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/* Copyright (C) 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include <endian.h>
/* void *memset(void *s, int c, size_t n).
This routine could be optimized further for MIPS64, but this is left
as an exercise for the future. When it is done, the file should be kept
as a sisterfile to this one, and placed in the sysdeps/mips/mips64
directory. */
#if __BYTE_ORDER == __BIG_ENDIAN
# define SWHI swl /* high part is left in big-endian */
#else
# define SWHI swr /* high part is right in little-endian */
#endif
ENTRY (memset)
.set noreorder
slti t1, a2, 8 # Less than 8?
bne t1, zero, $last8
move v0, a0 # Setup exit value before too late
beq a1, zero, $ueven # If zero pattern, no need to extend
andi a1, 0xff # Avoid problems with bogus arguments
sll t0, a1, 8
or a1, t0
sll t0, a1, 16
or a1, t0 # a1 is now pattern in full word
$ueven: subu t0, zero, a0 # Unaligned address?
andi t0, 0x3
beq t0, zero, $chkw
subu a2, t0
SWHI a1, 0(a0) # Yes, handle first unaligned part
addu a0, t0 # Now both a0 and a2 are updated
$chkw: andi t0, a2, 0x7 # Enough left for one loop iteration?
beq t0, a2, $chkl
subu a3, a2, t0
addu a3, a0 # a3 is last loop address +1
move a2, t0 # a2 is now # of bytes left after loop
$loopw: addiu a0, 8 # Handle 2 words pr. iteration
sw a1, -8(a0)
bne a0, a3, $loopw
sw a1, -4(a0)
$chkl: andi t0, a2, 0x4 # Check if there is at least a full
beq t0, zero, $last8 # word remaining after the loop
subu a2, t0
sw a1, 0(a0) # Yes...
addiu a0, 4
$last8: blez a2, $exit # Handle last 8 bytes (if cnt>0)
addu a3, a2, a0 # a3 is last address +1
$lst8l: addiu a0, 1
bne a0, a3, $lst8l
sb a1, -1(a0)
$exit: j ra # Bye, bye
nop
.set reorder
END (memset)
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