diff options
Diffstat (limited to 'arch/sh/lib/memcpy.S')
| -rw-r--r-- | arch/sh/lib/memcpy.S | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/arch/sh/lib/memcpy.S b/arch/sh/lib/memcpy.S new file mode 100644 index 000000000000..232fab34c261 --- /dev/null +++ b/arch/sh/lib/memcpy.S @@ -0,0 +1,227 @@ +/* $Id: memcpy.S,v 1.3 2001/07/27 11:50:52 gniibe Exp $ + * + * "memcpy" implementation of SuperH + * + * Copyright (C) 1999 Niibe Yutaka + * + */ + +/* + * void *memcpy(void *dst, const void *src, size_t n); + * No overlap between the memory of DST and of SRC are assumed. + */ + +#include <linux/linkage.h> +ENTRY(memcpy) + tst r6,r6 + bt/s 9f ! if n=0, do nothing + mov r4,r0 + sub r4,r5 ! From here, r5 has the distance to r0 + add r6,r0 ! From here, r0 points the end of copying point + mov #12,r1 + cmp/gt r6,r1 + bt/s 7f ! if it's too small, copy a byte at once + add #-1,r5 + add #1,r5 + ! From here, r6 is free + ! + ! r4 --> [ ... ] DST [ ... ] SRC + ! [ ... ] [ ... ] + ! : : + ! r0 --> [ ... ] r0+r5 --> [ ... ] + ! + ! + mov r5,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 +7: mov r4,r2 + add #1,r2 +8: + cmp/hi r2,r0 + mov.b @(r0,r5),r1 + bt/s 8b ! while (r0>r2) + mov.b r1,@-r0 +9: + rts + nop + +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 #-4,r5 + add #3,r5 +1: dt r3 + mov.b @(r0,r5),r1 + bf/s 1b + mov.b r1,@-r0 + ! + add #-3,r5 +2: ! Second, copy a long word at once + mov r4,r2 + add #7,r2 +3: mov.l @(r0,r5),r1 + cmp/hi r2,r0 + bt/s 3b + mov.l r1,@-r0 + ! + ! Third, copy a byte at once, if necessary + cmp/eq r4,r0 + bt/s 9b + add #3,r5 + bra 8b + add #-6,r2 + +case1: + ! + ! 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,r5 +1: dt r3 + mov.b @(r0,r5),r1 + bf/s 1b + mov.b r1,@-r0 + ! +2: ! Second, read a long word and write a long word at once + mov.l @(r0,r5),r1 + add #-4,r5 + mov r4,r2 + add #7,r2 + ! +#ifdef __LITTLE_ENDIAN__ +3: mov r1,r3 ! RQPO + shll16 r3 + shll8 r3 ! Oxxx + mov.l @(r0,r5),r1 ! NMLK + mov r1,r6 + shlr8 r6 ! xNML + or r6,r3 ! ONML + cmp/hi r2,r0 + bt/s 3b + mov.l r3,@-r0 +#else +3: mov r1,r3 ! OPQR + shlr16 r3 + shlr8 r3 ! xxxO + mov.l @(r0,r5),r1 ! KLMN + mov r1,r6 + shll8 r6 ! LMNx + or r6,r3 ! LMNO + cmp/hi r2,r0 + bt/s 3b + mov.l r3,@-r0 +#endif + ! + ! Third, copy a byte at once, if necessary + cmp/eq r4,r0 + bt/s 9b + add #4,r5 + bra 8b + add #-6,r2 + +case2: + ! + ! GHIJ KLMN OPQR --> ..GH IJKL MNOP QR.. + ! + ! First, align to word boundary + tst #1,r0 + bt/s 2f + add #-1,r5 + mov.b @(r0,r5),r1 + mov.b r1,@-r0 + ! +2: ! Second, read a word and write a word at once + add #-1,r5 + mov r4,r2 + add #3,r2 + ! +3: mov.w @(r0,r5),r1 + cmp/hi r2,r0 + bt/s 3b + mov.w r1,@-r0 + ! + ! Third, copy a byte at once, if necessary + cmp/eq r4,r0 + bt/s 9b + add #1,r5 + mov.b @(r0,r5),r1 + rts + mov.b r1,@-r0 + +case3: + ! + ! 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,r5 +1: dt r3 + mov.b @(r0,r5),r1 + bf/s 1b + mov.b r1,@-r0 + ! +2: ! Second, read a long word and write a long word at once + add #-2,r5 + mov.l @(r0,r5),r1 + add #-4,r5 + mov r4,r2 + add #7,r2 + ! +#ifdef __LITTLE_ENDIAN__ +3: mov r1,r3 ! RQPO + shll8 r3 ! QPOx + mov.l @(r0,r5),r1 ! NMLK + mov r1,r6 + shlr16 r6 + shlr8 r6 ! xxxN + or r6,r3 ! QPON + cmp/hi r2,r0 + bt/s 3b + mov.l r3,@-r0 +#else +3: mov r1,r3 ! OPQR + shlr8 r3 ! xOPQ + mov.l @(r0,r5),r1 ! KLMN + mov r1,r6 + shll16 r6 + shll8 r6 ! Nxxx + or r6,r3 ! NOPQ + cmp/hi r2,r0 + bt/s 3b + mov.l r3,@-r0 +#endif + ! + ! Third, copy a byte at once, if necessary + cmp/eq r4,r0 + bt/s 9b + add #6,r5 + bra 8b + add #-6,r2 |