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      1 @ Tremolo library
      2 @-----------------------------------------------------------------------
      3 @ Copyright (C) 2002-2009, Xiph.org Foundation
      4 @ Copyright (C) 2010, Robin Watts for Pinknoise Productions Ltd
      5 @ All rights reserved.
      6 
      7 @ Redistribution and use in source and binary forms, with or without
      8 @ modification, are permitted provided that the following conditions
      9 @ are met:
     10 
     11 @     * Redistributions of source code must retain the above copyright
     12 @ notice, this list of conditions and the following disclaimer.
     13 @     * Redistributions in binary form must reproduce the above
     14 @ copyright notice, this list of conditions and the following disclaimer
     15 @ in the documentation and/or other materials provided with the
     16 @ distribution.
     17 @     * Neither the names of the Xiph.org Foundation nor Pinknoise
     18 @ Productions Ltd nor the names of its contributors may be used to
     19 @ endorse or promote products derived from this software without
     20 @ specific prior written permission.
     21 @
     22 @ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     23 @ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     24 @ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     25 @ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     26 @ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     27 @ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     28 @ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     29 @ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     30 @ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     31 @ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     32 @ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33 @ ----------------------------------------------------------------------
     34 
     35     .text
     36 
     37 	@ full accuracy version
     38 
     39 	.global mdct_backwardARM
     40 	.global mdct_shift_right
     41 	.global mdct_unroll_prelap
     42 	.global mdct_unroll_part2
     43 	.global mdct_unroll_part3
     44 	.global mdct_unroll_postlap
     45 
     46 	.extern	sincos_lookup0
     47 	.extern	sincos_lookup1
     48 	.hidden	sincos_lookup0
     49 	.hidden	sincos_lookup1
     50 
     51 mdct_unroll_prelap:
     52 	@ r0 = out
     53 	@ r1 = post
     54 	@ r2 = r
     55 	@ r3 = step
     56 	STMFD	r13!,{r4-r7,r14}
     57 	MVN	r4, #0x8000
     58 	MOV	r3, r3, LSL #1
     59 	SUB	r1, r2, r1		@ r1 = r - post
     60 	SUBS	r1, r1, #16		@ r1 = r - post - 16
     61 	BLT	unroll_over
     62 unroll_loop:
     63 	LDMDB	r2!,{r5,r6,r7,r12}
     64 
     65 	MOV	r5, r5, ASR #9		@ r5 = (*--r)>>9
     66 	MOV	r6, r6, ASR #9		@ r6 = (*--r)>>9
     67 	MOV	r7, r7, ASR #9		@ r7 = (*--r)>>9
     68 	MOV	r12,r12,ASR #9		@ r12= (*--r)>>9
     69 
     70 	MOV	r14,r12,ASR #15
     71 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
     72 	EORNE	r12,r4, r14,ASR #31
     73 	STRH	r12,[r0], r3
     74 
     75 	MOV	r14,r7, ASR #15
     76 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
     77 	EORNE	r7, r4, r14,ASR #31
     78 	STRH	r7, [r0], r3
     79 
     80 	MOV	r14,r6, ASR #15
     81 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
     82 	EORNE	r6, r4, r14,ASR #31
     83 	STRH	r6, [r0], r3
     84 
     85 	MOV	r14,r5, ASR #15
     86 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
     87 	EORNE	r5, r4, r14,ASR #31
     88 	STRH	r5, [r0], r3
     89 
     90 	SUBS	r1, r1, #16
     91 	BGE	unroll_loop
     92 
     93 unroll_over:
     94 	ADDS	r1, r1, #16
     95 	BLE	unroll_end
     96 unroll_loop2:
     97 	LDR	r5,[r2,#-4]!
     98 	@ stall
     99 	@ stall (Xscale)
    100 	MOV	r5, r5, ASR #9		@ r5 = (*--r)>>9
    101 	MOV	r14,r5, ASR #15
    102 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    103 	EORNE	r5, r4, r14,ASR #31
    104 	STRH	r5, [r0], r3
    105 	SUBS	r1, r1, #4
    106 	BGT	unroll_loop2
    107 unroll_end:
    108 	LDMFD	r13!,{r4-r7,PC}
    109 
    110 mdct_unroll_postlap:
    111 	@ r0 = out
    112 	@ r1 = post
    113 	@ r2 = l
    114 	@ r3 = step
    115 	STMFD	r13!,{r4-r7,r14}
    116 	MVN	r4, #0x8000
    117 	MOV	r3, r3, LSL #1
    118 	SUB	r1, r1, r2		@ r1 = post - l
    119 	MOV	r1, r1, ASR #1		@ r1 = (post - l)>>1
    120 	SUBS	r1, r1, #16		@ r1 = ((post - l)>>1) - 4
    121 	BLT	unroll_over3
    122 unroll_loop3:
    123 	LDR	r12,[r2],#8
    124 	LDR	r7, [r2],#8
    125 	LDR	r6, [r2],#8
    126 	LDR	r5, [r2],#8
    127 
    128 	RSB	r12,r12,#0
    129 	RSB	r5, r5, #0
    130 	RSB	r6, r6, #0
    131 	RSB	r7, r7, #0
    132 
    133 	MOV	r12, r12,ASR #9		@ r12= (-*l)>>9
    134 	MOV	r5,  r5, ASR #9		@ r5 = (-*l)>>9
    135 	MOV	r6,  r6, ASR #9		@ r6 = (-*l)>>9
    136 	MOV	r7,  r7, ASR #9		@ r7 = (-*l)>>9
    137 
    138 	MOV	r14,r12,ASR #15
    139 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    140 	EORNE	r12,r4, r14,ASR #31
    141 	STRH	r12,[r0], r3
    142 
    143 	MOV	r14,r7, ASR #15
    144 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    145 	EORNE	r7, r4, r14,ASR #31
    146 	STRH	r7, [r0], r3
    147 
    148 	MOV	r14,r6, ASR #15
    149 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    150 	EORNE	r6, r4, r14,ASR #31
    151 	STRH	r6, [r0], r3
    152 
    153 	MOV	r14,r5, ASR #15
    154 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    155 	EORNE	r5, r4, r14,ASR #31
    156 	STRH	r5, [r0], r3
    157 
    158 	SUBS	r1, r1, #16
    159 	BGE	unroll_loop3
    160 
    161 unroll_over3:
    162 	ADDS	r1, r1, #16
    163 	BLE	unroll_over4
    164 unroll_loop4:
    165 	LDR	r5,[r2], #8
    166 	@ stall
    167 	@ stall (Xscale)
    168 	RSB	r5, r5, #0
    169 	MOV	r5, r5, ASR #9		@ r5 = (-*l)>>9
    170 	MOV	r14,r5, ASR #15
    171 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    172 	EORNE	r5, r4, r14,ASR #31
    173 	STRH	r5, [r0], r3
    174 	SUBS	r1, r1, #4
    175 	BGT	unroll_loop4
    176 unroll_over4:
    177 	LDMFD	r13!,{r4-r7,PC}
    178 
    179 mdct_unroll_part2:
    180 	@ r0 = out
    181 	@ r1 = post
    182 	@ r2 = l
    183 	@ r3 = r
    184 	@ <> = step
    185 	@ <> = wL
    186 	@ <> = wR
    187 	MOV	r12,r13
    188 	STMFD	r13!,{r4,r6-r11,r14}
    189 	LDMFD	r12,{r8,r9,r10}		@ r8 = step
    190 					@ r9 = wL
    191 					@ r10= wR
    192 	MVN	r4, #0x8000
    193 	MOV	r8, r8, LSL #1
    194 	SUBS	r1, r3, r1		@ r1 = (r - post)
    195 	BLE	unroll_over5
    196 unroll_loop5:
    197 	LDR	r12,[r2, #-8]!		@ r12= *l       (but l -= 2 first)
    198 	LDR	r11,[r9],#4		@ r11= *wL++
    199 	LDR	r7, [r3, #-4]!		@ r7 = *--r
    200 	LDR	r6, [r10,#-4]!		@ r6 = *--wR
    201 
    202 	@ Can save a cycle here, at the cost of 1bit errors in rounding
    203 	SMULL	r14,r11,r12,r11		@ (r14,r11)  = *l   * *wL++
    204 	SMULL	r14,r6, r7, r6		@ (r14,r6)   = *--r * *--wR
    205 	ADD	r6, r6, r11
    206 	MOV	r6, r6, ASR #8
    207 	MOV	r14,r6, ASR #15
    208 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    209 	EORNE	r6, r4, r14,ASR #31
    210 	STRH	r6, [r0], r8
    211 
    212 	SUBS	r1, r1, #4
    213 	BGT	unroll_loop5
    214 
    215 unroll_over5:
    216 	LDMFD	r13!,{r4,r6-r11,PC}
    217 
    218 mdct_unroll_part3:
    219 	@ r0 = out
    220 	@ r1 = post
    221 	@ r2 = l
    222 	@ r3 = r
    223 	@ <> = step
    224 	@ <> = wL
    225 	@ <> = wR
    226 	MOV	r12,r13
    227 	STMFD	r13!,{r4,r6-r11,r14}
    228 	LDMFD	r12,{r8,r9,r10}		@ r8 = step
    229 					@ r9 = wL
    230 					@ r10= wR
    231 	MVN	r4, #0x8000
    232 	MOV	r8, r8, LSL #1
    233 	SUBS	r1, r1, r3		@ r1 = (post - r)
    234 	BLE	unroll_over6
    235 unroll_loop6:
    236 	LDR	r12,[r2],#8		@ r12= *l       (but l += 2 first)
    237 	LDR	r11,[r9],#4		@ r11= *wL++
    238 	LDR	r7, [r3],#4		@ r7 = *r++
    239 	LDR	r6, [r10,#-4]!		@ r6 = *--wR
    240 
    241 	@ Can save a cycle here, at the cost of 1bit errors in rounding
    242 	SMULL	r14,r11,r12,r11		@ (r14,r11)  = *l   * *wL++
    243 	SMULL	r14,r6, r7, r6		@ (r14,r6)   = *--r * *--wR
    244 	SUB	r6, r6, r11
    245 	MOV	r6, r6, ASR #8
    246 	MOV	r14,r6, ASR #15
    247 	TEQ	r14,r14,ASR #31		@ if r14==0 || r14==-1 then in range
    248 	EORNE	r6, r4, r14,ASR #31
    249 	STRH	r6, [r0], r8
    250 
    251 	SUBS	r1, r1, #4
    252 	BGT	unroll_loop6
    253 
    254 unroll_over6:
    255 	LDMFD	r13!,{r4,r6-r11,PC}
    256 
    257 mdct_shift_right:
    258 	@ r0 = n
    259 	@ r1 = in
    260 	@ r2 = right
    261 	STMFD	r13!,{r4-r11,r14}
    262 
    263 	MOV	r0, r0, LSR #2		@ n >>= 2
    264 	ADD	r1, r1, #4
    265 
    266 	SUBS	r0, r0,	#8
    267 	BLT	sr_less_than_8
    268 sr_loop:
    269 	LDR	r3, [r1], #8
    270 	LDR	r4, [r1], #8
    271 	LDR	r5, [r1], #8
    272 	LDR	r6, [r1], #8
    273 	LDR	r7, [r1], #8
    274 	LDR	r8, [r1], #8
    275 	LDR	r12,[r1], #8
    276 	LDR	r14,[r1], #8
    277 	SUBS	r0, r0, #8
    278 	STMIA	r2!,{r3,r4,r5,r6,r7,r8,r12,r14}
    279 	BGE	sr_loop
    280 sr_less_than_8:
    281 	ADDS	r0, r0, #8
    282 	BEQ	sr_end
    283 sr_loop2:
    284 	LDR	r3, [r1], #8
    285 	SUBS	r0, r0, #1
    286 	STR	r3, [r2], #4
    287 	BGT	sr_loop2
    288 sr_end:
    289 	LDMFD	r13!,{r4-r11,PC}
    290 
    291 mdct_backwardARM:
    292 	@ r0 = n
    293 	@ r1 = in
    294 	STMFD	r13!,{r4-r11,r14}
    295 
    296 	MOV	r2,#1<<4	@ r2 = 1<<shift
    297 	MOV	r3,#13-4	@ r3 = 13-shift
    298 find_shift_loop:
    299 	TST	r0,r2		@ if (n & (1<<shift)) == 0
    300 	MOV	r2,r2,LSL #1
    301 	SUBEQ	r3,r3,#1	@ shift--
    302 	BEQ	find_shift_loop
    303 	MOV	r2,#2
    304 	MOV	r2,r2,LSL r3	@ r2 = step = 2<<shift
    305 
    306 	@ presymmetry
    307 	@ r0 = n (a multiple of 4)
    308 	@ r1 = in
    309 	@ r2 = step
    310 	@ r3 = shift
    311 
    312 	ADD	r4, r1, r0, LSL #1	@ r4 = aX = in+(n>>1)
    313 	ADD	r14,r1, r0		@ r14= in+(n>>2)
    314 	SUB	r4, r4, #3*4		@ r4 = aX = in+n2-3
    315 	ADRL	r7, .Lsincos_lookup
    316 	LDR	r5, [r7]		@ r5 = T=sincos_lookup0
    317 	ADD	r5, r7
    318 
    319 presymmetry_loop1:
    320 	LDR	r7, [r4,#8]		@ r6 = s2 = aX[2]
    321 	LDR	r11,[r5,#4]		@ r11= T[1]
    322 	LDR	r6, [r4]		@ r6 = s0 = aX[0]
    323 	LDR	r10,[r5],r2,LSL #2	@ r10= T[0]   T += step
    324 
    325 	@ XPROD31(s0, s2, T[0], T[1], 0xaX[0], &ax[2])
    326 	SMULL	r8, r9, r7, r11		@ (r8, r9)   = s2*T[1]
    327 	@ stall
    328 	@ stall ?
    329 	SMLAL	r8, r9, r6, r10		@ (r8, r9)  += s0*T[0]
    330 	RSB	r6, r6, #0
    331 	@ stall ?
    332 	SMULL	r8, r12,r7, r10		@ (r8, r12)  = s2*T[0]
    333 	MOV	r9, r9, LSL #1
    334 	@ stall ?
    335 	SMLAL	r8, r12,r6, r11		@ (r8, r12) -= s0*T[1]
    336 	STR	r9, [r4],#-16		@ aX[0] = r9
    337 	CMP	r4,r14
    338 	MOV	r12,r12,LSL #1
    339 	STR	r12,[r4,#8+16]		@ aX[2] = r12
    340 
    341 	BGE	presymmetry_loop1	@ while (aX >= in+n4)
    342 
    343 presymmetry_loop2:
    344 	LDR	r6,[r4]			@ r6 = s0 = aX[0]
    345 	LDR	r10,[r5,#4]		@ r10= T[1]
    346 	LDR	r7,[r4,#8]		@ r6 = s2 = aX[2]
    347 	LDR	r11,[r5],-r2,LSL #2	@ r11= T[0]   T -= step
    348 
    349 	@ XPROD31(s0, s2, T[1], T[0], 0xaX[0], &ax[2])
    350 	SMULL	r8, r9, r6, r10		@ (r8, r9)   = s0*T[1]
    351 	@ stall
    352 	@ stall ?
    353 	SMLAL	r8, r9, r7, r11		@ (r8, r9)  += s2*T[0]
    354 	RSB	r6, r6, #0
    355 	@ stall ?
    356 	SMULL	r8, r12,r7, r10		@ (r8, r12)  = s2*T[1]
    357 	MOV	r9, r9, LSL #1
    358 	@ stall ?
    359 	SMLAL	r8, r12,r6, r11		@ (r8, r12) -= s0*T[0]
    360 	STR	r9, [r4],#-16		@ aX[0] = r9
    361 	CMP	r4,r1
    362 	MOV	r12,r12,LSL #1
    363 	STR	r12,[r4,#8+16]		@ aX[2] = r12
    364 
    365 	BGE	presymmetry_loop2	@ while (aX >= in)
    366 
    367 	@ r0 = n
    368 	@ r1 = in
    369 	@ r2 = step
    370 	@ r3 = shift
    371 	STMFD	r13!,{r3}
    372 	ADRL	r4, .Lsincos_lookup
    373 	LDR	r5, [r4]		@ r5 = T=sincos_lookup0
    374 	ADD	r5, r4
    375 	ADD	r4, r1, r0, LSL #1	@ r4 = aX = in+(n>>1)
    376 	SUB	r4, r4, #4*4		@ r4 = aX = in+(n>>1)-4
    377 	LDR	r11,[r5,#4]		@ r11= T[1]
    378 	LDR	r10,[r5],r2, LSL #2	@ r10= T[0]    T += step
    379 presymmetry_loop3:
    380 	LDR	r8,[r1],#16 		@ r8 = ro0 = bX[0]
    381 	LDR	r9,[r1,#8-16]		@ r9 = ro2 = bX[2]
    382 	LDR	r6,[r4]			@ r6 = ri0 = aX[0]
    383 
    384 	@ XNPROD31( ro2, ro0, T[1], T[0], 0xaX[0], &aX[2] )
    385 	@ aX[0] = (ro2*T[1] - ro0*T[0])>>31 aX[2] = (ro0*T[1] + ro2*T[0])>>31
    386 	SMULL	r14,r12,r8, r11		@ (r14,r12)  = ro0*T[1]
    387 	RSB	r8,r8,#0		@ r8 = -ro0
    388 	@ Stall ?
    389 	SMLAL	r14,r12,r9, r10		@ (r14,r12) += ro2*T[0]
    390 	LDR	r7,[r4,#8]		@ r7 = ri2 = aX[2]
    391 	@ Stall ?
    392 	SMULL	r14,r3, r9, r11		@ (r14,r3)   = ro2*T[1]
    393 	MOV	r12,r12,LSL #1
    394 	LDR	r11,[r5,#4]		@ r11= T[1]
    395 	SMLAL	r14,r3, r8, r10		@ (r14,r3)  -= ro0*T[0]
    396 	LDR	r10,[r5],r2, LSL #2	@ r10= T[0]    T += step
    397 	STR	r12,[r4,#8]
    398 	MOV	r3, r3, LSL #1
    399 	STR	r3, [r4],#-16
    400 
    401 	@ XNPROD31( ri2, ri0, T[0], T[1], 0xbX[0], &bX[2] )
    402 	@ bX[0] = (ri2*T[0] - ri0*T[1])>>31 bX[2] = (ri0*T[0] + ri2*T[1])>>31
    403 	SMULL	r14,r12,r6, r10		@ (r14,r12)  = ri0*T[0]
    404 	RSB	r6,r6,#0		@ r6 = -ri0
    405 	@ stall ?
    406 	SMLAL	r14,r12,r7, r11		@ (r14,r12) += ri2*T[1]
    407 	@ stall ?
    408 	@ stall ?
    409 	SMULL	r14,r3, r7, r10		@ (r14,r3)   = ri2*T[0]
    410 	MOV	r12,r12,LSL #1
    411 	@ stall ?
    412 	SMLAL	r14,r3, r6, r11		@ (r14,r3)  -= ri0*T[1]
    413 	CMP	r4,r1
    414 	STR	r12,[r1,#8-16]
    415 	MOV	r3, r3, LSL #1
    416 	STR	r3, [r1,#-16]
    417 
    418 	BGE	presymmetry_loop3
    419 
    420 	SUB	r1,r1,r0		@ r1 = in -= n>>2 (i.e. restore in)
    421 
    422 	LDR	r3,[r13]
    423 	STR	r2,[r13,#-4]!
    424 
    425 	@ mdct_butterflies
    426 	@ r0 = n  = (points * 2)
    427 	@ r1 = in = x
    428 	@ r2 = i
    429 	@ r3 = shift
    430 	STMFD	r13!,{r0-r1}
    431 	ADRL	r4, .Lsincos_lookup
    432 	LDR	r5, [r4]
    433 	ADD	r5, r4
    434 	RSBS	r4,r3,#6		@ r4 = stages = 7-shift then --stages
    435 	BLE	no_generics
    436 	MOV	r14,#4			@ r14= 4               (i=0)
    437 	MOV	r6, r14,LSL r3		@ r6 = (4<<i)<<shift
    438 mdct_butterflies_loop1:
    439 	MOV	r0, r0, LSR #1		@ r0 = points>>i = POINTS
    440 	MOV	r2, r14,LSR #2		@ r2 = (1<<i)-j        (j=0)
    441 	STMFD	r13!,{r4,r14}
    442 mdct_butterflies_loop2:
    443 
    444 	@ mdct_butterfly_generic(x+POINTS*j, POINTS, 4<<(i+shift))
    445 	@ mdct_butterfly_generic(r1, r0, r6)
    446 	@ r0 = points
    447 	@ r1 = x
    448 	@ preserve r2 (external loop counter)
    449 	@ preserve r3
    450 	@ preserve r4 (external loop counter)
    451 	@ r5 = T = sincos_lookup0
    452 	@ r6 = step
    453 	@ preserve r14
    454 
    455 	STR	r2,[r13,#-4]!		@ stack r2
    456 	ADD	r1,r1,r0,LSL #1		@ r1 = x2+4 = x + (POINTS>>1)
    457 	ADD	r7,r1,r0,LSL #1		@ r7 = x1+4 = x + POINTS
    458 	ADD	r12,r5,#1024*4		@ r12= sincos_lookup0+1024
    459 
    460 mdct_bufferfly_generic_loop1:
    461 	LDMDB	r7!,{r2,r3,r8,r11}	@ r2 = x1[0]
    462 					@ r3 = x1[1]
    463 					@ r8 = x1[2]
    464 					@ r11= x1[3]    x1 -= 4
    465 	LDMDB	r1!,{r4,r9,r10,r14}	@ r4 = x2[0]
    466 					@ r9 = x2[1]
    467 					@ r10= x2[2]
    468 					@ r14= x2[3]    x2 -= 4
    469 
    470 	SUB	r2, r2, r3		@ r2 = s0 = x1[0] - x1[1]
    471 	ADD	r3, r2, r3, LSL #1	@ r3 =      x1[0] + x1[1] (-> x1[0])
    472 	SUB	r11,r11,r8		@ r11= s1 = x1[3] - x1[2]
    473 	ADD	r8, r11,r8, LSL #1	@ r8 =      x1[3] + x1[2] (-> x1[2])
    474 	SUB	r9, r9, r4		@ r9 = s2 = x2[1] - x2[0]
    475 	ADD	r4, r9, r4, LSL #1	@ r4 =      x2[1] + x2[0] (-> x1[1])
    476 	SUB	r14,r14,r10		@ r14= s3 = x2[3] - x2[2]
    477 	ADD	r10,r14,r10,LSL #1	@ r10=      x2[3] + x2[2] (-> x1[3])
    478 	STMIA	r7,{r3,r4,r8,r10}
    479 
    480 	@ r0 = points
    481 	@ r1 = x2
    482 	@ r2 = s0
    483 	@ r3 free
    484 	@ r4 free
    485 	@ r5 = T
    486 	@ r6 = step
    487 	@ r7 = x1
    488 	@ r8 free
    489 	@ r9 = s2
    490 	@ r10 free
    491 	@ r11= s1
    492 	@ r12= limit
    493 	@ r14= s3
    494 
    495 	LDR	r8, [r5,#4]		@ r8 = T[1]
    496 	LDR	r10,[r5],r6,LSL #2	@ r10= T[0]		T += step
    497 
    498 	@ XPROD31(s1, s0, T[0], T[1], &x2[0], &x2[2])
    499 	@ x2[0] = (s1*T[0] + s0*T[1])>>31     x2[2] = (s0*T[0] - s1*T[1])>>31
    500 	@ stall Xscale
    501 	SMULL	r4, r3, r2, r8		@ (r4, r3)   = s0*T[1]
    502 	SMLAL	r4, r3, r11,r10		@ (r4, r3)  += s1*T[0]
    503 	RSB	r11,r11,#0
    504 	SMULL	r11,r4, r8, r11		@ (r11,r4)   = -s1*T[1]
    505 	SMLAL	r11,r4, r2, r10		@ (r11,r4)  += s0*T[0]
    506 	MOV	r2, r3, LSL #1		@ r2 = r3<<1 = Value for x2[0]
    507 
    508 	@ XPROD31(s2, s3, T[0], T[1], &x2[1], &x2[3])
    509 	@ x2[1] = (s2*T[0] + s3*T[1])>>31     x2[3] = (s3*T[0] - s2*T[1])>>31
    510 	SMULL	r11,r3, r9, r10		@ (r11,r3)   = s2*T[0]
    511 	MOV	r4, r4, LSL #1		@ r4 = r4<<1 = Value for x2[2]
    512 	SMLAL	r11,r3, r14,r8		@ (r11,r3)  += s3*T[1]
    513 	RSB	r9, r9, #0
    514 	SMULL	r10,r11,r14,r10		@ (r10,r11)  = s3*T[0]
    515 	MOV	r3, r3, LSL #1		@ r3 = r3<<1 = Value for x2[1]
    516 	SMLAL	r10,r11,r9,r8		@ (r10,r11) -= s2*T[1]
    517 	CMP	r5, r12
    518 	MOV	r11,r11,LSL #1		@ r11= r11<<1 = Value for x2[3]
    519 
    520 	STMIA	r1,{r2,r3,r4,r11}
    521 
    522 	BLT	mdct_bufferfly_generic_loop1
    523 
    524 	SUB	r12,r12,#1024*4
    525 mdct_bufferfly_generic_loop2:
    526 	LDMDB	r7!,{r2,r3,r9,r10}	@ r2 = x1[0]
    527 					@ r3 = x1[1]
    528 					@ r9 = x1[2]
    529 					@ r10= x1[3]    x1 -= 4
    530 	LDMDB	r1!,{r4,r8,r11,r14}	@ r4 = x2[0]
    531 					@ r8 = x2[1]
    532 					@ r11= x2[2]
    533 					@ r14= x2[3]    x2 -= 4
    534 
    535 	SUB	r2, r2, r3		@ r2 = s0 = x1[0] - x1[1]
    536 	ADD	r3, r2, r3, LSL #1	@ r3 =      x1[0] + x1[1] (-> x1[0])
    537 	SUB	r9, r9,r10		@ r9 = s1 = x1[2] - x1[3]
    538 	ADD	r10,r9,r10, LSL #1	@ r10=      x1[2] + x1[3] (-> x1[2])
    539 	SUB	r4, r4, r8		@ r4 = s2 = x2[0] - x2[1]
    540 	ADD	r8, r4, r8, LSL #1	@ r8 =      x2[0] + x2[1] (-> x1[1])
    541 	SUB	r14,r14,r11		@ r14= s3 = x2[3] - x2[2]
    542 	ADD	r11,r14,r11,LSL #1	@ r11=      x2[3] + x2[2] (-> x1[3])
    543 	STMIA	r7,{r3,r8,r10,r11}
    544 
    545 	@ r0 = points
    546 	@ r1 = x2
    547 	@ r2 = s0
    548 	@ r3 free
    549 	@ r4 = s2
    550 	@ r5 = T
    551 	@ r6 = step
    552 	@ r7 = x1
    553 	@ r8 free
    554 	@ r9 = s1
    555 	@ r10 free
    556 	@ r11 free
    557 	@ r12= limit
    558 	@ r14= s3
    559 
    560 	LDR	r8, [r5,#4]		@ r8 = T[1]
    561 	LDR	r10,[r5],-r6,LSL #2	@ r10= T[0]		T -= step
    562 
    563 	@ XNPROD31(s0, s1, T[0], T[1], &x2[0], &x2[2])
    564 	@ x2[0] = (s0*T[0] - s1*T[1])>>31     x2[2] = (s1*T[0] + s0*T[1])>>31
    565 	@ stall Xscale
    566 	SMULL	r3, r11,r2, r8		@ (r3, r11)  = s0*T[1]
    567 	SMLAL	r3, r11,r9, r10		@ (r3, r11) += s1*T[0]
    568 	RSB	r9, r9, #0
    569 	SMULL	r3, r2, r10,r2		@ (r3, r2)   = s0*T[0]
    570 	SMLAL	r3, r2, r9, r8		@ (r3, r2)  += -s1*T[1]
    571 	MOV	r9, r11,LSL #1		@ r9 = r11<<1 = Value for x2[2]
    572 
    573 	@ XNPROD31(s3, s2, T[0], T[1], &x2[1], &x2[3])
    574 	@ x2[1] = (s3*T[0] - s2*T[1])>>31     x2[3] = (s2*T[0] + s3*T[1])>>31
    575 	SMULL	r3, r11,r4, r10		@ (r3,r11)   = s2*T[0]
    576 	MOV	r2, r2, LSL #1		@ r2 = r2<<1  = Value for x2[0]
    577 	SMLAL	r3, r11,r14,r8		@ (r3,r11)  += s3*T[1]
    578 	RSB	r4, r4, #0
    579 	SMULL	r10,r3,r14,r10		@ (r10,r3)   = s3*T[0]
    580 	MOV	r11,r11,LSL #1		@ r11= r11<<1 = Value for x2[3]
    581 	SMLAL	r10,r3, r4, r8		@ (r10,r3)  -= s2*T[1]
    582 	CMP	r5, r12
    583 	MOV	r3, r3, LSL #1		@ r3 = r3<<1  = Value for x2[1]
    584 
    585 	STMIA	r1,{r2,r3,r9,r11}
    586 
    587 	BGT	mdct_bufferfly_generic_loop2
    588 
    589 	LDR	r2,[r13],#4		@ unstack r2
    590 	ADD	r1, r1, r0, LSL #2	@ r1 = x+POINTS*j
    591 	@ stall Xscale
    592 	SUBS	r2, r2, #1		@ r2--                 (j++)
    593 	BGT	mdct_butterflies_loop2
    594 
    595 	LDMFD	r13!,{r4,r14}
    596 
    597 	LDR	r1,[r13,#4]
    598 
    599 	SUBS	r4, r4, #1		@ stages--
    600 	MOV	r14,r14,LSL #1		@ r14= 4<<i            (i++)
    601 	MOV	r6, r6, LSL #1		@ r6 = step <<= 1      (i++)
    602 	BGE	mdct_butterflies_loop1
    603 	LDMFD	r13,{r0-r1}
    604 no_generics:
    605 	@ mdct_butterflies part2 (loop around mdct_bufferfly_32)
    606 	@ r0 = points
    607 	@ r1 = in
    608 	@ r2 = step
    609 	@ r3 = shift
    610 
    611 mdct_bufferflies_loop3:
    612 	@ mdct_bufferfly_32
    613 
    614 	@ block1
    615 	ADD	r4, r1, #16*4		@ r4 = &in[16]
    616 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[16]
    617 					@ r6 = x[17]
    618 					@ r9 = x[18]
    619 					@ r10= x[19]
    620 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[0]
    621 					@ r8 = x[1]
    622 					@ r11= x[2]
    623 					@ r12= x[3]
    624 	SUB	r5, r5, r6		@ r5 = s0 = x[16] - x[17]
    625 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[16] + x[17]  -> x[16]
    626 	SUB	r9, r9, r10		@ r9 = s1 = x[18] - x[19]
    627 	ADD	r10,r9, r10,LSL #1	@ r10=      x[18] + x[19]  -> x[18]
    628 	SUB	r8, r8, r7		@ r8 = s2 = x[ 1] - x[ 0]
    629 	ADD	r7, r8, r7, LSL #1	@ r7 =      x[ 1] + x[ 0]  -> x[17]
    630 	SUB	r12,r12,r11		@ r12= s3 = x[ 3] - x[ 2]
    631 	ADD	r11,r12,r11, LSL #1	@ r11=      x[ 3] + x[ 2]  -> x[19]
    632 	STMIA	r4!,{r6,r7,r10,r11}
    633 
    634 	LDR	r6,cPI1_8
    635 	LDR	r7,cPI3_8
    636 
    637 	@ XNPROD31( s0, s1, cPI3_8, cPI1_8, &x[ 0], &x[ 2] )
    638 	@ x[0] = s0*cPI3_8 - s1*cPI1_8     x[2] = s1*cPI3_8 + s0*cPI1_8
    639 	@ stall Xscale
    640 	SMULL	r14,r11,r5, r6		@ (r14,r11)  = s0*cPI1_8
    641 	SMLAL	r14,r11,r9, r7		@ (r14,r11) += s1*cPI3_8
    642 	RSB	r9, r9, #0
    643 	SMULL	r14,r5, r7, r5		@ (r14,r5)   = s0*cPI3_8
    644 	SMLAL	r14,r5, r9, r6		@ (r14,r5)  -= s1*cPI1_8
    645 	MOV	r11,r11,LSL #1
    646 	MOV	r5, r5, LSL #1
    647 
    648 	@ XPROD31 ( s2, s3, cPI1_8, cPI3_8, &x[ 1], &x[ 3] )
    649 	@ x[1] = s2*cPI1_8 + s3*cPI3_8     x[3] = s3*cPI1_8 - s2*cPI3_8
    650 	SMULL	r14,r9, r8, r6		@ (r14,r9)   = s2*cPI1_8
    651 	SMLAL	r14,r9, r12,r7		@ (r14,r9)  += s3*cPI3_8
    652 	RSB	r8,r8,#0
    653 	SMULL	r14,r12,r6, r12		@ (r14,r12)  = s3*cPI1_8
    654 	SMLAL	r14,r12,r8, r7		@ (r14,r12) -= s2*cPI3_8
    655 	MOV	r9, r9, LSL #1
    656 	MOV	r12,r12,LSL #1
    657 	STMIA	r1!,{r5,r9,r11,r12}
    658 
    659 	@ block2
    660 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[20]
    661 					@ r6 = x[21]
    662 					@ r9 = x[22]
    663 					@ r10= x[23]
    664 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[4]
    665 					@ r8 = x[5]
    666 					@ r11= x[6]
    667 					@ r12= x[7]
    668 	SUB	r5, r5, r6		@ r5 = s0 = x[20] - x[21]
    669 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[20] + x[21]  -> x[20]
    670 	SUB	r9, r9, r10		@ r9 = s1 = x[22] - x[23]
    671 	ADD	r10,r9, r10,LSL #1	@ r10=      x[22] + x[23]  -> x[22]
    672 	SUB	r8, r8, r7		@ r8 = s2 = x[ 5] - x[ 4]
    673 	ADD	r7, r8, r7, LSL #1	@ r7 =      x[ 5] + x[ 4]  -> x[21]
    674 	SUB	r12,r12,r11		@ r12= s3 = x[ 7] - x[ 6]
    675 	ADD	r11,r12,r11, LSL #1	@ r11=      x[ 7] + x[ 6]  -> x[23]
    676 	LDR	r14,cPI2_8
    677 	STMIA	r4!,{r6,r7,r10,r11}
    678 
    679 	SUB	r5, r5, r9		@ r5 = s0 - s1
    680 	ADD	r9, r5, r9, LSL #1	@ r9 = s0 + s1
    681 	SMULL	r6, r5, r14,r5		@ (r6,r5)  = (s0-s1)*cPI2_8
    682 	SUB	r12,r12,r8		@ r12= s3 - s2
    683 	ADD	r8, r12,r8, LSL #1	@ r8 = s3 + s2
    684 
    685 	SMULL	r6, r8, r14,r8		@ (r6,r8)  = (s3+s2)*cPI2_8
    686 	MOV	r5, r5, LSL #1
    687 	SMULL	r6, r9, r14,r9		@ (r6,r9)  = (s0+s1)*cPI2_8
    688 	MOV	r8, r8, LSL #1
    689 	SMULL	r6, r12,r14,r12		@ (r6,r12) = (s3-s2)*cPI2_8
    690 	MOV	r9, r9, LSL #1
    691 	MOV	r12,r12,LSL #1
    692 	STMIA	r1!,{r5,r8,r9,r12}
    693 
    694 	@ block3
    695 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[24]
    696 					@ r6 = x[25]
    697 					@ r9 = x[25]
    698 					@ r10= x[26]
    699 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[8]
    700 					@ r8 = x[9]
    701 					@ r11= x[10]
    702 					@ r12= x[11]
    703 	SUB	r5, r5, r6		@ r5 = s0 = x[24] - x[25]
    704 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[24] + x[25]  -> x[25]
    705 	SUB	r9, r9, r10		@ r9 = s1 = x[26] - x[27]
    706 	ADD	r10,r9, r10,LSL #1	@ r10=      x[26] + x[27]  -> x[26]
    707 	SUB	r8, r8, r7		@ r8 = s2 = x[ 9] - x[ 8]
    708 	ADD	r7, r8, r7, LSL #1	@ r7 =      x[ 9] + x[ 8]  -> x[25]
    709 	SUB	r12,r12,r11		@ r12= s3 = x[11] - x[10]
    710 	ADD	r11,r12,r11, LSL #1	@ r11=      x[11] + x[10]  -> x[27]
    711 	STMIA	r4!,{r6,r7,r10,r11}
    712 
    713 	LDR	r6,cPI3_8
    714 	LDR	r7,cPI1_8
    715 
    716 	@ XNPROD31( s0, s1, cPI1_8, cPI3_8, &x[ 8], &x[10] )
    717 	@ x[8] = s0*cPI1_8 - s1*cPI3_8     x[10] = s1*cPI1_8 + s0*cPI3_8
    718 	@ stall Xscale
    719 	SMULL	r14,r11,r5, r6		@ (r14,r11)  = s0*cPI3_8
    720 	SMLAL	r14,r11,r9, r7		@ (r14,r11) += s1*cPI1_8
    721 	RSB	r9, r9, #0
    722 	SMULL	r14,r5, r7, r5		@ (r14,r5)   = s0*cPI1_8
    723 	SMLAL	r14,r5, r9, r6		@ (r14,r5)  -= s1*cPI3_8
    724 	MOV	r11,r11,LSL #1
    725 	MOV	r5, r5, LSL #1
    726 
    727 	@ XPROD31 ( s2, s3, cPI3_8, cPI1_8, &x[ 9], &x[11] )
    728 	@ x[9] = s2*cPI3_8 + s3*cPI1_8     x[11] = s3*cPI3_8 - s2*cPI1_8
    729 	SMULL	r14,r9, r8, r6		@ (r14,r9)   = s2*cPI3_8
    730 	SMLAL	r14,r9, r12,r7		@ (r14,r9)  += s3*cPI1_8
    731 	RSB	r8,r8,#0
    732 	SMULL	r14,r12,r6, r12		@ (r14,r12)  = s3*cPI3_8
    733 	SMLAL	r14,r12,r8, r7		@ (r14,r12) -= s2*cPI1_8
    734 	MOV	r9, r9, LSL #1
    735 	MOV	r12,r12,LSL #1
    736 	STMIA	r1!,{r5,r9,r11,r12}
    737 
    738 	@ block4
    739 	LDMIA	r4,{r5,r6,r10,r11}	@ r5 = x[28]
    740 					@ r6 = x[29]
    741 					@ r10= x[30]
    742 					@ r11= x[31]
    743 	LDMIA	r1,{r8,r9,r12,r14}	@ r8 = x[12]
    744 					@ r9 = x[13]
    745 					@ r12= x[14]
    746 					@ r14= x[15]
    747 	SUB	r5, r5, r6		@ r5 = s0 = x[28] - x[29]
    748 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[28] + x[29]  -> x[28]
    749 	SUB	r7, r14,r12		@ r7 = s3 = x[15] - x[14]
    750 	ADD	r12,r7, r12, LSL #1	@ r12=      x[15] + x[14]  -> x[31]
    751 	SUB	r10,r10,r11		@ r10= s1 = x[30] - x[31]
    752 	ADD	r11,r10,r11,LSL #1	@ r11=      x[30] + x[31]  -> x[30]
    753 	SUB	r14, r8, r9		@ r14= s2 = x[12] - x[13]
    754 	ADD	r9, r14, r9, LSL #1	@ r9 =      x[12] + x[13]  -> x[29]
    755 	STMIA	r4!,{r6,r9,r11,r12}
    756 	STMIA	r1!,{r5,r7,r10,r14}
    757 
    758 	@ mdct_butterfly16 (1st version)
    759 	@ block 1
    760 	SUB	r1,r1,#16*4
    761 	ADD	r4,r1,#8*4
    762 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[ 8]
    763 					@ r6 = x[ 9]
    764 					@ r9 = x[10]
    765 					@ r10= x[11]
    766 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[0]
    767 					@ r8 = x[1]
    768 					@ r11= x[2]
    769 					@ r12= x[3]
    770 	SUB	r5, r5, r6		@ r5 = s0 = x[ 8] - x[ 9]
    771 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[ 8] + x[ 9]  -> x[ 8]
    772 	SUB	r9, r9, r10		@ r9 = s1 = x[10] - x[11]
    773 	ADD	r10,r9, r10,LSL #1	@ r10=      x[10] + x[11]  -> x[10]
    774 	SUB	r8, r8, r7		@ r8 = s2 = x[ 1] - x[ 0]
    775 	ADD	r7, r8, r7, LSL #1	@ r7 =      x[ 1] + x[ 0]  -> x[ 9]
    776 	SUB	r12,r12,r11		@ r12= s3 = x[ 3] - x[ 2]
    777 	ADD	r11,r12,r11, LSL #1	@ r11=      x[ 3] + x[ 2]  -> x[11]
    778 	LDR	r14,cPI2_8
    779 	STMIA	r4!,{r6,r7,r10,r11}
    780 
    781 	SUB	r5, r5, r9		@ r5 = s0 - s1
    782 	ADD	r9, r5, r9, LSL #1	@ r9 = s0 + s1
    783 	SMULL	r6, r5, r14,r5		@ (r6,r5)  = (s0-s1)*cPI2_8
    784 	SUB	r12,r12,r8		@ r12= s3 - s2
    785 	ADD	r8, r12,r8, LSL #1	@ r8 = s3 + s2
    786 
    787 	SMULL	r6, r8, r14,r8		@ (r6,r8)  = (s3+s2)*cPI2_8
    788 	MOV	r5, r5, LSL #1
    789 	SMULL	r6, r9, r14,r9		@ (r6,r9)  = (s0+s1)*cPI2_8
    790 	MOV	r8, r8, LSL #1
    791 	SMULL	r6, r12,r14,r12		@ (r6,r12) = (s3-s2)*cPI2_8
    792 	MOV	r9, r9, LSL #1
    793 	MOV	r12,r12,LSL #1
    794 	STMIA	r1!,{r5,r8,r9,r12}
    795 
    796 	@ block4
    797 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[12]
    798 					@ r6 = x[13]
    799 					@ r9 = x[14]
    800 					@ r10= x[15]
    801 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[ 4]
    802 					@ r8 = x[ 5]
    803 					@ r11= x[ 6]
    804 					@ r12= x[ 7]
    805 	SUB	r14,r7, r8		@ r14= s0 = x[ 4] - x[ 5]
    806 	ADD	r8, r14,r8, LSL #1	@ r8 =      x[ 4] + x[ 5]  -> x[13]
    807 	SUB	r7, r12,r11		@ r7 = s1 = x[ 7] - x[ 6]
    808 	ADD	r11,r7, r11, LSL #1	@ r11=      x[ 7] + x[ 6]  -> x[15]
    809 	SUB	r5, r5, r6		@ r5 = s2 = x[12] - x[13]
    810 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[12] + x[13]  -> x[12]
    811 	SUB	r12,r9, r10		@ r12= s3 = x[14] - x[15]
    812 	ADD	r10,r12,r10,LSL #1	@ r10=      x[14] + x[15]  -> x[14]
    813 	STMIA	r4!,{r6,r8,r10,r11}
    814 	STMIA	r1!,{r5,r7,r12,r14}
    815 
    816 	@ mdct_butterfly_8
    817 	LDMDB	r1,{r6,r7,r8,r9,r10,r11,r12,r14}
    818 					@ r6 = x[0]
    819 					@ r7 = x[1]
    820 					@ r8 = x[2]
    821 					@ r9 = x[3]
    822 					@ r10= x[4]
    823 					@ r11= x[5]
    824 					@ r12= x[6]
    825 					@ r14= x[7]
    826 	ADD	r6, r6, r7		@ r6 = s0 = x[0] + x[1]
    827 	SUB	r7, r6, r7, LSL #1	@ r7 = s1 = x[0] - x[1]
    828 	ADD	r8, r8, r9		@ r8 = s2 = x[2] + x[3]
    829 	SUB	r9, r8, r9, LSL #1	@ r9 = s3 = x[2] - x[3]
    830 	ADD	r10,r10,r11		@ r10= s4 = x[4] + x[5]
    831 	SUB	r11,r10,r11,LSL #1	@ r11= s5 = x[4] - x[5]
    832 	ADD	r12,r12,r14		@ r12= s6 = x[6] + x[7]
    833 	SUB	r14,r12,r14,LSL #1	@ r14= s7 = x[6] - x[7]
    834 
    835 	ADD	r2, r11,r9		@ r2 = x[0] = s5 + s3
    836 	SUB	r4, r2, r9, LSL #1	@ r4 = x[2] = s5 - s3
    837 	SUB	r3, r14,r7		@ r3 = x[1] = s7 - s1
    838 	ADD	r5, r3, r7, LSL #1	@ r5 = x[3] = s7 + s1
    839 	SUB	r10,r10,r6		@ r10= x[4] = s4 - s0
    840 	SUB	r11,r12,r8		@ r11= x[5] = s6 - s2
    841 	ADD	r12,r10,r6, LSL #1	@ r12= x[6] = s4 + s0
    842 	ADD	r14,r11,r8, LSL #1	@ r14= x[7] = s6 + s2
    843 	STMDB	r1,{r2,r3,r4,r5,r10,r11,r12,r14}
    844 
    845 	@ mdct_butterfly_8
    846 	LDMIA	r1,{r6,r7,r8,r9,r10,r11,r12,r14}
    847 					@ r6 = x[0]
    848 					@ r7 = x[1]
    849 					@ r8 = x[2]
    850 					@ r9 = x[3]
    851 					@ r10= x[4]
    852 					@ r11= x[5]
    853 					@ r12= x[6]
    854 					@ r14= x[7]
    855 	ADD	r6, r6, r7		@ r6 = s0 = x[0] + x[1]
    856 	SUB	r7, r6, r7, LSL #1	@ r7 = s1 = x[0] - x[1]
    857 	ADD	r8, r8, r9		@ r8 = s2 = x[2] + x[3]
    858 	SUB	r9, r8, r9, LSL #1	@ r9 = s3 = x[2] - x[3]
    859 	ADD	r10,r10,r11		@ r10= s4 = x[4] + x[5]
    860 	SUB	r11,r10,r11,LSL #1	@ r11= s5 = x[4] - x[5]
    861 	ADD	r12,r12,r14		@ r12= s6 = x[6] + x[7]
    862 	SUB	r14,r12,r14,LSL #1	@ r14= s7 = x[6] - x[7]
    863 
    864 	ADD	r2, r11,r9		@ r2 = x[0] = s5 + s3
    865 	SUB	r4, r2, r9, LSL #1	@ r4 = x[2] = s5 - s3
    866 	SUB	r3, r14,r7		@ r3 = x[1] = s7 - s1
    867 	ADD	r5, r3, r7, LSL #1	@ r5 = x[3] = s7 + s1
    868 	SUB	r10,r10,r6		@ r10= x[4] = s4 - s0
    869 	SUB	r11,r12,r8		@ r11= x[5] = s6 - s2
    870 	ADD	r12,r10,r6, LSL #1	@ r12= x[6] = s4 + s0
    871 	ADD	r14,r11,r8, LSL #1	@ r14= x[7] = s6 + s2
    872 	STMIA	r1,{r2,r3,r4,r5,r10,r11,r12,r14}
    873 
    874 	@ block 2
    875 	ADD	r1,r1,#16*4-8*4
    876 	ADD	r4,r1,#8*4
    877 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[ 8]
    878 					@ r6 = x[ 9]
    879 					@ r9 = x[10]
    880 					@ r10= x[11]
    881 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[0]
    882 					@ r8 = x[1]
    883 					@ r11= x[2]
    884 					@ r12= x[3]
    885 	SUB	r5, r5, r6		@ r5 = s0 = x[ 8] - x[ 9]
    886 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[ 8] + x[ 9]  -> x[ 8]
    887 	SUB	r9, r9, r10		@ r9 = s1 = x[10] - x[11]
    888 	ADD	r10,r9, r10,LSL #1	@ r10=      x[10] + x[11]  -> x[10]
    889 	SUB	r8, r8, r7		@ r8 = s2 = x[ 1] - x[ 0]
    890 	ADD	r7, r8, r7, LSL #1	@ r7 =      x[ 1] + x[ 0]  -> x[ 9]
    891 	SUB	r12,r12,r11		@ r12= s3 = x[ 3] - x[ 2]
    892 	ADD	r11,r12,r11, LSL #1	@ r11=      x[ 3] + x[ 2]  -> x[11]
    893 	LDR	r14,cPI2_8
    894 	STMIA	r4!,{r6,r7,r10,r11}
    895 
    896 	SUB	r5, r5, r9		@ r5 = s0 - s1
    897 	ADD	r9, r5, r9, LSL #1	@ r9 = s0 + s1
    898 	SMULL	r6, r5, r14,r5		@ (r6,r5)  = (s0-s1)*cPI2_8
    899 	SUB	r12,r12,r8		@ r12= s3 - s2
    900 	ADD	r8, r12,r8, LSL #1	@ r8 = s3 + s2
    901 
    902 	SMULL	r6, r8, r14,r8		@ (r6,r8)  = (s3+s2)*cPI2_8
    903 	MOV	r5, r5, LSL #1
    904 	SMULL	r6, r9, r14,r9		@ (r6,r9)  = (s0+s1)*cPI2_8
    905 	MOV	r8, r8, LSL #1
    906 	SMULL	r6, r12,r14,r12		@ (r6,r12) = (s3-s2)*cPI2_8
    907 	MOV	r9, r9, LSL #1
    908 	MOV	r12,r12,LSL #1
    909 	STMIA	r1!,{r5,r8,r9,r12}
    910 
    911 	@ block4
    912 	LDMIA	r4,{r5,r6,r9,r10}	@ r5 = x[12]
    913 					@ r6 = x[13]
    914 					@ r9 = x[14]
    915 					@ r10= x[15]
    916 	LDMIA	r1,{r7,r8,r11,r12}	@ r7 = x[ 4]
    917 					@ r8 = x[ 5]
    918 					@ r11= x[ 6]
    919 					@ r12= x[ 7]
    920 	SUB	r5, r5, r6		@ r5 = s2 = x[12] - x[13]
    921 	ADD	r6, r5, r6, LSL #1	@ r6 =      x[12] + x[13]  -> x[12]
    922 	SUB	r9, r9, r10		@ r9 = s3 = x[14] - x[15]
    923 	ADD	r10,r9, r10,LSL #1	@ r10=      x[14] + x[15]  -> x[14]
    924 	SUB	r14,r7, r8		@ r14= s0 = x[ 4] - x[ 5]
    925 	ADD	r8, r14,r8, LSL #1	@ r8 =      x[ 4] + x[ 5]  -> x[13]
    926 	SUB	r7, r12,r11		@ r7 = s1 = x[ 7] - x[ 6]
    927 	ADD	r11,r7, r11, LSL #1	@ r11=      x[ 7] + x[ 6]  -> x[15]
    928 	STMIA	r4!,{r6,r8,r10,r11}
    929 	STMIA	r1!,{r5,r7,r9,r14}
    930 
    931 	@ mdct_butterfly_8
    932 	LDMDB	r1,{r6,r7,r8,r9,r10,r11,r12,r14}
    933 					@ r6 = x[0]
    934 					@ r7 = x[1]
    935 					@ r8 = x[2]
    936 					@ r9 = x[3]
    937 					@ r10= x[4]
    938 					@ r11= x[5]
    939 					@ r12= x[6]
    940 					@ r14= x[7]
    941 	ADD	r6, r6, r7		@ r6 = s0 = x[0] + x[1]
    942 	SUB	r7, r6, r7, LSL #1	@ r7 = s1 = x[0] - x[1]
    943 	ADD	r8, r8, r9		@ r8 = s2 = x[2] + x[3]
    944 	SUB	r9, r8, r9, LSL #1	@ r9 = s3 = x[2] - x[3]
    945 	ADD	r10,r10,r11		@ r10= s4 = x[4] + x[5]
    946 	SUB	r11,r10,r11,LSL #1	@ r11= s5 = x[4] - x[5]
    947 	ADD	r12,r12,r14		@ r12= s6 = x[6] + x[7]
    948 	SUB	r14,r12,r14,LSL #1	@ r14= s7 = x[6] - x[7]
    949 
    950 	ADD	r2, r11,r9		@ r2 = x[0] = s5 + s3
    951 	SUB	r4, r2, r9, LSL #1	@ r4 = x[2] = s5 - s3
    952 	SUB	r3, r14,r7		@ r3 = x[1] = s7 - s1
    953 	ADD	r5, r3, r7, LSL #1	@ r5 = x[3] = s7 + s1
    954 	SUB	r10,r10,r6		@ r10= x[4] = s4 - s0
    955 	SUB	r11,r12,r8		@ r11= x[5] = s6 - s2
    956 	ADD	r12,r10,r6, LSL #1	@ r12= x[6] = s4 + s0
    957 	ADD	r14,r11,r8, LSL #1	@ r14= x[7] = s6 + s2
    958 	STMDB	r1,{r2,r3,r4,r5,r10,r11,r12,r14}
    959 
    960 	@ mdct_butterfly_8
    961 	LDMIA	r1,{r6,r7,r8,r9,r10,r11,r12,r14}
    962 					@ r6 = x[0]
    963 					@ r7 = x[1]
    964 					@ r8 = x[2]
    965 					@ r9 = x[3]
    966 					@ r10= x[4]
    967 					@ r11= x[5]
    968 					@ r12= x[6]
    969 					@ r14= x[7]
    970 	ADD	r6, r6, r7		@ r6 = s0 = x[0] + x[1]
    971 	SUB	r7, r6, r7, LSL #1	@ r7 = s1 = x[0] - x[1]
    972 	ADD	r8, r8, r9		@ r8 = s2 = x[2] + x[3]
    973 	SUB	r9, r8, r9, LSL #1	@ r9 = s3 = x[2] - x[3]
    974 	ADD	r10,r10,r11		@ r10= s4 = x[4] + x[5]
    975 	SUB	r11,r10,r11,LSL #1	@ r11= s5 = x[4] - x[5]
    976 	ADD	r12,r12,r14		@ r12= s6 = x[6] + x[7]
    977 	SUB	r14,r12,r14,LSL #1	@ r14= s7 = x[6] - x[7]
    978 
    979 	ADD	r2, r11,r9		@ r2 = x[0] = s5 + s3
    980 	SUB	r4, r2, r9, LSL #1	@ r4 = x[2] = s5 - s3
    981 	SUB	r3, r14,r7		@ r3 = x[1] = s7 - s1
    982 	ADD	r5, r3, r7, LSL #1	@ r5 = x[3] = s7 + s1
    983 	SUB	r10,r10,r6		@ r10= x[4] = s4 - s0
    984 	SUB	r11,r12,r8		@ r11= x[5] = s6 - s2
    985 	ADD	r12,r10,r6, LSL #1	@ r12= x[6] = s4 + s0
    986 	ADD	r14,r11,r8, LSL #1	@ r14= x[7] = s6 + s2
    987 	STMIA	r1,{r2,r3,r4,r5,r10,r11,r12,r14}
    988 
    989 	ADD	r1,r1,#8*4
    990 	SUBS	r0,r0,#64
    991 	BGT	mdct_bufferflies_loop3
    992 
    993 	LDMFD	r13,{r0-r3}
    994 
    995 mdct_bitreverseARM:
    996 	@ r0 = points = n
    997 	@ r1 = in
    998 	@ r2 = step
    999 	@ r3 = shift
   1000 
   1001 	MOV	r4, #0			@ r4 = bit = 0
   1002 	ADD	r5, r1, r0, LSL #1	@ r5 = w = x + (n>>1)
   1003 	ADR	r6, bitrev
   1004 	SUB	r5, r5, #8
   1005 brev_lp:
   1006 	LDRB	r7, [r6, r4, LSR #6]
   1007 	AND	r8, r4, #0x3f
   1008 	LDRB	r8, [r6, r8]
   1009 	ADD	r4, r4, #1		@ bit++
   1010 	@ stall XScale
   1011 	ORR	r7, r7, r8, LSL #6	@ r7 = bitrev[bit]
   1012 	MOV	r7, r7, LSR r3
   1013 	ADD	r9, r1, r7, LSL #2	@ r9 = xx = x + (b>>shift)
   1014 	CMP	r5, r9			@ if (w > xx)
   1015 	LDR	r10,[r5],#-8		@   r10 = w[0]		w -= 2
   1016 	LDRGT	r11,[r5,#12]		@   r11 = w[1]
   1017 	LDRGT	r12,[r9]		@   r12 = xx[0]
   1018 	LDRGT	r14,[r9,#4]		@   r14 = xx[1]
   1019 	STRGT	r10,[r9]		@   xx[0]= w[0]
   1020 	STRGT	r11,[r9,#4]		@   xx[1]= w[1]
   1021 	STRGT	r12,[r5,#8]		@   w[0] = xx[0]
   1022 	STRGT	r14,[r5,#12]		@   w[1] = xx[1]
   1023 	CMP	r5,r1
   1024 	BGT	brev_lp
   1025 
   1026 	@ mdct_step7
   1027 	@ r0 = points
   1028 	@ r1 = in
   1029 	@ r2 = step
   1030 	@ r3 = shift
   1031 
   1032 	CMP	r2, #4			@ r5 = T = (step>=4) ?
   1033 	ADR	r7, .Lsincos_lookup	@          sincos_lookup0 +
   1034 	ADDLT	r7, #4			@          sincos_lookup1
   1035 	LDR	r5, [r7]
   1036 	ADD	r5, r7
   1037 	ADD	r7, r1, r0, LSL #1	@ r7 = w1 = x + (n>>1)
   1038 	ADDGE	r5, r5, r2, LSL #1	@		            (step>>1)
   1039 	ADD	r8, r5, #1024*4		@ r8 = Ttop
   1040 step7_loop1:
   1041 	LDR	r6, [r1]		@ r6 = w0[0]
   1042 	LDR	r9, [r1,#4]		@ r9 = w0[1]
   1043 	LDR	r10,[r7,#-8]!		@ r10= w1[0]	w1 -= 2
   1044 	LDR	r11,[r7,#4]		@ r11= w1[1]
   1045 	LDR	r14,[r5,#4]		@ r14= T[1]
   1046 	LDR	r12,[r5],r2,LSL #2	@ r12= T[0]	T += step
   1047 
   1048 	ADD	r6, r6, r10		@ r6 = s0 = w0[0] + w1[0]
   1049 	SUB	r10,r6, r10,LSL #1	@ r10= s1b= w0[0] - w1[0]
   1050 	SUB	r11,r11,r9		@ r11= s1 = w1[1] - w0[1]
   1051 	ADD	r9, r11,r9, LSL #1	@ r9 = s0b= w1[1] + w0[1]
   1052 
   1053 	@ Can save 1 cycle by using SMULL SMLAL - at the cost of being
   1054 	@ 1 off.
   1055 	SMULL	r0, r3, r6, r14		@ (r0,r3)   = s0*T[1]
   1056 	SMULL	r0, r4, r11,r12		@ (r0,r4)  += s1*T[0] = s2
   1057 	ADD	r3, r3, r4
   1058 	SMULL	r0, r14,r11,r14		@ (r0,r14)  = s1*T[1]
   1059 	SMULL	r0, r12,r6, r12		@ (r0,r12) += s0*T[0] = s3
   1060 	SUB	r14,r14,r12
   1061 
   1062 	@ r9 = s0b<<1
   1063 	@ r10= s1b<<1
   1064 	ADD	r9, r3, r9, ASR #1	@ r9 = s0b + s2
   1065 	SUB	r3, r9, r3, LSL #1	@ r3 = s0b - s2
   1066 
   1067 	SUB	r12,r14,r10,ASR #1	@ r12= s3  - s1b
   1068 	ADD	r10,r14,r10,ASR #1	@ r10= s3  + s1b
   1069 	STR	r9, [r1],#4
   1070 	STR	r10,[r1],#4		@ w0 += 2
   1071 	STR	r3, [r7]
   1072 	STR	r12,[r7,#4]
   1073 
   1074 	CMP	r5,r8
   1075 	BLT	step7_loop1
   1076 
   1077 step7_loop2:
   1078 	LDR	r6, [r1]		@ r6 = w0[0]
   1079 	LDR	r9, [r1,#4]		@ r9 = w0[1]
   1080 	LDR	r10,[r7,#-8]!		@ r10= w1[0]	w1 -= 2
   1081 	LDR	r11,[r7,#4]		@ r11= w1[1]
   1082 	LDR	r14,[r5,-r2,LSL #2]!	@ r12= T[1]	T -= step
   1083 	LDR	r12,[r5,#4]		@ r14= T[0]
   1084 
   1085 	ADD	r6, r6, r10		@ r6 = s0 = w0[0] + w1[0]
   1086 	SUB	r10,r6, r10,LSL #1	@ r10= s1b= w0[0] - w1[0]
   1087 	SUB	r11,r11,r9		@ r11= s1 = w1[1] - w0[1]
   1088 	ADD	r9, r11,r9, LSL #1	@ r9 = s0b= w1[1] + w0[1]
   1089 
   1090 	@ Can save 1 cycle by using SMULL SMLAL - at the cost of being
   1091 	@ 1 off.
   1092 	SMULL	r0, r3, r6, r14		@ (r0,r3)   = s0*T[0]
   1093 	SMULL	r0, r4, r11,r12		@ (r0,r4)  += s1*T[1] = s2
   1094 	ADD	r3, r3, r4
   1095 	SMULL	r0, r14,r11,r14		@ (r0,r14)  = s1*T[0]
   1096 	SMULL	r0, r12,r6, r12		@ (r0,r12) += s0*T[1] = s3
   1097 	SUB	r14,r14,r12
   1098 
   1099 	@ r9 = s0b<<1
   1100 	@ r10= s1b<<1
   1101 	ADD	r9, r3, r9, ASR #1	@ r9 = s0b + s2
   1102 	SUB	r3, r9, r3, LSL #1	@ r3 = s0b - s2
   1103 
   1104 	SUB	r12,r14,r10,ASR #1	@ r12= s3  - s1b
   1105 	ADD	r10,r14,r10,ASR #1	@ r10= s3  + s1b
   1106 	STR	r9, [r1],#4
   1107 	STR	r10,[r1],#4		@ w0 += 2
   1108 	STR	r3, [r7]
   1109 	STR	r12,[r7,#4]
   1110 
   1111 	CMP	r1,r7
   1112 	BLT	step7_loop2
   1113 
   1114 	LDMFD	r13!,{r0-r3}
   1115 
   1116 	@ r0 = points
   1117 	@ r1 = in
   1118 	@ r2 = step
   1119 	@ r3 = shift
   1120 	MOV	r2, r2, ASR #2		@ r2 = step >>= 2
   1121 	CMP	r2, #0
   1122 	CMPNE	r2, #1
   1123 	BEQ	mdct_end
   1124 
   1125 	@ step > 1 (default case)
   1126 	CMP	r2, #4			@ r5 = T = (step>=4) ?
   1127 	ADR	r7, .Lsincos_lookup	@          sincos_lookup0 +
   1128 	ADDLT	r7, #4			@          sincos_lookup1
   1129 	LDR	r5, [r7]
   1130 	ADD	r5, r7
   1131 	ADD	r7, r1, r0, LSL #1	@ r7 = iX = x + (n>>1)
   1132 	ADDGE	r5, r5, r2, LSL #1	@		            (step>>1)
   1133 mdct_step8_default:
   1134 	LDR	r6, [r1],#4		@ r6 =  s0 = x[0]
   1135 	LDR	r8, [r1],#4		@ r8 = -s1 = x[1]
   1136 	LDR	r12,[r5,#4]       	@ r12= T[1]
   1137 	LDR	r14,[r5],r2,LSL #2	@ r14= T[0]	T += step
   1138 	RSB	r8, r8, #0		@ r8 = s1
   1139 
   1140 	@ XPROD31(s0, s1, T[0], T[1], x, x+1)
   1141 	@ x[0] = s0 * T[0] + s1 * T[1]      x[1] = s1 * T[0] - s0 * T[1]
   1142 	SMULL	r9, r10, r8, r12	@ (r9,r10)  = s1 * T[1]
   1143 	CMP	r1, r7
   1144 	SMLAL	r9, r10, r6, r14	@ (r9,r10) += s0 * T[0]
   1145 	RSB	r6, r6, #0		@ r6 = -s0
   1146 	SMULL	r9, r11, r8, r14	@ (r9,r11)  = s1 * T[0]
   1147 	MOV	r10,r10,LSL #1
   1148 	SMLAL	r9, r11, r6, r12	@ (r9,r11) -= s0 * T[1]
   1149 	STR	r10,[r1,#-8]
   1150 	MOV	r11,r11,LSL #1
   1151 	STR	r11,[r1,#-4]
   1152 	BLT	mdct_step8_default
   1153 
   1154 mdct_end:
   1155 	MOV	r0, r2
   1156 	LDMFD	r13!,{r4-r11,PC}
   1157 
   1158 cPI1_8:
   1159 	.word	0x7641af3d
   1160 cPI2_8:
   1161 	.word	0x5a82799a
   1162 cPI3_8:
   1163 	.word	0x30fbc54d
   1164 bitrev:
   1165 	.byte	0
   1166 	.byte	32
   1167 	.byte	16
   1168 	.byte	48
   1169 	.byte	8
   1170 	.byte	40
   1171 	.byte	24
   1172 	.byte	56
   1173 	.byte	4
   1174 	.byte	36
   1175 	.byte	20
   1176 	.byte	52
   1177 	.byte	12
   1178 	.byte	44
   1179 	.byte	28
   1180 	.byte	60
   1181 	.byte	2
   1182 	.byte	34
   1183 	.byte	18
   1184 	.byte	50
   1185 	.byte	10
   1186 	.byte	42
   1187 	.byte	26
   1188 	.byte	58
   1189 	.byte	6
   1190 	.byte	38
   1191 	.byte	22
   1192 	.byte	54
   1193 	.byte	14
   1194 	.byte	46
   1195 	.byte	30
   1196 	.byte	62
   1197 	.byte	1
   1198 	.byte	33
   1199 	.byte	17
   1200 	.byte	49
   1201 	.byte	9
   1202 	.byte	41
   1203 	.byte	25
   1204 	.byte	57
   1205 	.byte	5
   1206 	.byte	37
   1207 	.byte	21
   1208 	.byte	53
   1209 	.byte	13
   1210 	.byte	45
   1211 	.byte	29
   1212 	.byte	61
   1213 	.byte	3
   1214 	.byte	35
   1215 	.byte	19
   1216 	.byte	51
   1217 	.byte	11
   1218 	.byte	43
   1219 	.byte	27
   1220 	.byte	59
   1221 	.byte	7
   1222 	.byte	39
   1223 	.byte	23
   1224 	.byte	55
   1225 	.byte	15
   1226 	.byte	47
   1227 	.byte	31
   1228 	.byte	63
   1229 
   1230 .Lsincos_lookup:
   1231 	.word	sincos_lookup0-.Lsincos_lookup
   1232 	.word	sincos_lookup1-(.Lsincos_lookup+4)
   1233 
   1234 	@ END
   1235