findbit.S
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/*
* Copyright (C) 2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
.text
/*
* unsigned long find_first_zero_bit(const unsigned long *addr,
* unsigned long size)
*/
ENTRY(find_first_zero_bit)
cp.w r11, 0
reteq r11
mov r9, r11
1: ld.w r8, r12[0]
com r8
brne .L_found
sub r12, -4
sub r9, 32
brgt 1b
retal r11
/*
* unsigned long find_next_zero_bit(const unsigned long *addr,
* unsigned long size,
* unsigned long offset)
*/
ENTRY(find_next_zero_bit)
lsr r8, r10, 5
sub r9, r11, r10
retle r11
lsl r8, 2
add r12, r8
andl r10, 31, COH
breq 1f
/* offset is not word-aligned. Handle the first (32 - r10) bits */
ld.w r8, r12[0]
com r8
sub r12, -4
lsr r8, r8, r10
brne .L_found
/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
add r9, r10
sub r9, 32
retle r11
/* Main loop. offset must be word-aligned */
1: ld.w r8, r12[0]
com r8
brne .L_found
sub r12, -4
sub r9, 32
brgt 1b
retal r11
/* Common return path for when a bit is actually found. */
.L_found:
brev r8
clz r10, r8
rsub r9, r11
add r10, r9
/* XXX: If we don't have to return exactly "size" when the bit
is not found, we may drop this "min" thing */
min r12, r11, r10
retal r12
/*
* unsigned long find_first_bit(const unsigned long *addr,
* unsigned long size)
*/
ENTRY(find_first_bit)
cp.w r11, 0
reteq r11
mov r9, r11
1: ld.w r8, r12[0]
cp.w r8, 0
brne .L_found
sub r12, -4
sub r9, 32
brgt 1b
retal r11
/*
* unsigned long find_next_bit(const unsigned long *addr,
* unsigned long size,
* unsigned long offset)
*/
ENTRY(find_next_bit)
lsr r8, r10, 5
sub r9, r11, r10
retle r11
lsl r8, 2
add r12, r8
andl r10, 31, COH
breq 1f
/* offset is not word-aligned. Handle the first (32 - r10) bits */
ld.w r8, r12[0]
sub r12, -4
lsr r8, r8, r10
brne .L_found
/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
add r9, r10
sub r9, 32
retle r11
/* Main loop. offset must be word-aligned */
1: ld.w r8, r12[0]
cp.w r8, 0
brne .L_found
sub r12, -4
sub r9, 32
brgt 1b
retal r11
ENTRY(find_next_bit_le)
lsr r8, r10, 5
sub r9, r11, r10
retle r11
lsl r8, 2
add r12, r8
andl r10, 31, COH
breq 1f
/* offset is not word-aligned. Handle the first (32 - r10) bits */
ldswp.w r8, r12[0]
sub r12, -4
lsr r8, r8, r10
brne .L_found
/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
add r9, r10
sub r9, 32
retle r11
/* Main loop. offset must be word-aligned */
1: ldswp.w r8, r12[0]
cp.w r8, 0
brne .L_found
sub r12, -4
sub r9, 32
brgt 1b
retal r11
ENTRY(find_next_zero_bit_le)
lsr r8, r10, 5
sub r9, r11, r10
retle r11
lsl r8, 2
add r12, r8
andl r10, 31, COH
breq 1f
/* offset is not word-aligned. Handle the first (32 - r10) bits */
ldswp.w r8, r12[0]
sub r12, -4
com r8
lsr r8, r8, r10
brne .L_found
/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
add r9, r10
sub r9, 32
retle r11
/* Main loop. offset must be word-aligned */
1: ldswp.w r8, r12[0]
com r8
brne .L_found
sub r12, -4
sub r9, 32
brgt 1b
retal r11