summaryrefslogtreecommitdiffstats
path: root/arch/sh/lib/memmove.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/lib/memmove.S')
-rw-r--r--arch/sh/lib/memmove.S254
1 files changed, 254 insertions, 0 deletions
diff --git a/arch/sh/lib/memmove.S b/arch/sh/lib/memmove.S
new file mode 100644
index 00000000000..5a2211f0920
--- /dev/null
+++ b/arch/sh/lib/memmove.S
@@ -0,0 +1,254 @@
+/* $Id: memmove.S,v 1.2 2001/07/27 11:51:09 gniibe Exp $
+ *
+ * "memmove" implementation of SuperH
+ *
+ * Copyright (C) 1999 Niibe Yutaka
+ *
+ */
+
+/*
+ * void *memmove(void *dst, const void *src, size_t n);
+ * The memory areas may overlap.
+ */
+
+#include <linux/linkage.h>
+ENTRY(memmove)
+ ! if dest > src, call memcpy (it copies in decreasing order)
+ cmp/hi r5,r4
+ bf 1f
+ mov.l 2f,r0
+ jmp @r0
+ nop
+ .balign 4
+2: .long memcpy
+1:
+ sub r5,r4 ! From here, r4 has the distance to r0
+ tst r6,r6
+ bt/s 9f ! if n=0, do nothing
+ mov r5,r0
+ add r6,r5
+ mov #12,r1
+ cmp/gt r6,r1
+ bt/s 8f ! if it's too small, copy a byte at once
+ add #-1,r4
+ add #1,r4
+ !
+ ! [ ... ] DST [ ... ] SRC
+ ! [ ... ] [ ... ]
+ ! : :
+ ! r0+r4--> [ ... ] r0 --> [ ... ]
+ ! : :
+ ! [ ... ] [ ... ]
+ ! r5 -->
+ !
+ mov r4,r1
+ mov #3,r2
+ and r2,r1
+ shll2 r1
+ mov r0,r3 ! Save the value on R0 to R3
+ mova jmptable,r0
+ add r1,r0
+ mov.l @r0,r1
+ jmp @r1
+ mov r3,r0 ! and back to R0
+ .balign 4
+jmptable:
+ .long case0
+ .long case1
+ .long case2
+ .long case3
+
+ ! copy a byte at once
+8: mov.b @r0+,r1
+ cmp/hs r5,r0
+ bf/s 8b ! while (r0<r5)
+ mov.b r1,@(r0,r4)
+ add #1,r4
+9:
+ add r4,r0
+ rts
+ sub r6,r0
+
+case_none:
+ bra 8b
+ add #-1,r4
+
+case0:
+ !
+ ! GHIJ KLMN OPQR --> GHIJ KLMN OPQR
+ !
+ ! First, align to long word boundary
+ mov r0,r3
+ and r2,r3
+ tst r3,r3
+ bt/s 2f
+ add #-1,r4
+ mov #4,r2
+ sub r3,r2
+1: dt r2
+ mov.b @r0+,r1
+ bf/s 1b
+ mov.b r1,@(r0,r4)
+ !
+2: ! Second, copy a long word at once
+ add #-3,r4
+ add #-3,r5
+3: mov.l @r0+,r1
+ cmp/hs r5,r0
+ bf/s 3b
+ mov.l r1,@(r0,r4)
+ add #3,r5
+ !
+ ! Third, copy a byte at once, if necessary
+ cmp/eq r5,r0
+ bt/s 9b
+ add #4,r4
+ bra 8b
+ add #-1,r4
+
+case3:
+ !
+ ! GHIJ KLMN OPQR --> ...G HIJK LMNO PQR.
+ !
+ ! First, align to long word boundary
+ mov r0,r3
+ and r2,r3
+ tst r3,r3
+ bt/s 2f
+ add #-1,r4
+ mov #4,r2
+ sub r3,r2
+1: dt r2
+ mov.b @r0+,r1
+ bf/s 1b
+ mov.b r1,@(r0,r4)
+ !
+2: ! Second, read a long word and write a long word at once
+ add #-2,r4
+ mov.l @(r0,r4),r1
+ add #-7,r5
+ add #-4,r4
+ !
+#ifdef __LITTLE_ENDIAN__
+ shll8 r1
+3: mov r1,r3 ! JIHG
+ shlr8 r3 ! xJIH
+ mov.l @r0+,r1 ! NMLK
+ mov r1,r2
+ shll16 r2
+ shll8 r2 ! Kxxx
+ or r2,r3 ! KJIH
+ cmp/hs r5,r0
+ bf/s 3b
+ mov.l r3,@(r0,r4)
+#else
+ shlr8 r1
+3: mov r1,r3 ! GHIJ
+ shll8 r3 ! HIJx
+ mov.l @r0+,r1 ! KLMN
+ mov r1,r2
+ shlr16 r2
+ shlr8 r2 ! xxxK
+ or r2,r3 ! HIJK
+ cmp/hs r5,r0
+ bf/s 3b
+ mov.l r3,@(r0,r4)
+#endif
+ add #7,r5
+ !
+ ! Third, copy a byte at once, if necessary
+ cmp/eq r5,r0
+ bt/s 9b
+ add #7,r4
+ add #-3,r0
+ bra 8b
+ add #-1,r4
+
+case2:
+ !
+ ! GHIJ KLMN OPQR --> ..GH IJKL MNOP QR..
+ !
+ ! First, align to word boundary
+ tst #1,r0
+ bt/s 2f
+ add #-1,r4
+ mov.b @r0+,r1
+ mov.b r1,@(r0,r4)
+ !
+2: ! Second, read a word and write a word at once
+ add #-1,r4
+ add #-1,r5
+ !
+3: mov.w @r0+,r1
+ cmp/hs r5,r0
+ bf/s 3b
+ mov.w r1,@(r0,r4)
+ add #1,r5
+ !
+ ! Third, copy a byte at once, if necessary
+ cmp/eq r5,r0
+ bt/s 9b
+ add #2,r4
+ mov.b @r0,r1
+ mov.b r1,@(r0,r4)
+ bra 9b
+ add #1,r0
+
+case1:
+ !
+ ! GHIJ KLMN OPQR --> .GHI JKLM NOPQ R...
+ !
+ ! First, align to long word boundary
+ mov r0,r3
+ and r2,r3
+ tst r3,r3
+ bt/s 2f
+ add #-1,r4
+ mov #4,r2
+ sub r3,r2
+1: dt r2
+ mov.b @r0+,r1
+ bf/s 1b
+ mov.b r1,@(r0,r4)
+ !
+2: ! Second, read a long word and write a long word at once
+ mov.l @(r0,r4),r1
+ add #-7,r5
+ add #-4,r4
+ !
+#ifdef __LITTLE_ENDIAN__
+ shll16 r1
+ shll8 r1
+3: mov r1,r3 ! JIHG
+ shlr16 r3
+ shlr8 r3 ! xxxJ
+ mov.l @r0+,r1 ! NMLK
+ mov r1,r2
+ shll8 r2 ! MLKx
+ or r2,r3 ! MLKJ
+ cmp/hs r5,r0
+ bf/s 3b
+ mov.l r3,@(r0,r4)
+#else
+ shlr16 r1
+ shlr8 r1
+3: mov r1,r3 ! GHIJ
+ shll16 r3
+ shll8 r3 ! Jxxx
+ mov.l @r0+,r1 ! KLMN
+ mov r1,r2
+ shlr8 r2 ! xKLM
+ or r2,r3 ! JKLM
+ cmp/hs r5,r0
+ bf/s 3b ! while(r0<r5)
+ mov.l r3,@(r0,r4)
+#endif
+ add #7,r5
+ !
+ ! Third, copy a byte at once, if necessary
+ cmp/eq r5,r0
+ bt/s 9b
+ add #5,r4
+ add #-3,r0
+ bra 8b
+ add #-1,r4