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			137 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			137 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, write to the Free
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|    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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|    02111-1307 USA.  */
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| 
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| #include <sysdep.h>
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| #include <endian.h>
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| 
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| 
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| /* void *memcpy(void *s1, const void *s2, size_t n);  */
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| 
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| #if __BYTE_ORDER == __BIG_ENDIAN
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| #  define LWHI	lwl		/* high part is left in big-endian	*/
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| #  define SWHI	swl		/* high part is left in big-endian	*/
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| #  define LWLO	lwr		/* low part is right in big-endian	*/
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| #  define SWLO	swr		/* low part is right in big-endian	*/
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| #else
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| #  define LWHI	lwr		/* high part is right in little-endian	*/
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| #  define SWHI	swr		/* high part is right in little-endian	*/
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| #  define LWLO	lwl		/* low part is left in little-endian	*/
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| #  define SWLO	swl		/* low part is left in little-endian	*/
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| #endif
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| 
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| ENTRY (memcpy)
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| 	.set	noreorder
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| 
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| 	slti	t0, a2, 8		# Less than 8?
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| 	bne	t0, zero, L(last8)
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| 	move	v0, a0			# Setup exit value before too late
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| 
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| 	xor	t0, a1, a0		# Find a0/a1 displacement
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| 	andi	t0, 0x3
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| 	bne	t0, zero, L(shift)	# Go handle the unaligned case
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| 	subu	t1, zero, a1
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| 	andi	t1, 0x3			# a0/a1 are aligned, but are we
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| 	beq	t1, zero, L(chk8w)	#  starting in the middle of a word?
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| 	subu	a2, t1
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| 	LWHI	t0, 0(a1)		# Yes we are... take care of that
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| 	addu	a1, t1
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| 	SWHI	t0, 0(a0)
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| 	addu	a0, t1
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| 
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| L(chk8w):	
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| 	andi	t0, a2, 0x1f		# 32 or more bytes left?
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| 	beq	t0, a2, L(chk1w)
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| 	subu	a3, a2, t0		# Yes
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| 	addu	a3, a1			# a3 = end address of loop
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| 	move	a2, t0			# a2 = what will be left after loop
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| L(lop8w):	
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| 	lw	t0,  0(a1)		# Loop taking 8 words at a time
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| 	lw	t1,  4(a1)
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| 	lw	t2,  8(a1)
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| 	lw	t3, 12(a1)
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| 	lw	t4, 16(a1)
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| 	lw	t5, 20(a1)
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| 	lw	t6, 24(a1)
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| 	lw	t7, 28(a1)
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| 	addiu	a0, 32
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| 	addiu	a1, 32
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| 	sw	t0, -32(a0)
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| 	sw	t1, -28(a0)
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| 	sw	t2, -24(a0)
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| 	sw	t3, -20(a0)
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| 	sw	t4, -16(a0)
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| 	sw	t5, -12(a0)
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| 	sw	t6,  -8(a0)
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| 	bne	a1, a3, L(lop8w)
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| 	sw	t7,  -4(a0)
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| 
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| L(chk1w):	
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| 	andi	t0, a2, 0x3		# 4 or more bytes left?
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| 	beq	t0, a2, L(last8)
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| 	subu	a3, a2, t0		# Yes, handle them one word at a time
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| 	addu	a3, a1			# a3 again end address
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| 	move	a2, t0
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| L(lop1w):	
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| 	lw	t0, 0(a1)
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| 	addiu	a0, 4
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| 	addiu	a1, 4
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| 	bne	a1, a3, L(lop1w)
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| 	sw	t0, -4(a0)
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| 
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| L(last8):	
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| 	blez	a2, L(lst8e)		# Handle last 8 bytes, one at a time
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| 	addu	a3, a2, a1
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| L(lst8l):	
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| 	lb	t0, 0(a1)
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| 	addiu	a0, 1
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| 	addiu	a1, 1
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| 	bne	a1, a3, L(lst8l)
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| 	sb	t0, -1(a0)
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| L(lst8e):	
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| 	jr	ra			# Bye, bye
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| 	nop
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| 
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| L(shift):	
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| 	subu	a3, zero, a0		# Src and Dest unaligned 
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| 	andi	a3, 0x3			#  (unoptimized case...)
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| 	beq	a3, zero, L(shft1)
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| 	subu	a2, a3			# a2 = bytes left
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| 	LWHI	t0, 0(a1)		# Take care of first odd part
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| 	LWLO	t0, 3(a1)
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| 	addu	a1, a3
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| 	SWHI	t0, 0(a0)
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| 	addu	a0, a3
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| L(shft1):	
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| 	andi	t0, a2, 0x3
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| 	subu	a3, a2, t0
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| 	addu	a3, a1
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| L(shfth):	
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| 	LWHI	t1, 0(a1)		# Limp through, word by word
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| 	LWLO	t1, 3(a1)
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| 	addiu	a0, 4
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| 	addiu	a1, 4
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| 	bne	a1, a3, L(shfth)
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| 	sw	t1, -4(a0)
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| 	b	L(last8)		# Handle anything which may be left
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| 	move	a2, t0
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| 
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| 	.set	reorder
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| END (memcpy)
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| libc_hidden_builtin_def (memcpy)
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