
        R3=R3+R0, R0=R3-R0;
239
        R2=R2+R1, R1=R2-R1 || [TMP0]=R3 || R6.L=W[I0--];
240
        /*
241
         *  Compute the odd portion (1,3,5,7) even is done.
242
         *
243
         *  Y1 = C7 * Y1 - C1 * Y7 + C3 * Y5 - C5 * Y3.
244
         *  Y7 = C1 * Y1 + C7 * Y7 + C5 * Y5 + C3 * Y3.
245
         *  Y5 = C5 * Y1 + C3 * Y7 + C7 * Y5 - C1 * Y3.
246
         *  Y3 = C3 * Y1 - C5 * Y7 - C1 * Y5 - C7 * Y3.
247
         */
248
        //  R5=(Y1,Y7)  R6=(Y5,Y3)                                                   // R7=(C1,C7)
249
        A1 =R7.L*R5.H,       A0 =R7.H*R5.H (IS)       || [TMP1]=R2 || R6.H=W[I2--];
250
        A1-=R7.H*R5.L,       A0+=R7.L*R5.L (IS)       || I0-=4     || R7=[I3++];
251
        A1+=R7.H*R6.H,       A0+=R7.L*R6.H (IS)       || I0+=M1;                     // R7=(C3,C5)
252
        R3 =(A1-=R7.L*R6.L), R2 =(A0+=R7.H*R6.L) (IS);
253
        A1 =R7.L*R5.H,       A0 =R7.H*R5.H (IS)       || R4=[TMP0];
254
        A1+=R7.H*R5.L,       A0-=R7.L*R5.L (IS)       || I1+=M1    || R7=[I3++];     // R7=(C1,C7)
255
        A1+=R7.L*R6.H,       A0-=R7.H*R6.H (IS);
256
        R7 =(A1-=R7.H*R6.L), R6 =(A0-=R7.L*R6.L) (IS) || I2+=M1;
257
        // R3=Y1, R2=Y7, R7=Y5, R6=Y3
258

    
259
        /* Transpose write column. */
260
        R5.H=R4+R2 (RND20);                                   // Y0=Y0+Y7
261
        R5.L=R4-R2 (RND20) || R4 = [TMP1];                    // Y7=Y7-Y0
262
        R5=R5>>>2(v);
263
        R2.H=R1+R7 (RND20) || W[P0++P3]=R5.H;                 // Y2=Y2+Y5 st Y0
264
        R2.L=R1-R7 (RND20) || W[P1++P4]=R5.L || R7=[I3++];    // Y5=Y2-Y5 st Y7
265
        R2=R2>>>2(v);
266
        R5.H=R0-R3 (RND20) || W[P0++P3]=R2.H || R1.L=W[I1++]; // Y1=Y6-Y1 st Y2
267
        R5.L=R0+R3 (RND20) || W[P1++P4]=R2.L || R0.H=W[I0++]; // Y6=Y6+Y1 st Y5
268
        R5=R5>>>2(v);
269
        R3.H=R4-R6 (RND20) || W[P0++P3]=R5.H || R0.L=W[I2++]; // Y3=Y3-Y4 st Y1
270
        R3.L=R4+R6 (RND20) || W[P1++P4]=R5.L || R1.H=W[I0++]; // Y4=Y3+Y4 st Y6
271
        R3=R3>>>2(v);
272
        /* pipeline loop start, + drain Y3, Y4 */
273
        A1=R7.H*R0.H,       A0=R7.H*R0.H (IS)       || W[P0++P2]= R3.H || R1.H = W[I0--];
274
.3:     R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || W[P1++P5]= R3.L || R7 = [I3++];
275

    
276
    L3 = 0;
277
    (R7:4,P5:3)=[SP++];
278
    unlink;
279
    RTS;
280
DEFUN_END(vp3_idct)
281

    
282