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 000000000000..20b07b62b77c
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+++ b/arch/mn10300/lib/memmove.S
@@ -0,0 +1,160 @@
+/* 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