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/* $OpenBSD: bzero.S,v 1.1 2004/08/11 10:29:59 pefo Exp $ */
#include "DEFS.h"
/*
* bzero(s1, n)
*/
LEAF(bzero)
ALEAF(blkclr)
.set noreorder
blt a1, 12, smallclr # small amount to clear?
subu a3, zero, a0 # compute # bytes to word align address
and a3, a3, 3
beq a3, zero, 1f # skip if word aligned
subu a1, a1, a3 # subtract from remaining count
SWHI zero, 0(a0) # clear 1, 2, or 3 bytes to align
addu a0, a0, a3
1:
and v0, a1, 3 # compute number of words left
subu a3, a1, v0
move a1, v0
addu a3, a3, a0 # compute ending address
2:
addu a0, a0, 4 # clear words
bne a0, a3, 2b # unrolling loop does not help
sw zero, -4(a0) # since we are limited by memory speed
smallclr:
ble a1, zero, 2f
addu a3, a1, a0 # compute ending address
1:
addu a0, a0, 1 # clear bytes
bne a0, a3, 1b
sb zero, -1(a0)
2:
j ra
nop
END(bzero)
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