735208a541
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7485 a1c6a512-1295-4272-9138-f99709370657
124 lines
4.8 KiB
ArmAsm
124 lines
4.8 KiB
ArmAsm
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2005 by Thom Johansen
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*
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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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/* this will also be the home to III_imdct_l in the future */
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.global III_imdct_s
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III_imdct_s:
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/* we need to save 9 registers and 36 samples of temp buffer */
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lea.l (-45*4, %sp), %sp
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movem.l %d2-%d7/%a2-%a4, (36*4, %sp)
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move.l (45*4 + 4, %sp), %a2 /* a2 = X */
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move.l %sp, %a3
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/* IMDCT */
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/* if additional precision is needed in this block, it is possible to
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* get more low bits out of the accext01 register _before_ doing the
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* movclrs.
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*/
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sub.l %a0, %a0 /* clear loop variable */
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.imdctloop: /* outer loop label */
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lea.l imdct_s, %a1 /* load pointer to imdct coefs in a1 */
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movem.l (%a2), %d0-%d5 /* load some input data in d0-d5 */
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lea.l (6*4, %a2), %a2
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clr.l %d7 /* clear loop variable */
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move.l (%a1)+, %a4 /* load imdct coef in a4 */
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.macloop: /* inner loop label */
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mac.l %d0, %a4, (%a1)+, %a4, %acc0 /* mac sequence */
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mac.l %d1, %a4, (%a1)+, %a4, %acc0
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mac.l %d2, %a4, (%a1)+, %a4, %acc0
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mac.l %d3, %a4, (%a1)+, %a4, %acc0
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mac.l %d4, %a4, (%a1)+, %a4, %acc0
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mac.l %d5, %a4, (%a1)+, %a4, %acc0
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movclr.l %acc0, %d6 /* get result, left shifted once */
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asl.l #3, %d6 /* one shift free, shift three more */
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move.l %d6, (%a3, %d7.l*4) /* yptr[i] = result */
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neg.l %d6
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neg.l %d7
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move.l %d6, (5*4, %a3, %d7.l*4) /* yptr[5 - i] = -result */
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mac.l %d0, %a4, (%a1)+, %a4, %acc0 /* mac sequence */
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mac.l %d1, %a4, (%a1)+, %a4, %acc0
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mac.l %d2, %a4, (%a1)+, %a4, %acc0
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mac.l %d3, %a4, (%a1)+, %a4, %acc0
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mac.l %d4, %a4, (%a1)+, %a4, %acc0
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mac.l %d5, %a4, (%a1)+, %a4, %acc0
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movclr.l %acc0, %d6 /* get result */
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asl.l #3, %d6
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move.l %d6, (11*4, %a3, %d7.l*4) /* yptr[11 - i] = result */
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neg.l %d7
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move.l %d6, (6*4, %a3, %d7.l*4) /* yptr[i + 6] = result */
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addq.l #1, %d7 /* increment inner loop variable */
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moveq.l #3, %d6
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cmp.l %d6, %d7 /* we do three inner loop iterations */
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jne .macloop
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lea.l (12*4, %a3), %a3 /* add pointer increment */
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addq.l #1, %a0 /* increment outer loop variable */
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moveq.l #3, %d0
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cmp.l %d0, %a0 /* we do three outer loop iterations */
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jne .imdctloop
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/* windowing, overlapping and concatenation */
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move.l (45*4 + 8, %sp), %a2 /* a2 = z */
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move.l %sp, %a3 /* a3 = tmp buffer ptr */
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lea.l window_s, %a4 /* a4 = window coef pointer */
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moveq.l #6, %d7 /* six iterations */
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.overlaploop:
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clr.l (%a2) /* z[i + 0] = 0 */
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move.l (%a4), %d0
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move.l (%a3), %d2
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mac.l %d0, %d2, (6*4, %a4), %d1, %acc0
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move.l (6*4, %a3), %d2
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movclr.l %acc0, %d6
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asl.l #3, %d6
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move.l %d6, (6*4, %a2) /* z[i + 6] = result */
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mac.l %d1, %d2, (12*4, %a3), %d2, %acc0
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mac.l %d0, %d2, (18*4, %a3), %d2, %acc0
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movclr.l %acc0, %d6
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asl.l #3, %d6
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move.l %d6, (12*4, %a2) /* z[i + 12] = result */
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mac.l %d1, %d2, (24*4, %a3), %d2, %acc0
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mac.l %d0, %d2, (30*4, %a3), %d2, %acc0
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movclr.l %acc0, %d6
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asl.l #3, %d6
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move.l %d6, (18*4, %a2) /* z[i + 18] = result */
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mac.l %d1, %d2, %acc0
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movclr.l %acc0, %d6
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asl.l #3, %d6
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move.l %d6, (24*4, %a2) /* z[i + 24] = result */
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clr.l (30*4, %a2) /* z[i + 30] = 0 */
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addq.l #4, %a2 /* increment all pointers */
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addq.l #4, %a3
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addq.l #4, %a4
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subq.l #1, %d7 /* decrement loop counter */
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jne .overlaploop
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/* fall through to exit if we're done */
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/* clean up */
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movem.l (36*4, %sp), %d2-%d7/%a2-%a4
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lea.l (45*4, %sp), %sp
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rts
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