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Diffstat (limited to 'firmware/target/sh/bitswap.S')
| -rw-r--r-- | firmware/target/sh/bitswap.S | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/firmware/target/sh/bitswap.S b/firmware/target/sh/bitswap.S deleted file mode 100644 index ba8dd0cc1a..0000000000 --- a/firmware/target/sh/bitswap.S +++ /dev/null @@ -1,152 +0,0 @@ -/*************************************************************************** - * __________ __ ___. - * Open \______ \ ____ ____ | | _\_ |__ _______ ___ - * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / - * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < - * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ - * \/ \/ \/ \/ \/ - * $Id$ - * - * Copyright (C) 2004 by Jens Arnold - * - * 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. - * - ****************************************************************************/ - - .section .icode,"ax",@progbits - .align 2 - .global _bitswap - .type _bitswap,@function - -/* Flips the bits of all bytes in a memory area (required for mp3 data on - * the Archos). This version is optimized for speed and size. - * - * arguments: - * r4 - start address - * r5 - length - * - * return value: void - * - * register usage: - * r0 - temporary - * r1 - bit mask for rounding to long bound / low byte (after swap) - * r2 - high byte (after swap) / combined result - * r4 - data address - 4 - * r5 - end address - 4 - * r7 - flip table (addressing with signed offset) - * - * The instruction order below is devised in a way to utilize the pipelining - * of the SH1 to the max. - */ - -_bitswap: - mova _fliptable,r0 - mov r0,r7 - add #-4,r4 /* address is shifted by 4 */ - add r4,r5 /* r5 = end_address - 4 */ - cmp/hi r4,r5 /* at least something to do? */ - bf .exit /* no, get out of here! */ - - add #-3,r5 /* end offset for flipping 4 bytes per pass */ - mov r4,r0 - tst #1,r0 /* even address? */ - bt .start2_w /* yes, jump into main loop */ - - /* no, flip first byte */ - mov.b @(4,r4),r0 /* load byte, sign extension! */ - add #1,r4 /* early increment */ - mov.b @(r0,r7),r0 /* fliptable offset is signed */ - bra .start2_w /* jump into main loop */ - mov.b r0,@(3,r4) /* store byte */ - - /* main loop: flips 2 words per pass */ - .align 2 -.loop2_w: - mov.w @(6,r4),r0 /* load second word */ - add #4,r4 /* early increment */ - swap.b r0,r2 /* get high byte (2nd word) */ - exts.b r0,r0 /* prepare low byte (2nd word) */ - mov.b @(r0,r7),r1 /* swap low byte (2nd word) */ - exts.b r2,r0 /* prepare high byte (2nd word) */ - mov.b @(r0,r7),r2 /* swap high byte (2nd word) */ - extu.b r1,r0 /* zero extend low byte (2nd word) */ - mov.w @r4,r1 /* load first word */ - shll8 r2 /* shift high byte (2nd word), low byte zeroed */ - or r2,r0 /* put low byte (2nd word) in result */ - swap.b r1,r2 /* get high byte (1st word) */ - mov.w r0,@(2,r4) /* store result (2nd word) */ - exts.b r1,r0 /* prepare low byte (1st word) */ - mov.b @(r0,r7),r1 /* swap low byte (1st word) */ - exts.b r2,r0 /* prepare high byte (1st word) */ - mov.b @(r0,r7),r2 /* swap high byte (1st word) */ - extu.b r1,r0 /* zero extend low byte (1st word) */ - shll8 r2 /* shift high byte (1st word), low byte zeroed */ - or r2,r0 /* put low byte (1st word) in result */ - mov.w r0,@r4 /* store result (1st word) */ -.start2_w: - cmp/hi r4,r5 /* runs r4 up to last long bound */ - bt .loop2_w - - bra .start_b2 /* jump into trailing byte loop */ - add #3,r5 /* reset end offset */ - - /* trailing byte loop: flips 0..3 bytes */ -.loop_b2: - mov.b @(4,r4),r0 /* loand byte, sign extension! */ - add #1,r4 /* early increment */ - mov.b @(r0,r7),r0 /* fliptable offset is signed */ - mov.b r0,@(3,r4) /* store byte */ -.start_b2: - cmp/hi r4,r5 /* runs r4 up to end address */ - bt .loop_b2 - -.exit: - rts - nop - - .align 2 - .global _fliptable - - .byte 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1 - .byte 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1 - .byte 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9 - .byte 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9 - .byte 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5 - .byte 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5 - .byte 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed - .byte 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd - .byte 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3 - .byte 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3 - .byte 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb - .byte 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb - .byte 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7 - .byte 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7 - .byte 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef - .byte 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff -_fliptable: - .byte 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0 - .byte 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0 - .byte 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8 - .byte 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8 - .byte 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4 - .byte 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4 - .byte 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec - .byte 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc - .byte 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2 - .byte 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2 - .byte 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea - .byte 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa - .byte 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6 - .byte 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6 - .byte 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee - .byte 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe - - -.end: - .size _bitswap,.end-_bitswap |