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 25Prototype : void ff_bfin_vp3_idct(DCTELEM *in) 26 27Registers 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; 41coefs: 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 57vtmp: .space 256 58 59#define TMP0 FP-8 60#define TMP1 FP-12 61#define TMP2 FP-16 62 63 64.text 65DEFUN(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; 280DEFUN_END(vp3_idct) 281 282 283