rockbox/apps/plugins/mpegplayer/idct_arm.S

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2007 by Michael Sevakis
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

    .global     mpeg2_idct_copy
    .type       mpeg2_idct_copy, %function
    .global     mpeg2_idct_add
    .type       mpeg2_idct_add, %function


/* Custom calling convention:
 * r0 contains block pointer and is non-volatile
 * all non-volatile c context saved and restored on its behalf
 */
.idct:
    add    r12, r0, #128
1:
    ldrsh  r1, [r0, #0]           /* d0 */
    ldrsh  r2, [r0, #2]           /* d1 */
    ldrsh  r3, [r0, #4]           /* d2 */
    ldrsh  r4, [r0, #6]           /* d3 */
    ldrsh  r5, [r0, #8]           /* d0 */
    ldrsh  r6, [r0, #10]          /* d1 */
    ldrsh  r7, [r0, #12]          /* d2 */
    ldrsh  r8, [r0, #14]          /* d3 */
    orrs   r9, r2, r3
    orreqs r9, r4, r5
    orreqs r9, r6, r7
    cmpeq  r8, #0
    bne    2f
    mov    r1, r1, asl #15
    bic    r1, r1, #0x8000
    orr    r1, r1, r1, lsr #16
    str    r1, [r0], #4
    str    r1, [r0], #4
    str    r1, [r0], #4
    str    r1, [r0], #4
    cmp    r0, r12
    blo    1b
    b      3f
2:
    mov    r1, r1, asl #11        /* r1 = d0 = (block[0] << 11) + 2048 */
    add    r1, r1, #2048
    add    r1, r1, r3, asl #11    /* r1 = t0 = d0 + (block[2] << 11) */
    sub    r3, r1, r3, asl #12    /* r3 = t1 = d0 - (block[2] << 11) */

    add    r9, r2, r4             /* r9 = tmp = (d1+d3)*(1108/4) */
    add    r10, r9, r9, asl #2
    add    r10, r10, r9, asl #4
    add    r9, r10, r9, asl #8

    add    r10, r2, r2, asl #4    /* r2 = t2 = tmp + (d1*(1568/32)*8) */
    add    r2, r10, r2, asl #5
    add    r2, r9, r2, asl #3

    add    r10, r4, r4, asl #2    /* r4 = t3 = tmp - (d3*(3784/8)*2) */
    rsb    r10, r10, r4, asl #6
    add    r4, r4, r10, asl #3
    sub    r4, r9, r4, asl #1
    /* t2 & t3 are 1/4 final value here */
    add    r1, r1, r2, asl #2     /* r1 = a0 = t0 + t2 */
    sub    r2, r1, r2, asl #3     /* r2 = a3 = t0 - t2 */
    add    r3, r3, r4, asl #2     /* r3 = a1 = t1 + t3 */
    sub    r4, r3, r4, asl #3     /* r4 = a2 = t1 - t3 */

    add    r9, r8, r5             /* r9 = tmp = 565*(d3 + d0) */
    add    r10, r9, r9, asl #4
    add    r10, r10, r10, asl #5
    add    r9, r10, r9, asl #2

    add    r10, r5, r5, asl #4    /* r5 = t0 = tmp + (((2276/4)*d0)*4) */
    add    r10, r10, r10, asl #5
    add    r5, r10, r5, asl #3
    add    r5, r9, r5, asl #2

    add    r10, r8, r8, asl #2    /* r8 = t1 = tmp - (((3406/2)*d3)*2) */
    add    r10, r10, r10, asl #4
    add    r10, r10, r8, asl #7
    rsb    r8, r8, r10, asl #3
    sub    r8, r9, r8, asl #1

    add    r9, r6, r7             /* r9 = tmp = (2408/8)*(d1 + d2) */
    add    r10, r9, r9, asl #3
    add    r10, r10, r10, asl #5
    add    r9, r10, r9, asl #2

    add    r10, r7, r7, asl #3    /* r7 = t2 = (tmp*8) - 799*d2 */
    add    r10, r10, r7, asl #4
    rsb    r7, r7, r10, asl #5
    rsb    r7, r7, r9, asl #3

    sub    r10, r6, r6, asl #4    /* r6 = t3 = (tmp*8) - 4017*d1 */
    sub    r10, r10, r6, asl #6
    add    r10, r10, r6, asl #12
    add    r6, r10, r6
    rsb    r6, r6, r9, asl #3
    /* t0 = r5, t1 = r8, t2 = r7, t3 = r6*/
    add    r9, r5, r7             /* r9 = b0 = t0 + t2 */
    add    r10, r8, r6            /* r10 = b3 = t1 + t3 */
    sub    r5, r5, r7             /* t0 -= t2 */
    sub    r8, r8, r6             /* t1 -= t3 */
    add    r6, r5, r8             /* r6 = t0 + t1 */
    sub    r7, r5, r8             /* r7 = t0 - t1 */

    add    r11, r6, r6, asr #2    /* r6 = b1 = r6*(181/128) */
    add    r11, r11, r11, asr #5
    add    r6, r11, r6, asr #3
    add    r11, r7, r7, asr #2    /* r7 = b2 = r7*(181/128) */
    add    r11, r11, r11, asr #5
    add    r7, r11, r7, asr #3
    /* r1 = a0, r3 = a1,   r4 = a2,   r2 = a3 */
    /* r9 = b0, r6 = b1*2, r7 = b2*2, r10 = b3 */
    add    r5, r1, r9             /* block[0] = (a0 + b0) >> 12 */
    mov    r5, r5, asr #12
    strh   r5, [r0], #2
    add    r8, r3, r6, asr #1     /* block[1] = (a1 + b1) >> 12 */
    mov    r8, r8, asr #12
    strh   r8, [r0], #2
    add    r5, r4, r7, asr #1     /* block[2] = (a2 + b2) >> 12 */
    mov    r5, r5, asr #12
    strh   r5, [r0], #2
    add    r8, r2, r10            /* block[3] = (a3 + b3) >> 12 */
    mov    r8, r8, asr #12
    strh   r8, [r0], #2
    sub    r5, r2, r10            /* block[4] = (a3 - b3) >> 12 */
    mov    r5, r5, asr #12
    strh   r5, [r0], #2
    sub    r8, r4, r7, asr #1     /* block[5] = (a2 - b2) >> 12 */
    mov    r8, r8, asr #12
    strh   r8, [r0], #2
    sub    r5, r3, r6, asr #1     /* block[6] = (a1 - b1) >> 12 */
    mov    r5, r5, asr #12
    strh   r5, [r0], #2
    sub    r8, r1, r9             /* block[7] = (a0 - b0) >> 12 */
    mov    r8, r8, asr #12
    strh   r8, [r0], #2
    cmp    r0, r12
    blo    1b
3:
    sub    r0, r0, #128
    add    r12, r0, #16
4:
    ldrsh  r1, [r0, #0*8]         /* d0 */
    ldrsh  r2, [r0, #2*8]         /* d1 */
    ldrsh  r3, [r0, #4*8]         /* d2 */
    ldrsh  r4, [r0, #6*8]         /* d3 */
    ldrsh  r5, [r0, #8*8]         /* d0 */
    ldrsh  r6, [r0, #10*8]        /* d1 */
    ldrsh  r7, [r0, #12*8]        /* d2 */
    ldrsh  r8, [r0, #14*8]        /* d3 */

    mov    r1, r1, asl #11        /* r1 = d0 = (block[0] << 11) + 2048 */
    add    r1, r1, #65536
    add    r1, r1, r3, asl #11    /* r1 = t0 = d0 + d2:(block[2] << 11) */
    sub    r3, r1, r3, asl #12    /* r3 = t1 = d0 - d2:(block[2] << 11) */

    add    r9, r2, r4             /* r9 = tmp = (d1+d3)*(1108/4) */
    add    r10, r9, r9, asl #2
    add    r10, r10, r9, asl #4
    add    r9, r10, r9, asl #8

    add    r11, r2, r2, asl #4    /* r2 = t2 = tmp + (d1*(1568/32)*8) */
    add    r2, r11, r2, asl #5
    add    r2, r9, r2, asl #3

    add    r10, r4, r4, asl #2    /* r4 = t3 = tmp - (d3*(3784/8)*2) */
    rsb    r10, r10, r4, asl #6
    add    r4, r4, r10, asl #3
    sub    r4, r9, r4, asl #1
    /* t2 & t3 are 1/4 final value here */
    add    r1, r1, r2, asl #2     /* r1 = a0 = t0 + t2 */
    sub    r2, r1, r2, asl #3     /* r2 = a3 = t0 - t2 */
    add    r3, r3, r4, asl #2     /* r3 = a1 = t1 + t3 */
    sub    r4, r3, r4, asl #3     /* r4 = a2 = t1 - t3 */

    add    r9, r8, r5             /* r9 = tmp = 565*(d3 + d0) */
    add    r10, r9, r9, asl #4
    add    r10, r10, r10, asl #5
    add    r9, r10, r9, asl #2

    add    r10, r5, r5, asl #4    /* r5 = t0 = tmp + (((2276/4)*d0)*4) */
    add    r10, r10, r10, asl #5
    add    r5, r10, r5, asl #3
    add    r5, r9, r5, asl #2

    add    r10, r8, r8, asl #2    /* r8 = t1 = tmp - (((3406/2)*d3)*2) */
    add    r10, r10, r10, asl #4
    add    r10, r10, r8, asl #7
    rsb    r8, r8, r10, asl #3
    sub    r8, r9, r8, asl #1

    add    r9, r6, r7             /* r9 = tmp = (2408/8)*(d1 + d2) */
    add    r10, r9, r9, asl #3
    add    r10, r10, r10, asl #5
    add    r9, r10, r9, asl #2

    add    r10, r7, r7, asl #3    /* r7 = t2 = (tmp*8) - 799*d2 */
    add    r10, r10, r7, asl #4
    rsb    r7, r7, r10, asl #5
    rsb    r7, r7, r9, asl #3

    sub    r10, r6, r6, asl #4    /* r6 = t3 = (tmp*8) - 4017*d1 */
    sub    r10, r10, r6, asl #6
    add    r10, r10, r6, asl #12
    add    r6, r10, r6
    rsb    r6, r6, r9, asl #3
                                    /* t0=r5, t1=r8, t2=r7, t3=r6*/
    add    r9, r5, r7             /* r9 = b0 = t0 + t2 */
    add    r10, r8, r6            /* r10 = b3 = t1 + t3 */
    sub    r5, r5, r7             /* t0 -= t2 */
    sub    r8, r8, r6             /* t1 -= t3 */
    add    r6, r5, r8             /* r6 = t0 + t1 */
    sub    r7, r5, r8             /* r7 = t0 - t1 */

    add    r11, r6, r6, asr #2    /* r6 = b1 = r5*(181/128) */
    add    r11, r11, r11, asr #5
    add    r6, r11, r6, asr #3
    add    r11, r7, r7, asr #2    /* r7 = b2 = r6*(181/128) */
    add    r11, r11, r11, asr #5
    add    r7, r11, r7, asr #3
    /* r1 = a0, r3 = a1,   r4 = a2,    r2 = a3 */
    /* r9 = b0, r6 = b1*2, r7 = b2*2, r10 = b3 */
    add    r5, r1, r9             /* block[0] = (a0 + b0) >> 17 */
    mov    r5, r5, asr #17
    strh   r5, [r0, #0*8]
    add    r8, r3, r6, asr #1     /* block[1] = (a1 + b1) >> 17 */
    mov    r8, r8, asr #17
    strh   r8, [r0, #2*8]
    add    r5, r4, r7, asr #1     /* block[2] = (a2 + b2) >> 17 */
    mov    r5, r5, asr #17
    strh   r5, [r0, #4*8]
    add    r8, r2, r10            /* block[3] = (a3 + b3) >> 17 */
    mov    r8, r8, asr #17
    strh   r8, [r0, #6*8]
    sub    r5, r2, r10            /* block[4] = (a3 - b3) >> 17 */
    mov    r5, r5, asr #17
    strh   r5, [r0, #8*8]
    sub    r8, r4, r7, asr #1     /* block[5] = (a2 - b2) >> 17 */
    mov    r8, r8, asr #17
    strh   r8, [r0, #10*8]
    sub    r5, r3, r6, asr #1     /* block[6] = (a1 - b1) >> 17 */
    mov    r5, r5, asr #17
    strh   r5, [r0, #12*8]
    sub    r8, r1, r9             /* block[7] = (a0 - b0) >> 17 */
    mov    r8, r8, asr #17
    strh   r8, [r0, #14*8]
    add    r0, r0, #2
    cmp    r0, r12
    blo    4b
    sub    r0, r0, #16
    bx     lr

mpeg2_idct_copy:
    stmfd  sp!, { r1-r2, r4-r12, lr }
    bl     .idct
    ldmfd  sp!, { r1-r2 }
    mov    r11, #0
    add    r12, r0, #128
1:
    ldrsh  r3, [r0, #0]
    ldrsh  r4, [r0, #2]
    ldrsh  r5, [r0, #4]
    ldrsh  r6, [r0, #6]
    ldrsh  r7, [r0, #8]
    ldrsh  r8, [r0, #10]
    ldrsh  r9, [r0, #12]
    ldrsh  r10, [r0, #14]
    cmp    r3, #255
    mvnhi  r3, r3, asr #31
    strb   r3, [r1, #0]
    str    r11, [r0], #4
    cmp    r4, #255
    mvnhi  r4, r4, asr #31
    strb   r4, [r1, #1]
    cmp    r5, #255
    mvnhi  r5, r5, asr #31
    strb   r5, [r1, #2]
    str    r11, [r0], #4
    cmp    r6, #255
    mvnhi  r6, r6, asr #31
    strb   r6, [r1, #3]
    cmp    r7, #255
    mvnhi  r7, r7, asr #31
    strb   r7, [r1, #4]
    str    r11, [r0], #4
    cmp    r8, #255
    mvnhi  r8, r8, asr #31
    strb   r8, [r1, #5]
    cmp    r9, #255
    mvnhi  r9, r9, asr #31
    strb   r9, [r1, #6]
    str    r11, [r0], #4
    cmp    r10, #255
    mvnhi  r10, r10, asr #31
    strb   r10, [r1, #7]
    add    r1, r1, r2
    cmp    r0, r12
    blo    1b
    ldmfd  sp!, { r4-r12, pc }

mpeg2_idct_add:
    cmp    r0, #129
    mov    r0, r1
    ldreqsh r1, [r0, #0]
    bne    1f
    and    r1, r1, #0x70
    cmp    r1, #0x40
    bne    3f
1:
    stmfd  sp!, { r2-r12, lr }
    bl     .idct
    ldmfd  sp!, { r1-r2 }
    mov    r11, #0
    add    r12, r0, #128
2:
    ldrb   r3, [r1, #0]
    ldrb   r4, [r1, #1]
    ldrb   r5, [r1, #2]
    ldrb   r6, [r1, #3]
    ldrsh  r7, [r0, #0]
    ldrsh  r8, [r0, #2]
    ldrsh  r9, [r0, #4]
    ldrsh  r10, [r0, #6]
    add    r7, r7, r3
    ldrb   r3, [r1, #4]
    cmp    r7, #255
    mvnhi  r7, r7, asr #31
    strb   r7, [r1, #0]
    ldrsh  r7, [r0, #8]
    add    r8, r8, r4
    ldrb   r4, [r1, #5]
    cmp    r8, #255
    mvnhi  r8, r8, asr #31
    strb   r8, [r1, #1]
    ldrsh  r8, [r0, #10]
    add    r9, r9, r5
    ldrb   r5, [r1, #6]
    cmp    r9, #255
    mvnhi  r9, r9, asr #31
    strb   r9, [r1, #2]
    ldrsh  r9, [r0, #12]
    add    r10, r10, r6
    ldrb   r6, [r1, #7]
    cmp    r10, #255
    mvnhi  r10, r10, asr #31
    strb   r10, [r1, #3]
    ldrsh  r10, [r0, #14]
    str    r11, [r0], #4
    add    r7, r7, r3
    cmp    r7, #255
    mvnhi  r7, r7, asr #31
    strb   r7, [r1, #4]
    str    r11, [r0], #4
    add    r8, r8, r4
    cmp    r8, #255
    mvnhi  r8, r8, asr #31
    strb   r8, [r1, #5]
    str    r11, [r0], #4
    add    r9, r9, r5
    cmp    r9, #255
    mvnhi  r9, r9, asr #31
    strb   r9, [r1, #6]
    add    r10, r10, r6
    cmp    r10, #255
    mvnhi  r10, r10, asr #31
    strb   r10, [r1, #7]
    str    r11, [r0], #4
    add    r1, r1, r2
    cmp    r0, r12
    blo    2b
    ldmfd  sp!, { r4-r12, pc }
3:
    stmfd  sp!, { r4-r11 }
    ldrsh  r1, [r0, #0]           /* r1 = block[0] */
    mov    r11, #0
    strh   r11, [r0, #0]          /* block[0] = 0 */
    strh   r11, [r0, #126]        /* block[63] = 0 */
    add    r1, r1, #64            /* r1 = DC << 7 */
    add    r0, r2, r3, asl #3
4:
    ldrb   r4, [r2, #0]
    ldrb   r5, [r2, #1]
    ldrb   r6, [r2, #2]
    ldrb   r7, [r2, #3]
    ldrb   r8, [r2, #4]
    ldrb   r9, [r2, #5]
    ldrb   r10, [r2, #6]
    ldrb   r11, [r2, #7]
    add    r4, r4, r1, asr #7
    cmp    r4, #255
    mvnhi  r4, r4, asr #31
    strb   r4, [r2, #0]
    add    r5, r5, r1, asr #7
    cmp    r5, #255
    mvnhi  r5, r5, asr #31
    strb   r5, [r2, #1]
    add    r6, r6, r1, asr #7
    cmp    r6, #255
    mvnhi  r6, r6, asr #31
    strb   r6, [r2, #2]
    add    r7, r7, r1, asr #7
    cmp    r7, #255
    mvnhi  r7, r7, asr #31
    strb   r7, [r2, #3]
    add    r8, r8, r1, asr #7
    cmp    r8, #255
    mvnhi  r8, r8, asr #31
    strb   r8, [r2, #4]
    add    r9, r9, r1, asr #7
    cmp    r9, #255
    mvnhi  r9, r9, asr #31
    strb   r9, [r2, #5]
    add    r10, r10, r1, asr #7
    cmp    r10, #255
    mvnhi  r10, r10, asr #31
    strb   r10, [r2, #6]
    add    r11, r11, r1, asr #7
    cmp    r11, #255
    mvnhi  r11, r11, asr #31
    strb   r11, [r2, #7]
    add    r2, r2, r3
    cmp    r2, r0
    blo    4b
    ldmfd  sp!, { r4-r11 }
    bx     lr