1 @// 2 @// Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. 3 @// 4 @// Use of this source code is governed by a BSD-style license 5 @// that can be found in the LICENSE file in the root of the source 6 @// tree. An additional intellectual property rights grant can be found 7 @// in the file PATENTS. All contributing project authors may 8 @// be found in the AUTHORS file in the root of the source tree. 9 @// 10 @// This file was originally licensed as follows. It has been 11 @// relicensed with permission from the copyright holders. 12 @// 13 @// 14 @// File Name: omxSP_FFTFwd_CToC_SC32_Sfs_s.s 15 @// OpenMAX DL: v1.0.2 16 @// Last Modified Revision: 6684 17 @// Last Modified Date: Mon, 09 Jul 2007 18 @// 19 @// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. 20 @// 21 @// 22 @// 23 @// Description: 24 @// Compute an inverse FFT for a complex signal 25 @// 26 27 28 @// Include standard headers 29 30 #include "dl/api/arm/armCOMM_s.h" 31 #include "dl/api/arm/omxtypes_s.h" 32 33 @// Import symbols required from other files 34 @// (For example tables) 35 36 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe 37 .extern armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe 38 .extern armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe 39 .extern armSP_FFTFwd_CToC_SC32_Radix8_fs_OutOfPlace_unsafe 40 .extern armSP_FFTFwd_CToC_SC32_Radix4_OutOfPlace_unsafe 41 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe 42 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix8_fs_OutOfPlace_unsafe 43 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix4_OutOfPlace_unsafe 44 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe 45 .extern armSP_FFTFwd_CToC_SC32_Radix2_OutOfPlace_unsafe 46 47 @// Set debugging level 48 @//DEBUG_ON SETL {TRUE} 49 50 51 52 @// Guarding implementation by the processor name 53 54 55 56 @// Guarding implementation by the processor name 57 58 @// Import symbols required from other files 59 @// (For example tables) 60 .extern armSP_FFTFwd_CToC_SC32_Radix4_ls_OutOfPlace_unsafe 61 .extern armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe 62 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix4_ls_OutOfPlace_unsafe 63 .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe 64 65 66 @//Input Registers 67 68 #define pSrc r0 69 #define pDst r1 70 #define pFFTSpec r2 71 #define scale r3 72 73 74 @// Output registers 75 #define result r0 76 77 @//Local Scratch Registers 78 79 #define argTwiddle r1 80 #define argDst r2 81 #define argScale r4 82 #define tmpOrder r4 83 #define pTwiddle r4 84 #define pOut r5 85 #define subFFTSize r7 86 #define subFFTNum r6 87 #define N r6 88 #define order r14 89 #define diff r9 90 @// Total num of radix stages required to comple the FFT 91 #define count r8 92 #define x0r r4 93 #define x0i r5 94 #define diffMinusOne r2 95 #define round r3 96 97 @// Neon registers 98 99 #define dX0 D0.S32 100 #define dShift D1.S32 101 102 103 104 @// Allocate stack memory required by the function 105 M_ALLOC4 diffOnStack, 4 106 107 @// Write function header 108 M_START omxSP_FFTFwd_CToC_SC32_Sfs,r11,d15 109 110 @ Structure offsets for the FFTSpec 111 .set ARMsFFTSpec_N, 0 112 .set ARMsFFTSpec_pBitRev, 4 113 .set ARMsFFTSpec_pTwiddle, 8 114 .set ARMsFFTSpec_pBuf, 12 115 116 @// Define stack arguments 117 118 @// Read the size from structure and take log 119 LDR N, [pFFTSpec, #ARMsFFTSpec_N] 120 121 @// Read other structure parameters 122 LDR pTwiddle, [pFFTSpec, #ARMsFFTSpec_pTwiddle] 123 LDR pOut, [pFFTSpec, #ARMsFFTSpec_pBuf] 124 125 CLZ order,N @// N = 2^order 126 RSB order,order,#31 127 MOV subFFTSize,#1 128 @//MOV subFFTNum,N 129 130 CMP order,#3 131 BGT orderGreaterthan3 @// order > 3 132 133 CMP order,#1 134 BGE orderGreaterthan0 @// order > 0 135 M_STR scale, diffOnStack,LT @// order = 0 136 VLD1 dX0,[pSrc] 137 VST1 dX0,[pDst] 138 MOV pSrc,pDst 139 BLT FFTEnd 140 141 orderGreaterthan0: 142 @// set the buffers appropriately for various orders 143 CMP order,#2 144 MOVNE argDst,pDst 145 MOVEQ argDst,pOut 146 MOVEQ pOut,pDst @// Pass the first stage destination in RN5 147 MOV argTwiddle,pTwiddle 148 149 SUBS diff,scale,order 150 M_STR diff,diffOnStack 151 MOVGT scale,order 152 @// Now scale <= order 153 154 CMP order,#1 155 BGT orderGreaterthan1 156 SUBS scale,scale,#1 157 BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// order = 1 158 BLLT armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe @// order = 1 159 B FFTEnd 160 161 orderGreaterthan1: 162 CMP order,#2 163 MOV argScale,scale 164 BGT orderGreaterthan2 165 SUBS argScale,argScale,#1 166 BLGE armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// order =2 167 BLLT armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe 168 SUBS argScale,argScale,#1 169 BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe 170 BLLT armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe 171 B FFTEnd 172 173 orderGreaterthan2: @// order =3 174 SUBS argScale,argScale,#1 175 BLGE armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe // "fs" means first stage 176 BLLT armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe 177 SUBS argScale,argScale,#1 178 BLGE armSP_FFTFwd_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe 179 BLLT armSP_FFTFwd_CToC_SC32_Radix2_OutOfPlace_unsafe 180 SUBS argScale,argScale,#1 181 BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe // "ls" means last stage 182 BLLT armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe 183 B FFTEnd 184 185 186 187 orderGreaterthan3: 188 @// check scale = 0 or scale = order 189 SUBS diff, scale, order @// scale > order 190 MOVGT scale,order 191 BGE specialScaleCase @// scale = 0 or scale = order 192 CMP scale,#0 193 BEQ specialScaleCase 194 B generalScaleCase 195 196 specialScaleCase: @// scale = 0 or scale = order and order >= 2 197 198 TST order, #2 @// Set input args to fft stages 199 MOVNE argDst,pDst 200 MOVEQ argDst,pOut 201 MOVEQ pOut,pDst @// Pass the first stage destination in RN5 202 MOV argTwiddle,pTwiddle 203 204 CMP diff,#0 205 M_STR diff, diffOnStack 206 BGE scaleEqualsOrder 207 208 @//check for even or odd order 209 @// NOTE: The following combination of BL's would work fine eventhough the first 210 @// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside 211 @// armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ 212 213 TST order,#0x00000001 214 BLEQ armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe 215 BLNE armSP_FFTFwd_CToC_SC32_Radix8_fs_OutOfPlace_unsafe 216 217 CMP subFFTNum,#4 218 BLT FFTEnd 219 220 221 unscaledRadix4Loop: 222 BEQ lastStageUnscaledRadix4 223 BL armSP_FFTFwd_CToC_SC32_Radix4_OutOfPlace_unsafe 224 CMP subFFTNum,#4 225 B unscaledRadix4Loop 226 227 lastStageUnscaledRadix4: 228 BL armSP_FFTFwd_CToC_SC32_Radix4_ls_OutOfPlace_unsafe 229 B FFTEnd 230 231 232 scaleEqualsOrder: 233 @//check for even or odd order 234 @// NOTE: The following combination of BL's would work fine eventhough the first 235 @// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside 236 @// armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ 237 238 TST order,#0x00000001 239 BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe 240 BLNE armSP_FFTFwd_CToC_SC32_Sfs_Radix8_fs_OutOfPlace_unsafe 241 242 CMP subFFTNum,#4 243 BLT FFTEnd 244 245 246 scaledRadix4Loop: 247 BEQ lastStageScaledRadix4 248 BL armSP_FFTFwd_CToC_SC32_Sfs_Radix4_OutOfPlace_unsafe 249 CMP subFFTNum,#4 250 B scaledRadix4Loop 251 252 lastStageScaledRadix4: 253 BL armSP_FFTFwd_CToC_SC32_Sfs_Radix4_ls_OutOfPlace_unsafe 254 B FFTEnd 255 256 generalScaleCase: @// 0 < scale < order and order >= 2 257 @// Determine the correct destination buffer 258 SUB diff,order,scale 259 TST diff,#0x01 260 ADDEQ count,scale,diff,LSR #1 @// count = scale + (order - scale)/2 261 MOVNE count,order 262 TST count,#0x01 @// Is count even or odd ? 263 264 MOVNE argDst,pDst @// Set input args to fft stages 265 MOVEQ argDst,pOut 266 MOVEQ pOut,pDst @// Pass the first stage destination in RN5 267 MOV argTwiddle,pTwiddle 268 269 M_STR diff, diffOnStack 270 271 MOV argScale,scale @// Put scale in RN4 so as to save and restore 272 BL armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// scaled first stage 273 SUBS argScale,argScale,#1 274 275 scaledRadix2Loop: 276 BLGT armSP_FFTFwd_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe 277 SUBS argScale,argScale,#1 @// save and restore scale (RN4) in the scaled stages 278 BGT scaledRadix2Loop 279 280 281 M_LDR diff, diffOnStack 282 @//check for even or odd order 283 TST diff,#0x00000001 284 BEQ generalUnscaledRadix4Loop 285 B unscaledRadix2Loop 286 287 generalUnscaledRadix4Loop: 288 CMP subFFTNum,#4 289 BEQ generalLastStageUnscaledRadix4 290 BL armSP_FFTFwd_CToC_SC32_Radix4_OutOfPlace_unsafe 291 B generalUnscaledRadix4Loop 292 293 generalLastStageUnscaledRadix4: 294 BL armSP_FFTFwd_CToC_SC32_Radix4_ls_OutOfPlace_unsafe 295 B End 296 297 298 unscaledRadix2Loop: 299 CMP subFFTNum,#2 300 BEQ generalLastStageUnscaledRadix2 301 BL armSP_FFTFwd_CToC_SC32_Radix2_OutOfPlace_unsafe 302 B unscaledRadix2Loop 303 304 generalLastStageUnscaledRadix2: 305 BL armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe 306 B End 307 308 309 FFTEnd: @// Does only the scaling 310 311 M_LDR diff, diffOnStack 312 CMP diff,#0 313 BLE End 314 315 RSB diff,diff,#0 @// to use VRSHL for right shift by a variable 316 VDUP dShift,diff 317 318 scaleFFTData: @// N = subFFTSize ; dataptr = pDst ; scale = diff 319 VLD1 {dX0},[pSrc] @// pSrc contains pDst pointer 320 SUBS subFFTSize,subFFTSize,#1 321 VRSHL dX0,dShift 322 VST1 {dX0},[pSrc]! 323 324 BGT scaleFFTData 325 326 327 328 End: 329 @// Set return value 330 MOV result, #OMX_Sts_NoErr 331 332 @// Write function tail 333 M_END 334 335 .end 336
