1 files changed, 160 insertions, 0 deletions
diff --git a/arch/mn10300/lib/memmove.S b/arch/mn10300/lib/memmove.S
new file mode 100644
index 00000000000..20b07b62b77
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+++ b/arch/mn10300/lib/memmove.S
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+/* MN10300 Optimised simple memory to memory copy, with support for overlapping
+ * regions
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <asm/cache.h>
+
+        .section .text
+        .balign	L1_CACHE_BYTES
+
+###############################################################################
+#
+# void *memmove(void *dst, const void *src, size_t n)
+#
+###############################################################################
+	.globl	memmove
+        .type	memmove,@function
+memmove:
+	# fall back to memcpy if dst < src to work bottom up
+	cmp	d1,d0
+	bcs	memmove_memcpy
+
+	# work top down
+	movm	[d2,d3],(sp)
+	mov	d0,(12,sp)
+	mov	d1,(16,sp)
+	mov	(20,sp),d2			# count
+	add	d0,d2,a0			# dst end
+	add	d1,d2,a1			# src end
+	mov	d0,e3				# the return value
+
+	cmp	+0,d2
+	beq	memmove_done			# return if zero-length copy
+
+	# see if the three parameters are all four-byte aligned
+	or	d0,d1,d3
+	or	d2,d3
+	and	+3,d3
+	bne	memmove_1			# jump if not
+
+	# we want to transfer as much as we can in chunks of 32 bytes
+	add	-4,a1
+	cmp	+31,d2
+	bls	memmove_4_remainder		# 4-byte aligned remainder
+
+	add	-32,d2
+	mov	+32,d3
+
+memmove_4_loop:
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+	mov	(a1),d1
+	sub_sub	+4,a1,+4,a0
+	mov	d1,(a0)
+
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+	mov	(a1),d1
+	sub_sub	+4,a1,+4,a0
+	mov	d1,(a0)
+
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+	mov	(a1),d1
+	sub_sub	+4,a1,+4,a0
+	mov	d1,(a0)
+
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+	mov	(a1),d1
+	sub_sub	+4,a1,+4,a0
+	mov	d1,(a0)
+
+	sub	d3,d2
+	bcc	memmove_4_loop
+
+	add	d3,d2
+	beq	memmove_4_no_remainder
+
+memmove_4_remainder:
+	# cut 4-7 words down to 0-3
+	cmp	+16,d2
+	bcs	memmove_4_three_or_fewer_words
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+	mov	(a1),d1
+	sub_sub	+4,a1,+4,a0
+	mov	d1,(a0)
+	mov	(a1),e0
+	sub_sub	+4,a1,+4,a0
+	mov	e0,(a0)
+	mov	(a1),e1
+	sub_sub	+4,a1,+4,a0
+	mov	e1,(a0)
+	add	-16,d2
+	beq	memmove_4_no_remainder
+
+	# copy the remaining 1, 2 or 3 words
+memmove_4_three_or_fewer_words:
+	cmp	+8,d2
+	bcs	memmove_4_one_word
+	beq	memmove_4_two_words
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+memmove_4_two_words:
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+memmove_4_one_word:
+	mov	(a1),d0
+	sub_sub	+4,a1,+4,a0
+	mov	d0,(a0)
+
+memmove_4_no_remainder:
+	# check we copied the correct amount
+	# TODO: REMOVE CHECK
+	sub	e3,a0,d2
+	beq	memmove_done
+	break
+	break
+	break
+
+memmove_done:
+	mov	e3,a0
+	ret	[d2,d3],8
+
+	# handle misaligned copying
+memmove_1:
+	add	-1,a1
+	add	-1,d2
+	mov	+1,d3
+	setlb					# setlb requires the next insns
+						# to occupy exactly 4 bytes
+
+	sub	d3,d2
+	movbu	(a1),d0
+	sub_sub	d3,a1,d3,a0
+	movbu	d0,(a0)
+	lcc
+
+	mov	e3,a0
+	ret	[d2,d3],8
+
+memmove_memcpy:
+	jmp	memcpy
+
+memmove_end:
+	.size	memmove, memmove_end-memmove