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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 *memcpy(void *s1, const void *s2, size_t n);
This could probably be optimized further. */
#if __BYTE_ORDER == __BIG_ENDIAN
# define LDHI ldl /* high part is left in big-endian */
# define SDHI sdl /* high part is left in big-endian */
# define LDLO ldr /* low part is right in big-endian */
# define SDLO sdr /* low part is right in big-endian */
#else
# define LDHI ldr /* high part is right in little-endian */
# define SDHI sdr /* high part is right in little-endian */
# define LDLO ldl /* low part is left in little-endian */
# define SDLO sdl /* low part is left in little-endian */
#endif
ENTRY (memcpy)
.set noreorder
slti t0, a2, 16 # Less than 16?
bne t0, zero, L(last16)
move v0, a0 # Setup exit value before too late
xor t0, a1, a0 # Find a0/a1 displacement
andi t0, 0x7
bne t0, zero, L(shift) # Go handle the unaligned case
PTR_SUBU t1, zero, a1
andi t1, 0x7 # a0/a1 are aligned, but are we
beq t1, zero, L(chk8w) # starting in the middle of a word?
PTR_SUBU a2, t1
LDHI t0, 0(a1) # Yes we are... take care of that
PTR_ADDU a1, t1
SDHI t0, 0(a0)
PTR_ADDU a0, t1
L(chk8w):
andi t0, a2, 0x3f # 64 or more bytes left?
beq t0, a2, L(chk1w)
PTR_SUBU a3, a2, t0 # Yes
PTR_ADDU a3, a1 # a3 = end address of loop
move a2, t0 # a2 = what will be left after loop
L(lop8w):
ld t0, 0(a1) # Loop taking 8 words at a time
ld t1, 8(a1)
ld t2, 16(a1)
ld t3, 24(a1)
ld ta0, 32(a1)
ld ta1, 40(a1)
ld ta2, 48(a1)
ld ta3, 56(a1)
PTR_ADDIU a0, 64
PTR_ADDIU a1, 64
sd t0, -64(a0)
sd t1, -56(a0)
sd t2, -48(a0)
sd t3, -40(a0)
sd ta0, -32(a0)
sd ta1, -24(a0)
sd ta2, -16(a0)
bne a1, a3, L(lop8w)
sd ta3, -8(a0)
L(chk1w):
andi t0, a2, 0x7 # 8 or more bytes left?
beq t0, a2, L(last16)
PTR_SUBU a3, a2, t0 # Yes, handle them one dword at a time
PTR_ADDU a3, a1 # a3 again end address
move a2, t0
L(lop1w):
ld t0, 0(a1)
PTR_ADDIU a0, 8
PTR_ADDIU a1, 8
bne a1, a3, L(lop1w)
sd t0, -8(a0)
L(last16):
blez a2, L(lst16e) # Handle last 16 bytes, one at a time
PTR_ADDU a3, a2, a1
L(lst16l):
lb t0, 0(a1)
PTR_ADDIU a0, 1
PTR_ADDIU a1, 1
bne a1, a3, L(lst16l)
sb t0, -1(a0)
L(lst16e):
jr ra # Bye, bye
nop
L(shift):
PTR_SUBU a3, zero, a0 # Src and Dest unaligned
andi a3, 0x7 # (unoptimized case...)
beq a3, zero, L(shft1)
PTR_SUBU a2, a3 # a2 = bytes left
LDHI t0, 0(a1) # Take care of first odd part
LDLO t0, 7(a1)
PTR_ADDU a1, a3
SDHI t0, 0(a0)
PTR_ADDU a0, a3
L(shft1):
andi t0, a2, 0x7
PTR_SUBU a3, a2, t0
PTR_ADDU a3, a1
L(shfth):
LDHI t1, 0(a1) # Limp through, dword by dword
LDLO t1, 7(a1)
PTR_ADDIU a0, 8
PTR_ADDIU a1, 8
bne a1, a3, L(shfth)
sd t1, -8(a0)
b L(last16) # Handle anything which may be left
move a2, t0
.set reorder
END (memcpy)
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