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  1. /*
  2. * Copyright (c) 2013 RISC OS Open Ltd
  3. * Author: Ben Avison <bavison@riscosopen.org>
  4. *
  5. * This file is part of Libav.
  6. *
  7. * Libav is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU Lesser General Public
  9. * License as published by the Free Software Foundation; either
  10. * version 2.1 of the License, or (at your option) any later version.
  11. *
  12. * Libav is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15. * Lesser General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU Lesser General Public
  18. * License along with Libav; if not, write to the Free Software
  19. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20. */
  21. #include "libavutil/arm/asm.S"
  22. @ The fftx_internal_vfp versions of the functions obey a modified AAPCS:
  23. @ VFP is in RunFast mode, vector length 4, stride 1 thoroughout, and
  24. @ all single-precision VFP registers may be corrupted on exit. The a2
  25. @ register may not be clobbered in these functions, as it holds the
  26. @ stored original FPSCR.
  27. function ff_fft_calc_vfp, export=1
  28. ldr ip, [a1, #0] @ nbits
  29. mov a1, a2
  30. A ldr pc, [pc, ip, lsl #2]
  31. A .word 0
  32. A .word 0
  33. A .word 0
  34. T movrel a2, (fft_tab_vfp - 8)
  35. T ldr pc, [a2, ip, lsl #2]
  36. T endfunc
  37. T const fft_tab_vfp
  38. .word fft4_vfp
  39. .word fft8_vfp
  40. .word X(ff_fft16_vfp) @ this one alone is exported
  41. .word fft32_vfp
  42. .word fft64_vfp
  43. .word fft128_vfp
  44. .word fft256_vfp
  45. .word fft512_vfp
  46. .word fft1024_vfp
  47. .word fft2048_vfp
  48. .word fft4096_vfp
  49. .word fft8192_vfp
  50. .word fft16384_vfp
  51. .word fft32768_vfp
  52. .word fft65536_vfp
  53. A endfunc
  54. function fft4_vfp
  55. vldr d0, [a1, #0*2*4] @ s0,s1 = z[0]
  56. vldr d4, [a1, #1*2*4] @ s8,s9 = z[1]
  57. vldr d1, [a1, #2*2*4] @ s2,s3 = z[2]
  58. vldr d5, [a1, #3*2*4] @ s10,s11 = z[3]
  59. @ stall
  60. vadd.f s12, s0, s8 @ i0
  61. vadd.f s13, s1, s9 @ i1
  62. vadd.f s14, s2, s10 @ i2
  63. vadd.f s15, s3, s11 @ i3
  64. vsub.f s8, s0, s8 @ i4
  65. vsub.f s9, s1, s9 @ i5
  66. vsub.f s10, s2, s10 @ i6
  67. vsub.f s11, s3, s11 @ i7
  68. @ stall
  69. @ stall
  70. vadd.f s0, s12, s14 @ z[0].re
  71. vsub.f s4, s12, s14 @ z[2].re
  72. vadd.f s1, s13, s15 @ z[0].im
  73. vsub.f s5, s13, s15 @ z[2].im
  74. vadd.f s7, s9, s10 @ z[3].im
  75. vsub.f s3, s9, s10 @ z[1].im
  76. vadd.f s2, s8, s11 @ z[1].re
  77. vsub.f s6, s8, s11 @ z[3].re
  78. @ stall
  79. @ stall
  80. vstr d0, [a1, #0*2*4]
  81. vstr d2, [a1, #2*2*4]
  82. @ stall
  83. @ stall
  84. vstr d1, [a1, #1*2*4]
  85. vstr d3, [a1, #3*2*4]
  86. bx lr
  87. endfunc
  88. .macro macro_fft8_head
  89. @ FFT4
  90. vldr d4, [a1, #0 * 2*4]
  91. vldr d6, [a1, #1 * 2*4]
  92. vldr d5, [a1, #2 * 2*4]
  93. vldr d7, [a1, #3 * 2*4]
  94. @ BF
  95. vldr d12, [a1, #4 * 2*4]
  96. vadd.f s16, s8, s12 @ vector op
  97. vldr d14, [a1, #5 * 2*4]
  98. vldr d13, [a1, #6 * 2*4]
  99. vldr d15, [a1, #7 * 2*4]
  100. vsub.f s20, s8, s12 @ vector op
  101. vadd.f s0, s16, s18
  102. vsub.f s2, s16, s18
  103. vadd.f s1, s17, s19
  104. vsub.f s3, s17, s19
  105. vadd.f s7, s21, s22
  106. vsub.f s5, s21, s22
  107. vadd.f s4, s20, s23
  108. vsub.f s6, s20, s23
  109. vsub.f s20, s24, s28 @ vector op
  110. vstr d0, [a1, #0 * 2*4] @ transfer s0-s7 to s24-s31 via memory
  111. vstr d1, [a1, #1 * 2*4]
  112. vldr s0, cos1pi4
  113. vadd.f s16, s24, s28 @ vector op
  114. vstr d2, [a1, #2 * 2*4]
  115. vstr d3, [a1, #3 * 2*4]
  116. vldr d12, [a1, #0 * 2*4]
  117. @ TRANSFORM
  118. vmul.f s20, s20, s0 @ vector x scalar op
  119. vldr d13, [a1, #1 * 2*4]
  120. vldr d14, [a1, #2 * 2*4]
  121. vldr d15, [a1, #3 * 2*4]
  122. @ BUTTERFLIES
  123. vadd.f s0, s18, s16
  124. vadd.f s1, s17, s19
  125. vsub.f s2, s17, s19
  126. vsub.f s3, s18, s16
  127. vadd.f s4, s21, s20
  128. vsub.f s5, s21, s20
  129. vadd.f s6, s22, s23
  130. vsub.f s7, s22, s23
  131. vadd.f s8, s0, s24 @ vector op
  132. vstr d0, [a1, #0 * 2*4] @ transfer s0-s3 to s12-s15 via memory
  133. vstr d1, [a1, #1 * 2*4]
  134. vldr d6, [a1, #0 * 2*4]
  135. vldr d7, [a1, #1 * 2*4]
  136. vadd.f s1, s5, s6
  137. vadd.f s0, s7, s4
  138. vsub.f s2, s5, s6
  139. vsub.f s3, s7, s4
  140. vsub.f s12, s24, s12 @ vector op
  141. vsub.f s5, s29, s1
  142. vsub.f s4, s28, s0
  143. vsub.f s6, s30, s2
  144. vsub.f s7, s31, s3
  145. vadd.f s16, s0, s28 @ vector op
  146. vstr d6, [a1, #4 * 2*4]
  147. vstr d7, [a1, #6 * 2*4]
  148. vstr d4, [a1, #0 * 2*4]
  149. vstr d5, [a1, #2 * 2*4]
  150. vstr d2, [a1, #5 * 2*4]
  151. vstr d3, [a1, #7 * 2*4]
  152. .endm
  153. .macro macro_fft8_tail
  154. vstr d8, [a1, #1 * 2*4]
  155. vstr d9, [a1, #3 * 2*4]
  156. .endm
  157. function .Lfft8_internal_vfp
  158. macro_fft8_head
  159. macro_fft8_tail
  160. bx lr
  161. endfunc
  162. function fft8_vfp
  163. ldr a3, =0x03030000 @ RunFast mode, vector length 4, stride 1
  164. fmrx a2, FPSCR
  165. fmxr FPSCR, a3
  166. vpush {s16-s31}
  167. mov ip, lr
  168. bl .Lfft8_internal_vfp
  169. vpop {s16-s31}
  170. fmxr FPSCR, a2
  171. bx ip
  172. endfunc
  173. .align 3
  174. cos1pi4: @ cos(1*pi/4) = sqrt(2)
  175. .float 0.707106769084930419921875
  176. cos1pi8: @ cos(1*pi/8) = sqrt(2+sqrt(2))/2
  177. .float 0.92387950420379638671875
  178. cos3pi8: @ cos(2*pi/8) = sqrt(2-sqrt(2))/2
  179. .float 0.3826834261417388916015625
  180. function .Lfft16_internal_vfp
  181. macro_fft8_head
  182. @ FFT4(z+8)
  183. vldr d10, [a1, #8 * 2*4]
  184. vldr d12, [a1, #9 * 2*4]
  185. vldr d11, [a1, #10 * 2*4]
  186. vldr d13, [a1, #11 * 2*4]
  187. macro_fft8_tail
  188. vadd.f s16, s20, s24 @ vector op
  189. @ FFT4(z+12)
  190. vldr d4, [a1, #12 * 2*4]
  191. vldr d6, [a1, #13 * 2*4]
  192. vldr d5, [a1, #14 * 2*4]
  193. vsub.f s20, s20, s24 @ vector op
  194. vldr d7, [a1, #15 * 2*4]
  195. vadd.f s0, s16, s18
  196. vsub.f s4, s16, s18
  197. vadd.f s1, s17, s19
  198. vsub.f s5, s17, s19
  199. vadd.f s7, s21, s22
  200. vsub.f s3, s21, s22
  201. vadd.f s2, s20, s23
  202. vsub.f s6, s20, s23
  203. vadd.f s16, s8, s12 @ vector op
  204. vstr d0, [a1, #8 * 2*4]
  205. vstr d2, [a1, #10 * 2*4]
  206. vstr d1, [a1, #9 * 2*4]
  207. vsub.f s20, s8, s12
  208. vstr d3, [a1, #11 * 2*4]
  209. @ TRANSFORM(z[2],z[6],z[10],z[14],cos1pi4,cos1pi4)
  210. vldr d12, [a1, #10 * 2*4]
  211. vadd.f s0, s16, s18
  212. vadd.f s1, s17, s19
  213. vsub.f s6, s16, s18
  214. vsub.f s7, s17, s19
  215. vsub.f s3, s21, s22
  216. vadd.f s2, s20, s23
  217. vadd.f s5, s21, s22
  218. vsub.f s4, s20, s23
  219. vstr d0, [a1, #12 * 2*4]
  220. vmov s0, s6
  221. @ TRANSFORM(z[1],z[5],z[9],z[13],cos1pi8,cos3pi8)
  222. vldr d6, [a1, #9 * 2*4]
  223. vstr d1, [a1, #13 * 2*4]
  224. vldr d1, cos1pi4 @ s2 = cos1pi4, s3 = cos1pi8
  225. vstr d2, [a1, #15 * 2*4]
  226. vldr d7, [a1, #13 * 2*4]
  227. vadd.f s4, s25, s24
  228. vsub.f s5, s25, s24
  229. vsub.f s6, s0, s7
  230. vadd.f s7, s0, s7
  231. vmul.f s20, s12, s3 @ vector op
  232. @ TRANSFORM(z[3],z[7],z[11],z[15],cos3pi8,cos1pi8)
  233. vldr d4, [a1, #11 * 2*4]
  234. vldr d5, [a1, #15 * 2*4]
  235. vldr s1, cos3pi8
  236. vmul.f s24, s4, s2 @ vector * scalar op
  237. vmul.f s28, s12, s1 @ vector * scalar op
  238. vmul.f s12, s8, s1 @ vector * scalar op
  239. vadd.f s4, s20, s29
  240. vsub.f s5, s21, s28
  241. vsub.f s6, s22, s31
  242. vadd.f s7, s23, s30
  243. vmul.f s8, s8, s3 @ vector * scalar op
  244. vldr d8, [a1, #1 * 2*4]
  245. vldr d9, [a1, #5 * 2*4]
  246. vldr d10, [a1, #3 * 2*4]
  247. vldr d11, [a1, #7 * 2*4]
  248. vldr d14, [a1, #2 * 2*4]
  249. vadd.f s0, s6, s4
  250. vadd.f s1, s5, s7
  251. vsub.f s2, s5, s7
  252. vsub.f s3, s6, s4
  253. vadd.f s4, s12, s9
  254. vsub.f s5, s13, s8
  255. vsub.f s6, s14, s11
  256. vadd.f s7, s15, s10
  257. vadd.f s12, s0, s16 @ vector op
  258. vstr d0, [a1, #1 * 2*4]
  259. vstr d1, [a1, #5 * 2*4]
  260. vldr d4, [a1, #1 * 2*4]
  261. vldr d5, [a1, #5 * 2*4]
  262. vadd.f s0, s6, s4
  263. vadd.f s1, s5, s7
  264. vsub.f s2, s5, s7
  265. vsub.f s3, s6, s4
  266. vsub.f s8, s16, s8 @ vector op
  267. vstr d6, [a1, #1 * 2*4]
  268. vstr d7, [a1, #5 * 2*4]
  269. vldr d15, [a1, #6 * 2*4]
  270. vsub.f s4, s20, s0
  271. vsub.f s5, s21, s1
  272. vsub.f s6, s22, s2
  273. vsub.f s7, s23, s3
  274. vadd.f s20, s0, s20 @ vector op
  275. vstr d4, [a1, #9 * 2*4]
  276. @ TRANSFORM_ZERO(z[0],z[4],z[8],z[12])
  277. vldr d6, [a1, #8 * 2*4]
  278. vstr d5, [a1, #13 * 2*4]
  279. vldr d7, [a1, #12 * 2*4]
  280. vstr d2, [a1, #11 * 2*4]
  281. vldr d8, [a1, #0 * 2*4]
  282. vstr d3, [a1, #15 * 2*4]
  283. vldr d9, [a1, #4 * 2*4]
  284. vadd.f s0, s26, s24
  285. vadd.f s1, s25, s27
  286. vsub.f s2, s25, s27
  287. vsub.f s3, s26, s24
  288. vadd.f s4, s14, s12
  289. vadd.f s5, s13, s15
  290. vsub.f s6, s13, s15
  291. vsub.f s7, s14, s12
  292. vadd.f s8, s0, s28 @ vector op
  293. vstr d0, [a1, #3 * 2*4]
  294. vstr d1, [a1, #7 * 2*4]
  295. vldr d6, [a1, #3 * 2*4]
  296. vldr d7, [a1, #7 * 2*4]
  297. vsub.f s0, s16, s4
  298. vsub.f s1, s17, s5
  299. vsub.f s2, s18, s6
  300. vsub.f s3, s19, s7
  301. vsub.f s12, s28, s12 @ vector op
  302. vadd.f s16, s4, s16 @ vector op
  303. vstr d10, [a1, #3 * 2*4]
  304. vstr d11, [a1, #7 * 2*4]
  305. vstr d4, [a1, #2 * 2*4]
  306. vstr d5, [a1, #6 * 2*4]
  307. vstr d0, [a1, #8 * 2*4]
  308. vstr d1, [a1, #12 * 2*4]
  309. vstr d6, [a1, #10 * 2*4]
  310. vstr d7, [a1, #14 * 2*4]
  311. vstr d8, [a1, #0 * 2*4]
  312. vstr d9, [a1, #4 * 2*4]
  313. bx lr
  314. endfunc
  315. function ff_fft16_vfp, export=1
  316. ldr a3, =0x03030000 @ RunFast mode, vector length 4, stride 1
  317. fmrx a2, FPSCR
  318. fmxr FPSCR, a3
  319. vpush {s16-s31}
  320. mov ip, lr
  321. bl .Lfft16_internal_vfp
  322. vpop {s16-s31}
  323. fmxr FPSCR, a2
  324. bx ip
  325. endfunc
  326. .macro pass n, z0, z1, z2, z3
  327. add v6, v5, #4*2*\n
  328. @ TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3])
  329. @ TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1])
  330. @ TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0])
  331. @ TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1])
  332. vldr d8, [\z2, #8*(o2+1)] @ s16,s17
  333. vldmdb v6!, {s2}
  334. vldr d9, [\z3, #8*(o3+1)] @ s18,s19
  335. vldmia v5!, {s0,s1} @ s0 is unused
  336. vldr s7, [\z2, #8*o2] @ t1
  337. vmul.f s20, s16, s2 @ vector * scalar
  338. vldr s0, [\z3, #8*o3] @ t5
  339. vldr s6, [\z2, #8*o2+4] @ t2
  340. vldr s3, [\z3, #8*o3+4] @ t6
  341. vmul.f s16, s16, s1 @ vector * scalar
  342. ldr a4, =\n-1
  343. 1: add \z0, \z0, #8*2
  344. .if \n*4*2 >= 512
  345. add \z1, \z1, #8*2
  346. .endif
  347. .if \n*4*2 >= 256
  348. add \z2, \z2, #8*2
  349. .endif
  350. .if \n*4*2 >= 512
  351. add \z3, \z3, #8*2
  352. .endif
  353. @ up to 2 stalls (VFP vector issuing / waiting for s0)
  354. @ depending upon whether this is the first iteration and
  355. @ how many add instructions are inserted above
  356. vadd.f s4, s0, s7 @ t5
  357. vadd.f s5, s6, s3 @ t6
  358. vsub.f s6, s6, s3 @ t4
  359. vsub.f s7, s0, s7 @ t3
  360. vldr d6, [\z0, #8*0-8*2] @ s12,s13
  361. vadd.f s0, s16, s21 @ t1
  362. vldr d7, [\z1, #8*o1-8*2] @ s14,s15
  363. vsub.f s1, s18, s23 @ t5
  364. vadd.f s8, s4, s12 @ vector + vector
  365. @ stall (VFP vector issuing)
  366. @ stall (VFP vector issuing)
  367. @ stall (VFP vector issuing)
  368. vsub.f s4, s12, s4
  369. vsub.f s5, s13, s5
  370. vsub.f s6, s14, s6
  371. vsub.f s7, s15, s7
  372. vsub.f s2, s17, s20 @ t2
  373. vadd.f s3, s19, s22 @ t6
  374. vstr d4, [\z0, #8*0-8*2] @ s8,s9
  375. vstr d5, [\z1, #8*o1-8*2] @ s10,s11
  376. @ stall (waiting for s5)
  377. vstr d2, [\z2, #8*o2-8*2] @ s4,s5
  378. vadd.f s4, s1, s0 @ t5
  379. vstr d3, [\z3, #8*o3-8*2] @ s6,s7
  380. vsub.f s7, s1, s0 @ t3
  381. vadd.f s5, s2, s3 @ t6
  382. vsub.f s6, s2, s3 @ t4
  383. vldr d6, [\z0, #8*1-8*2] @ s12,s13
  384. vldr d7, [\z1, #8*(o1+1)-8*2] @ s14,s15
  385. vldr d4, [\z2, #8*o2] @ s8,s9
  386. vldmdb v6!, {s2,s3}
  387. vldr d5, [\z3, #8*o3] @ s10,s11
  388. vadd.f s20, s4, s12 @ vector + vector
  389. vldmia v5!, {s0,s1}
  390. vldr d8, [\z2, #8*(o2+1)] @ s16,s17
  391. @ stall (VFP vector issuing)
  392. vsub.f s4, s12, s4
  393. vsub.f s5, s13, s5
  394. vsub.f s6, s14, s6
  395. vsub.f s7, s15, s7
  396. vmul.f s12, s8, s3 @ vector * scalar
  397. vstr d10, [\z0, #8*1-8*2] @ s20,s21
  398. vldr d9, [\z3, #8*(o3+1)] @ s18,s19
  399. vstr d11, [\z1, #8*(o1+1)-8*2] @ s22,s23
  400. vmul.f s8, s8, s0 @ vector * scalar
  401. vstr d2, [\z2, #8*(o2+1)-8*2] @ s4,s5
  402. @ stall (waiting for s7)
  403. vstr d3, [\z3, #8*(o3+1)-8*2] @ s6,s7
  404. vmul.f s20, s16, s2 @ vector * scalar
  405. @ stall (VFP vector issuing)
  406. @ stall (VFP vector issuing)
  407. @ stall (VFP vector issuing)
  408. vadd.f s7, s8, s13 @ t1
  409. vsub.f s6, s9, s12 @ t2
  410. vsub.f s0, s10, s15 @ t5
  411. vadd.f s3, s11, s14 @ t6
  412. vmul.f s16, s16, s1 @ vector * scalar
  413. subs a4, a4, #1
  414. bne 1b
  415. @ What remains is identical to the first two indentations of
  416. @ the above, but without the increment of z
  417. vadd.f s4, s0, s7 @ t5
  418. vadd.f s5, s6, s3 @ t6
  419. vsub.f s6, s6, s3 @ t4
  420. vsub.f s7, s0, s7 @ t3
  421. vldr d6, [\z0, #8*0] @ s12,s13
  422. vadd.f s0, s16, s21 @ t1
  423. vldr d7, [\z1, #8*o1] @ s14,s15
  424. vsub.f s1, s18, s23 @ t5
  425. vadd.f s8, s4, s12 @ vector + vector
  426. vsub.f s4, s12, s4
  427. vsub.f s5, s13, s5
  428. vsub.f s6, s14, s6
  429. vsub.f s7, s15, s7
  430. vsub.f s2, s17, s20 @ t2
  431. vadd.f s3, s19, s22 @ t6
  432. vstr d4, [\z0, #8*0] @ s8,s9
  433. vstr d5, [\z1, #8*o1] @ s10,s11
  434. vstr d2, [\z2, #8*o2] @ s4,s5
  435. vadd.f s4, s1, s0 @ t5
  436. vstr d3, [\z3, #8*o3] @ s6,s7
  437. vsub.f s7, s1, s0 @ t3
  438. vadd.f s5, s2, s3 @ t6
  439. vsub.f s6, s2, s3 @ t4
  440. vldr d6, [\z0, #8*1] @ s12,s13
  441. vldr d7, [\z1, #8*(o1+1)] @ s14,s15
  442. vadd.f s20, s4, s12 @ vector + vector
  443. vsub.f s4, s12, s4
  444. vsub.f s5, s13, s5
  445. vsub.f s6, s14, s6
  446. vsub.f s7, s15, s7
  447. vstr d10, [\z0, #8*1] @ s20,s21
  448. vstr d11, [\z1, #8*(o1+1)] @ s22,s23
  449. vstr d2, [\z2, #8*(o2+1)] @ s4,s5
  450. vstr d3, [\z3, #8*(o3+1)] @ s6,s7
  451. .endm
  452. .macro def_fft n, n2, n4
  453. function .Lfft\n\()_internal_vfp
  454. .if \n >= 512
  455. push {v1-v6,lr}
  456. .elseif \n >= 256
  457. push {v1-v2,v5-v6,lr}
  458. .else
  459. push {v1,v5-v6,lr}
  460. .endif
  461. mov v1, a1
  462. bl .Lfft\n2\()_internal_vfp
  463. add a1, v1, #8*(\n/4)*2
  464. bl .Lfft\n4\()_internal_vfp
  465. movrelx v5, X(ff_cos_\n), a1
  466. add a1, v1, #8*(\n/4)*3
  467. bl .Lfft\n4\()_internal_vfp
  468. .if \n >= 512
  469. .set o1, 0*(\n/4/2)
  470. .set o2, 0*(\n/4/2)
  471. .set o3, 0*(\n/4/2)
  472. add v2, v1, #8*2*(\n/4/2)
  473. add v3, v1, #8*4*(\n/4/2)
  474. add v4, v1, #8*6*(\n/4/2)
  475. pass (\n/4/2), v1, v2, v3, v4
  476. pop {v1-v6,pc}
  477. .elseif \n >= 256
  478. .set o1, 2*(\n/4/2)
  479. .set o2, 0*(\n/4/2)
  480. .set o3, 2*(\n/4/2)
  481. add v2, v1, #8*4*(\n/4/2)
  482. pass (\n/4/2), v1, v1, v2, v2
  483. pop {v1-v2,v5-v6,pc}
  484. .else
  485. .set o1, 2*(\n/4/2)
  486. .set o2, 4*(\n/4/2)
  487. .set o3, 6*(\n/4/2)
  488. pass (\n/4/2), v1, v1, v1, v1
  489. pop {v1,v5-v6,pc}
  490. .endif
  491. endfunc
  492. function fft\n\()_vfp
  493. ldr a3, =0x03030000 /* RunFast mode, vector length 4, stride 1 */
  494. fmrx a2, FPSCR
  495. fmxr FPSCR, a3
  496. vpush {s16-s31}
  497. mov ip, lr
  498. bl .Lfft\n\()_internal_vfp
  499. vpop {s16-s31}
  500. fmxr FPSCR, a2
  501. bx ip
  502. endfunc
  503. .ltorg
  504. .endm
  505. def_fft 32, 16, 8
  506. def_fft 64, 32, 16
  507. def_fft 128, 64, 32
  508. def_fft 256, 128, 64
  509. def_fft 512, 256, 128
  510. def_fft 1024, 512, 256
  511. def_fft 2048, 1024, 512
  512. def_fft 4096, 2048, 1024
  513. def_fft 8192, 4096, 2048
  514. def_fft 16384, 8192, 4096
  515. def_fft 32768, 16384, 8192
  516. def_fft 65536, 32768, 16384