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/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
Ported to mips3 n32/n64 by Alexandre Oliva <aoliva@redhat.com>
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>
#include <sys/asm.h>
/* void *memset(void *s, int c, size_t n);
This could probably be optimized further. */
#if __BYTE_ORDER == __BIG_ENDIAN
# define SDHI sdl /* high part is left in big-endian */
#else
# define SDHI sdr /* high part is right in little-endian */
#endif
ENTRY (memset)
.set noreorder
slti ta1, a2, 16 # Less than 16?
bne ta1, zero, L(last16)
move v0, a0 # Setup exit value before too late
beq a1, zero, L(ueven) # If zero pattern, no need to extend
andi a1, 0xff # Avoid problems with bogus arguments
dsll ta0, a1, 8
or a1, ta0
dsll ta0, a1, 16
or a1, ta0 # a1 is now pattern in full word
dsll ta0, a1, 32
or a1, ta0 # a1 is now pattern in double word
L(ueven):
PTR_SUBU ta0, zero, a0 # Unaligned address?
andi ta0, 0x7
beq ta0, zero, L(chkw)
PTR_SUBU a2, ta0
SDHI a1, 0(a0) # Yes, handle first unaligned part
PTR_ADDU a0, ta0 # Now both a0 and a2 are updated
L(chkw):
andi ta0, a2, 0xf # Enough left for one loop iteration?
beq ta0, a2, L(chkl)
PTR_SUBU a3, a2, ta0
PTR_ADDU a3, a0 # a3 is last loop address +1
move a2, ta0 # a2 is now # of bytes left after loop
L(loopw):
PTR_ADDIU a0, 16 # Handle 2 dwords pr. iteration
sd a1, -16(a0)
bne a0, a3, L(loopw)
sd a1, -8(a0)
L(chkl):
andi ta0, a2, 0x8 # Check if there is at least a double
beq ta0, zero, L(last16) # word remaining after the loop
PTR_SUBU a2, ta0
sd a1, 0(a0) # Yes...
PTR_ADDIU a0, 8
L(last16):
blez a2, L(exit) # Handle last 16 bytes (if cnt>0)
PTR_ADDU a3, a2, a0 # a3 is last address +1
L(lst16l):
PTR_ADDIU a0, 1
bne a0, a3, L(lst16l)
sb a1, -1(a0)
L(exit):
j ra # Bye, bye
nop
.set reorder
END (memset)
libc_hidden_builtin_def (memset)
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