linux-sg2042/arch/avr32/lib/csum_partial.S

48 lines
892 B
ArmAsm

/*
* Copyright (C) 2004-2006 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.
*/
/*
* unsigned int csum_partial(const unsigned char *buff,
* int len, unsigned int sum)
*/
.text
.global csum_partial
.type csum_partial,"function"
.align 1
csum_partial:
/* checksum complete words, aligned or not */
3: sub r11, 4
brlt 5f
4: ld.w r9, r12++
add r10, r9
acr r10
sub r11, 4
brge 4b
/* return if we had a whole number of words */
5: sub r11, -4
reteq r10
/* checksum any remaining bytes at the end */
mov r9, 0
mov r8, 0
cp r11, 2
brlt 6f
ld.uh r9, r12++
sub r11, 2
breq 7f
lsl r9, 16
6: ld.ub r8, r12++
lsl r8, 8
7: or r9, r8
add r10, r9
acr r10
retal r10
.size csum_partial, . - csum_partial