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authorThomas Martitz <kugel@rockbox.org>2012-01-08 00:22:58 +0100
committerThomas Martitz <kugel@rockbox.org>2012-01-22 18:46:45 +0100
commitc94cf3b8885c8a9e192b95125ce4b8470a1aa3c3 (patch)
tree6ca83258616b00428b58e1e31c10dce020fbc310 /firmware/target/coldfire
parent5e9b62cd8ad4d38c7ca43c916b5bc831454bc267 (diff)
downloadrockbox-c94cf3b8885c8a9e192b95125ce4b8470a1aa3c3.tar.gz
rockbox-c94cf3b8885c8a9e192b95125ce4b8470a1aa3c3.zip
Move optimized ffs to firmware/asm, using the new automatic-asm-picking infrastructure.
Change-Id: I5e7bdc8be7de50ef604c16078857fff1b84650dc
Diffstat (limited to 'firmware/target/coldfire')
-rw-r--r--firmware/target/coldfire/ffs-coldfire.S65
1 files changed, 0 insertions, 65 deletions
diff --git a/firmware/target/coldfire/ffs-coldfire.S b/firmware/target/coldfire/ffs-coldfire.S
deleted file mode 100644
index 40a7297802..0000000000
--- a/firmware/target/coldfire/ffs-coldfire.S
+++ /dev/null
@@ -1,65 +0,0 @@
-/***************************************************************************
- * __________ __ ___.
- * Open \______ \ ____ ____ | | _\_ |__ _______ ___
- * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
- * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
- * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
- * \/ \/ \/ \/ \/
- * $Id$
- *
- * Copyright (C) 2008 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.
- *
- ****************************************************************************/
- #include "config.h"
-
-/****************************************************************************
- * int find_first_set_bit(uint32_t val);
- *
- * Find the index of the least significant set bit in the 32-bit word.
- *
- * return values:
- * 0 - bit 0 is set
- * 1 - bit 1 is set
- * ...
- * 31 - bit 31 is set
- * 32 - no bits set
- ****************************************************************************/
- .text
- .align 2
- .global find_first_set_bit
- .type find_first_set_bit,@function
-find_first_set_bit:
- | this is a coldfire version of the ffs algorithm devised by D.Seal
- | and posted to comp.sys.arm on 16 Feb 1994.
- |
- | Output modified to suit rockbox purposes.
-
- | Standard trick to isolate bottom bit in r0 or 0 if r0 = 0 on entry
- move.l 4(%sp), %d1 | %d1 = %d1 & -%d1
- lea.l L_ffs_table, %a0 | %a0 = table address
- move.l %d1, %d0 |
- neg.l %d1 |
- and.l %d0, %d1 |
-
- | now %d1 has at most one set bit, call this X
-
- move.l #0x0450fbaf, %d0 | %d0 = multiplier
- mulu.l %d0, %d1 | %d1 = X * 0x0450fbaf
-
- | now lookup in table indexed on top 6 bits of %d0
- moveq.l #26, %d0 | %d0 = final shift count
- lsr.l %d0, %d1 |
-
- | the top 24 bits of d0 are 0 so just load the value over it
- move.b (%a0, %d1.l), %d0 |
- rts |
-
- .size find_first_set_bit, .-find_first_set_bit