1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
|
@//
@// Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
@//
@// Use of this source code is governed by a BSD-style license
@// that can be found in the LICENSE file in the root of the source
@// tree. An additional intellectual property rights grant can be found
@// in the file PATENTS. All contributing project authors may
@// be found in the AUTHORS file in the root of the source tree.
@//
@// This file was originally licensed as follows. It has been
@// relicensed with permission from the copyright holders.
@//
@//
@// File Name: omxSP_FFTInv_CCSToR_S32_Sfs_s.s
@// OpenMAX DL: v1.0.2
@// Last Modified Revision: 7469
@// Last Modified Date: Thu, 20 Sep 2007
@//
@// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
@//
@//
@//
@// Description:
@// Compute an inverse FFT for a complex signal
@//
@// Include standard headers
#include "dl/api/armCOMM_s.h"
#include "dl/api/omxtypes_s.h"
@// Import symbols required from other files
@// (For example tables)
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Radix2_fs_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Radix4_fs_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Radix8_fs_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Radix4_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix8_fs_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix4_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Radix2_OutOfPlace_unsafe
.extern armSP_FFTInv_CCSToR_S32_Sfs_preTwiddleRadix2_unsafe
.extern armSP_FFTInv_CCSToR_S32_preTwiddleRadix2_unsafe
@// Set debugging level
@//DEBUG_ON SETL {TRUE}
@// Guarding implementation by the processor name
@// Guarding implementation by the processor name
@// Import symbols required from other files
@// (For example tables)
.extern armSP_FFTInv_CToC_SC32_Radix4_ls_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Radix2_ls_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe
.extern armSP_FFTInv_CToC_SC32_Sfs_Radix4_ls_OutOfPlace_unsafe
@//Input Registers
#define pSrc r0
#define pDst r1
#define pFFTSpec r2
#define scale r3
@// Output registers
#define result r0
@//Local Scratch Registers
#define argTwiddle r1
#define argDst r2
#define argScale r4
#define tmpOrder r4
#define pTwiddle r4
#define pOut r5
#define subFFTSize r7
#define subFFTNum r6
#define N r6
#define order r14
#define diff r9
@// Total num of radix stages required to comple the FFT
#define count r8
#define x0r r4
#define x0i r5
#define diffMinusOne r2
#define round r3
#define pOut1 r2
#define size r7
#define step r8
#define step1 r9
#define twStep r10
#define pTwiddleTmp r11
#define argTwiddle1 r12
#define zero r14
@// Neon registers
#define dX0 D0.S32
#define dShift D1.S32
#define dX1 D1.S32
#define dY0 D2.S32
#define dY1 D3.S32
#define dX0r D0.S32
#define dX0i D1.S32
#define dX1r D2.S32
#define dX1i D3.S32
#define dW0r D4.S32
#define dW0i D5.S32
#define dW1r D6.S32
#define dW1i D7.S32
#define dT0 D8.S32
#define dT1 D9.S32
#define dT2 D10.S32
#define dT3 D11.S32
#define qT0 Q6.S64
#define qT1 Q7.S64
#define qT2 Q8.S64
#define qT3 Q9.S64
#define dY0r D4.S32
#define dY0i D5.S32
#define dY1r D6.S32
#define dY1i D7.S32
#define dzero D20.S32
#define dY2 D4.S32
#define dY3 D5.S32
#define dW0 D6.S32
#define dW1 D7.S32
#define dW0Tmp D10.S32
#define dW1Neg D11.S32
@// Allocate stack memory required by the function
M_ALLOC4 diffOnStack, 4
@// Write function header
M_START omxSP_FFTInv_CCSToR_S32_Sfs,r11,d15
@ Structure offsets for the FFTSpec
.set ARMsFFTSpec_N, 0
.set ARMsFFTSpec_pBitRev, 4
.set ARMsFFTSpec_pTwiddle, 8
.set ARMsFFTSpec_pBuf, 12
@// Define stack arguments
@// Read the size from structure and take log
LDR N, [pFFTSpec, #ARMsFFTSpec_N]
@// Read other structure parameters
LDR pTwiddle, [pFFTSpec, #ARMsFFTSpec_pTwiddle]
LDR pOut, [pFFTSpec, #ARMsFFTSpec_pBuf]
@// N=1 Treat seperately
CMP N,#1
BGT sizeGreaterThanOne
VLD1 dX0[0],[pSrc]
RSB scale,scale,#0 @// to use VRSHL for right shift by a variable
VMOV dShift[0],scale
VRSHL dX0,dShift
VST1 dX0[0],[pDst]
B End
sizeGreaterThanOne:
@// Call the preTwiddle Radix2 stage before doing the compledIFFT
@// The following conditional BL combination would work since
@// evenOddButterflyLoop in the first call would set Z flag to zero
CMP scale,#0
BLEQ armSP_FFTInv_CCSToR_S32_preTwiddleRadix2_unsafe
BLGT armSP_FFTInv_CCSToR_S32_Sfs_preTwiddleRadix2_unsafe
complexIFFT:
ASR N,N,#1 @// N/2 point complex IFFT
ADD pSrc,pOut,N,LSL #3 @// set pSrc as pOut1
CLZ order,N @// N = 2^order
RSB order,order,#31
MOV subFFTSize,#1
@//MOV subFFTNum,N
ADD scale,scale,order @// FFTInverse has a final scaling factor by N
CMP order,#3
BGT orderGreaterthan3 @// order > 3
CMP order,#1
BGE orderGreaterthan0 @// order > 0
M_STR scale, diffOnStack,LT @// order = 0
VLD1 dX0,[pSrc]
VST1 dX0,[pDst]
MOV pSrc,pDst
BLT FFTEnd
orderGreaterthan0:
@// set the buffers appropriately for various orders
CMP order,#2
MOVNE argDst,pDst
MOVEQ argDst,pOut
MOVEQ pOut,pDst @// Pass the first stage destination in RN5
MOV argTwiddle,pTwiddle
@// Store the scale factor and scale at the end
SUB diff,scale,order
M_STR diff, diffOnStack
BGE orderGreaterthan1
BLLT armSP_FFTInv_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// order = 1
B FFTEnd
orderGreaterthan1:
MOV tmpOrder,order @// tmpOrder = RN 4
BL armSP_FFTInv_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe
CMP tmpOrder,#2
BLGT armSP_FFTInv_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe
BL armSP_FFTInv_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe
B FFTEnd
orderGreaterthan3:
@// check scale = 0 or scale = order
SUBS diff, scale, order @// scale > order
MOVGT scale,order
BGE specialScaleCase @// scale = 0 or scale = order
CMP scale,#0
BEQ specialScaleCase
B generalScaleCase
specialScaleCase: @// scale = 0 or scale = order and order >= 2
TST order, #2 @// Set input args to fft stages
MOVNE argDst,pDst
MOVEQ argDst,pOut
MOVEQ pOut,pDst @// Pass the first stage destination in RN5
MOV argTwiddle,pTwiddle
CMP diff,#0
M_STR diff, diffOnStack
BGE scaleEqualsOrder
@//check for even or odd order
@// NOTE: The following combination of BL's would work fine eventhough the first
@// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside
@// armSP_FFTInv_CToC_SC32_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ
TST order,#0x00000001
BLEQ armSP_FFTInv_CToC_SC32_Radix4_fs_OutOfPlace_unsafe
BLNE armSP_FFTInv_CToC_SC32_Radix8_fs_OutOfPlace_unsafe
CMP subFFTNum,#4
BLT FFTEnd
unscaledRadix4Loop:
BEQ lastStageUnscaledRadix4
BL armSP_FFTInv_CToC_SC32_Radix4_OutOfPlace_unsafe
CMP subFFTNum,#4
B unscaledRadix4Loop
lastStageUnscaledRadix4:
BL armSP_FFTInv_CToC_SC32_Radix4_ls_OutOfPlace_unsafe
B FFTEnd
scaleEqualsOrder:
@//check for even or odd order
@// NOTE: The following combination of BL's would work fine eventhough the first
@// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside
@// armSP_FFTInv_CToC_SC32_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ
TST order,#0x00000001
BLEQ armSP_FFTInv_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe
BLNE armSP_FFTInv_CToC_SC32_Sfs_Radix8_fs_OutOfPlace_unsafe
CMP subFFTNum,#4
BLT FFTEnd
scaledRadix4Loop:
BEQ lastStageScaledRadix4
BL armSP_FFTInv_CToC_SC32_Sfs_Radix4_OutOfPlace_unsafe
CMP subFFTNum,#4
B scaledRadix4Loop
lastStageScaledRadix4:
BL armSP_FFTInv_CToC_SC32_Sfs_Radix4_ls_OutOfPlace_unsafe
B FFTEnd
generalScaleCase: @// 0 < scale < order and order >= 2
@// Determine the correct destination buffer
SUB diff,order,scale
TST diff,#0x01
ADDEQ count,scale,diff,LSR #1 @// count = scale + (order - scale)/2
MOVNE count,order
TST count,#0x01 @// Is count even or odd ?
MOVNE argDst,pDst @// Set input args to fft stages
MOVEQ argDst,pOut
MOVEQ pOut,pDst @// Pass the first stage destination in RN5
MOV argTwiddle,pTwiddle
M_STR diff, diffOnStack
MOV argScale,scale @// Put scale in RN4 so as to save and restore
BL armSP_FFTInv_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// scaled first stage
SUBS argScale,argScale,#1
scaledRadix2Loop:
BLGT armSP_FFTInv_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe
SUBS argScale,argScale,#1 @// save and restore scale (RN4) in the scaled stages
BGT scaledRadix2Loop
M_LDR diff, diffOnStack
@//check for even or odd order
TST diff,#0x00000001
BEQ generalUnscaledRadix4Loop
B unscaledRadix2Loop
generalUnscaledRadix4Loop:
CMP subFFTNum,#4
BEQ generalLastStageUnscaledRadix4
BL armSP_FFTInv_CToC_SC32_Radix4_OutOfPlace_unsafe
B generalUnscaledRadix4Loop
generalLastStageUnscaledRadix4:
BL armSP_FFTInv_CToC_SC32_Radix4_ls_OutOfPlace_unsafe
B End
unscaledRadix2Loop:
CMP subFFTNum,#2
BEQ generalLastStageUnscaledRadix2
BL armSP_FFTInv_CToC_SC32_Radix2_OutOfPlace_unsafe
B unscaledRadix2Loop
generalLastStageUnscaledRadix2:
BL armSP_FFTInv_CToC_SC32_Radix2_ls_OutOfPlace_unsafe
B End
FFTEnd: @// Does only the scaling
M_LDR diff, diffOnStack
CMP diff,#0
BLE End
RSB diff,diff,#0 @// to use VRSHL for right shift by a variable
VDUP dShift,diff
scaleFFTData: @// N = subFFTSize ; dataptr = pDst ; scale = diff
VLD1 {dX0},[pSrc] @// pSrc contains pDst pointer
SUBS subFFTSize,subFFTSize,#1
VRSHL dX0,dShift
VST1 {dX0},[pSrc]!
BGT scaleFFTData
End:
@// Set return value
MOV result, #OMX_Sts_NoErr
@// Write function tail
M_END
.end
|