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 @// 15 @// File Name: omxSP_FFTFwd_CToC_SC16_Sfs_s.s 16 @// OpenMAX DL: v1.0.2 17 @// Last Modified Revision: 6729 18 @// Last Modified Date: Tue, 17 Jul 2007 19 @// 20 @// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. 21 @// 22 @// 23 @// 24 @// Description: 25 @// Compute an inverse FFT for a complex signal 26 @// 27 @// 28 29 30 @// Include standard headers 31 32 #include "dl/api/arm/armCOMM_s.h" 33 #include "dl/api/arm/omxtypes_s.h" 34 35 36 @// Import symbols required from other files 37 @// (For example tables) 38 39 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix2_fs_OutOfPlace_unsafe 40 .extern armSP_FFTFwd_CToC_SC16_Radix2_fs_OutOfPlace_unsafe 41 .extern armSP_FFTFwd_CToC_SC16_Radix4_fs_OutOfPlace_unsafe 42 .extern armSP_FFTFwd_CToC_SC16_Radix4_ls_OutOfPlace_unsafe 43 .extern armSP_FFTFwd_CToC_SC16_Radix8_fs_OutOfPlace_unsafe 44 .extern armSP_FFTFwd_CToC_SC16_Radix4_OutOfPlace_unsafe 45 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix4_fs_OutOfPlace_unsafe 46 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix4_ls_OutOfPlace_unsafe 47 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix8_fs_OutOfPlace_unsafe 48 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix4_OutOfPlace_unsafe 49 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix2_OutOfPlace_unsafe 50 .extern armSP_FFTFwd_CToC_SC16_Radix2_OutOfPlace_unsafe 51 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix2_ls_OutOfPlace_unsafe 52 .extern armSP_FFTFwd_CToC_SC16_Radix2_ls_OutOfPlace_unsafe 53 54 @// Set debugging level 55 @//DEBUG_ON SETL {TRUE} 56 57 58 59 @// Guarding implementation by the processor name 60 61 62 63 @// Guarding implementation by the processor name 64 65 66 .extern armSP_FFTFwd_CToC_SC16_Radix2_ps_OutOfPlace_unsafe 67 .extern armSP_FFTFwd_CToC_SC16_Sfs_Radix2_ps_OutOfPlace_unsafe 68 69 @//Input Registers 70 71 #define pSrc r0 72 #define pDst r1 73 #define pFFTSpec r2 74 #define scale r3 75 76 77 @// Output registers 78 #define result r0 79 80 @//Local Scratch Registers 81 #define argTwiddle r1 82 #define argDst r2 83 #define argScale r4 84 #define pTwiddle r4 85 #define tmpOrder r4 86 #define pOut r5 87 #define subFFTSize r7 88 #define subFFTNum r6 89 #define N r6 90 #define order r14 91 #define diff r9 92 @// Total num of radix stages required to comple the FFT 93 #define count r8 94 #define x0r r4 95 #define x0i r5 96 #define diffMinusOne r2 97 #define round r3 98 99 @// Neon registers 100 101 #define dX0 D0.S16 102 #define dShift D1.S16 103 #define dX0S32 D0.S32 104 105 106 107 @// Allocate stack memory required by the function 108 M_ALLOC4 diffOnStack, 4 109 110 @// Write function header 111 M_START omxSP_FFTFwd_CToC_SC16_Sfs,r11,d15 112 113 @ Structure offsets for the FFTSpec 114 .set ARMsFFTSpec_N, 0 115 .set ARMsFFTSpec_pBitRev, 4 116 .set ARMsFFTSpec_pTwiddle, 8 117 .set ARMsFFTSpec_pBuf, 12 118 119 @// Define stack arguments 120 121 @// Read the size from structure and take log 122 LDR N, [pFFTSpec, #ARMsFFTSpec_N] 123 124 @// Read other structure parameters 125 LDR pTwiddle, [pFFTSpec, #ARMsFFTSpec_pTwiddle] 126 LDR pOut, [pFFTSpec, #ARMsFFTSpec_pBuf] 127 128 CLZ order,N @// N = 2^order 129 RSB order,order,#31 130 MOV subFFTSize,#1 131 @//MOV subFFTNum,N 132 133 CMP order,#3 134 BGT orderGreaterthan3 @// order > 3 135 136 CMP order,#1 137 BGE orderGreaterthan0 @// order > 0 138 M_STR scale, diffOnStack,LT @// order = 0 139 LDRLT x0r,[pSrc] 140 STRLT x0r,[pDst] 141 MOVLT pSrc,pDst 142 BLT FFTEnd 143 144 orderGreaterthan0: 145 @// set the buffers appropriately for various orders 146 CMP order,#2 147 MOVNE argDst,pDst 148 MOVEQ argDst,pOut 149 MOVEQ pOut,pDst @// Pass the first stage destination in RN5 150 MOV argTwiddle,pTwiddle 151 152 SUBS diff,scale,order 153 M_STR diff,diffOnStack 154 MOVGT scale,order 155 @// Now scale <= order 156 157 CMP order,#1 158 BGT orderGreaterthan1 159 SUBS scale,scale,#1 160 BLEQ armSP_FFTFwd_CToC_SC16_Sfs_Radix2_fs_OutOfPlace_unsafe @// order = 1 161 BLLT armSP_FFTFwd_CToC_SC16_Radix2_fs_OutOfPlace_unsafe @// order = 1 162 B FFTEnd 163 164 orderGreaterthan1: 165 CMP order,#2 166 MOV argScale,scale 167 BGT orderGreaterthan2 168 SUBS argScale,argScale,#1 169 BLGE armSP_FFTFwd_CToC_SC16_Sfs_Radix2_fs_OutOfPlace_unsafe @// order =2 170 BLLT armSP_FFTFwd_CToC_SC16_Radix2_fs_OutOfPlace_unsafe 171 SUBS argScale,argScale,#1 172 BLEQ armSP_FFTFwd_CToC_SC16_Sfs_Radix2_ls_OutOfPlace_unsafe 173 BLLT armSP_FFTFwd_CToC_SC16_Radix2_ls_OutOfPlace_unsafe 174 B FFTEnd 175 176 orderGreaterthan2: @// order =3 177 SUBS argScale,argScale,#1 178 BLGE armSP_FFTFwd_CToC_SC16_Sfs_Radix2_fs_OutOfPlace_unsafe 179 BLLT armSP_FFTFwd_CToC_SC16_Radix2_fs_OutOfPlace_unsafe 180 SUBS argScale,argScale,#1 181 BLGE armSP_FFTFwd_CToC_SC16_Sfs_Radix2_ps_OutOfPlace_unsafe 182 BLLT armSP_FFTFwd_CToC_SC16_Radix2_ps_OutOfPlace_unsafe 183 SUBS argScale,argScale,#1 184 BLEQ armSP_FFTFwd_CToC_SC16_Sfs_Radix2_ls_OutOfPlace_unsafe 185 BLLT armSP_FFTFwd_CToC_SC16_Radix2_ls_OutOfPlace_unsafe 186 B FFTEnd 187 188 189 orderGreaterthan3: 190 @// check scale = 0 or scale = order 191 SUBS diff, scale, order @// scale > order 192 MOVGT scale,order 193 BGE specialScaleCase @// scale = 0 or scale = order 194 CMP scale,#0 195 BEQ specialScaleCase 196 B generalScaleCase 197 198 specialScaleCase: @// scale = 0 or scale = order and order > 3 199 200 TST order, #2 @// Set input args to fft stages 201 MOVNE argDst,pDst 202 MOVEQ argDst,pOut 203 MOVEQ pOut,pDst @// Pass the first stage destination in RN5 204 MOV argTwiddle,pTwiddle 205 206 CMP diff,#0 207 M_STR diff, diffOnStack 208 BGE scaleEqualsOrder 209 210 @//check for even or odd order 211 @// NOTE: The following combination of BL's would work fine eventhough the first 212 @// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside 213 @// armSP_FFTFwd_CToC_SC16_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ 214 215 TST order,#0x00000001 216 BLEQ armSP_FFTFwd_CToC_SC16_Radix4_fs_OutOfPlace_unsafe 217 BLNE armSP_FFTFwd_CToC_SC16_Radix8_fs_OutOfPlace_unsafe 218 219 CMP subFFTNum,#4 220 BLT FFTEnd 221 222 unscaledRadix4Loop: 223 BEQ lastStageUnscaledRadix4 224 BL armSP_FFTFwd_CToC_SC16_Radix4_OutOfPlace_unsafe 225 CMP subFFTNum,#4 226 B unscaledRadix4Loop 227 228 lastStageUnscaledRadix4: 229 BL armSP_FFTFwd_CToC_SC16_Radix4_ls_OutOfPlace_unsafe 230 B FFTEnd 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_SC16_Sfs_Radix4_fs_OutOfPlace_unsafe 240 BLNE armSP_FFTFwd_CToC_SC16_Sfs_Radix8_fs_OutOfPlace_unsafe 241 242 CMP subFFTNum,#4 243 BLT FFTEnd 244 245 scaledRadix4Loop: 246 BEQ lastStageScaledRadix4 247 BL armSP_FFTFwd_CToC_SC16_Sfs_Radix4_OutOfPlace_unsafe 248 CMP subFFTNum,#4 249 B scaledRadix4Loop 250 251 lastStageScaledRadix4: 252 BL armSP_FFTFwd_CToC_SC16_Sfs_Radix4_ls_OutOfPlace_unsafe 253 B FFTEnd 254 255 256 257 generalScaleCase: @// 0 < scale < order and order > 3 258 @// Determine the correct destination buffer 259 SUB diff,order,scale 260 TST diff,#0x01 261 ADDEQ count,scale,diff,LSR #1 @// count = scale + (order - scale)/2 262 MOVNE count,order 263 TST count,#0x01 @// Is count even or odd ? 264 265 MOVNE argDst,pDst @// Set input args to fft stages 266 MOVEQ argDst,pOut 267 MOVEQ pOut,pDst @// Pass the first stage destination in RN5 268 MOV argTwiddle,pTwiddle 269 270 CMP diff,#1 271 M_STR diff, diffOnStack 272 BEQ scaleps @// scaling including a radix2_ps stage 273 274 MOV argScale,scale @// Put scale in RN4 so as to save and restore 275 BL armSP_FFTFwd_CToC_SC16_Sfs_Radix2_fs_OutOfPlace_unsafe @// scaled first stage 276 SUBS argScale,argScale,#1 277 278 scaledRadix2Loop: 279 BLGT armSP_FFTFwd_CToC_SC16_Sfs_Radix2_OutOfPlace_unsafe 280 SUBS argScale,argScale,#1 @// save and restore scale (RN4) in the scaled stages 281 BGT scaledRadix2Loop 282 B outScale 283 284 scaleps: 285 SUB argScale,scale,#1 @// order>3 and diff=1 => scale >= 3 286 BL armSP_FFTFwd_CToC_SC16_Sfs_Radix2_fs_OutOfPlace_unsafe @// scaled first stage 287 SUBS argScale,argScale,#1 288 289 scaledRadix2psLoop: 290 BEQ scaledRadix2psStage 291 BLGT armSP_FFTFwd_CToC_SC16_Sfs_Radix2_OutOfPlace_unsafe 292 SUBS argScale,argScale,#1 @// save and restore scale (RN4) in the scaled stages 293 BGE scaledRadix2psLoop 294 295 scaledRadix2psStage: 296 BL armSP_FFTFwd_CToC_SC16_Sfs_Radix2_ps_OutOfPlace_unsafe 297 B generalLastStageUnscaledRadix2 298 299 300 outScale: 301 M_LDR diff, diffOnStack 302 @//check for even or odd order 303 TST diff,#0x00000001 304 BEQ generalUnscaledRadix4Loop 305 B unscaledRadix2Loop 306 307 generalUnscaledRadix4Loop: 308 CMP subFFTNum,#4 309 BEQ generalLastStageUnscaledRadix4 310 BL armSP_FFTFwd_CToC_SC16_Radix4_OutOfPlace_unsafe 311 B generalUnscaledRadix4Loop 312 313 generalLastStageUnscaledRadix4: 314 BL armSP_FFTFwd_CToC_SC16_Radix4_ls_OutOfPlace_unsafe 315 B End 316 317 unscaledRadix2Loop: 318 CMP subFFTNum,#4 319 BEQ generalLastTwoStagesUnscaledRadix2 320 BL armSP_FFTFwd_CToC_SC16_Radix2_OutOfPlace_unsafe 321 B unscaledRadix2Loop 322 323 generalLastTwoStagesUnscaledRadix2: 324 BL armSP_FFTFwd_CToC_SC16_Radix2_ps_OutOfPlace_unsafe 325 generalLastStageUnscaledRadix2: 326 BL armSP_FFTFwd_CToC_SC16_Radix2_ls_OutOfPlace_unsafe 327 B End 328 329 330 FFTEnd: @// Does only the scaling 331 332 M_LDR diff, diffOnStack 333 CMP diff,#0 334 BLE End 335 336 RSB diff,diff,#0 @// to use VRSHL for right shift by a variable 337 VDUP dShift,diff 338 339 scaleFFTData: @// N = subFFTSize ; dataptr = pDst ; scale = diff 340 VLD1 {dX0S32[0]},[pSrc] @// pSrc contains pDst pointer 341 SUBS subFFTSize,subFFTSize,#1 342 VRSHL dX0,dShift 343 VST1 {dX0S32[0]},[pSrc]! 344 345 BGT scaleFFTData 346 347 348 349 End: 350 @// Set return value 351 MOV result, #OMX_Sts_NoErr 352 353 @// Write function tail 354 M_END 355 356 .end 357
