118 lines
2.9 KiB
ArmAsm
118 lines
2.9 KiB
ArmAsm
/* Optimized strcpy implementation for PowerPC.
|
|
Copyright (C) 1997-2022 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <sysdep.h>
|
|
|
|
/* See strlen.s for comments on how the end-of-string testing works. */
|
|
|
|
/* char * [r3] strcpy (char *dest [r3], const char *src [r4]) */
|
|
|
|
EALIGN (strcpy, 4, 0)
|
|
|
|
#define rTMP r0
|
|
#define rRTN r3 /* incoming DEST arg preserved as result */
|
|
#define rSRC r4 /* pointer to previous word in src */
|
|
#define rDEST r5 /* pointer to previous word in dest */
|
|
#define rWORD r6 /* current word from src */
|
|
#define rFEFE r7 /* constant 0xfefefeff (-0x01010101) */
|
|
#define r7F7F r8 /* constant 0x7f7f7f7f */
|
|
#define rNEG r9 /* ~(word in s1 | 0x7f7f7f7f) */
|
|
#define rALT r10 /* alternate word from src */
|
|
|
|
|
|
or rTMP, rSRC, rRTN
|
|
clrlwi. rTMP, rTMP, 30
|
|
addi rDEST, rRTN, -4
|
|
bne L(unaligned)
|
|
|
|
lis rFEFE, -0x101
|
|
lis r7F7F, 0x7f7f
|
|
lwz rWORD, 0(rSRC)
|
|
addi rFEFE, rFEFE, -0x101
|
|
addi r7F7F, r7F7F, 0x7f7f
|
|
b L(g2)
|
|
|
|
L(g0): lwzu rALT, 4(rSRC)
|
|
stwu rWORD, 4(rDEST)
|
|
add rTMP, rFEFE, rALT
|
|
nor rNEG, r7F7F, rALT
|
|
and. rTMP, rTMP, rNEG
|
|
bne- L(g1)
|
|
lwzu rWORD, 4(rSRC)
|
|
stwu rALT, 4(rDEST)
|
|
L(g2): add rTMP, rFEFE, rWORD
|
|
nor rNEG, r7F7F, rWORD
|
|
and. rTMP, rTMP, rNEG
|
|
beq+ L(g0)
|
|
|
|
mr rALT, rWORD
|
|
/* We've hit the end of the string. Do the rest byte-by-byte. */
|
|
L(g1):
|
|
#ifdef __LITTLE_ENDIAN__
|
|
rlwinm. rTMP, rALT, 0, 24, 31
|
|
stb rALT, 4(rDEST)
|
|
beqlr-
|
|
rlwinm. rTMP, rALT, 24, 24, 31
|
|
stb rTMP, 5(rDEST)
|
|
beqlr-
|
|
rlwinm. rTMP, rALT, 16, 24, 31
|
|
stb rTMP, 6(rDEST)
|
|
beqlr-
|
|
rlwinm rTMP, rALT, 8, 24, 31
|
|
stb rTMP, 7(rDEST)
|
|
blr
|
|
#else
|
|
rlwinm. rTMP, rALT, 8, 24, 31
|
|
stb rTMP, 4(rDEST)
|
|
beqlr-
|
|
rlwinm. rTMP, rALT, 16, 24, 31
|
|
stb rTMP, 5(rDEST)
|
|
beqlr-
|
|
rlwinm. rTMP, rALT, 24, 24, 31
|
|
stb rTMP, 6(rDEST)
|
|
beqlr-
|
|
stb rALT, 7(rDEST)
|
|
blr
|
|
#endif
|
|
|
|
/* Oh well. In this case, we just do a byte-by-byte copy. */
|
|
.align 4
|
|
nop
|
|
L(unaligned):
|
|
lbz rWORD, 0(rSRC)
|
|
addi rDEST, rRTN, -1
|
|
cmpwi rWORD, 0
|
|
beq- L(u2)
|
|
|
|
L(u0): lbzu rALT, 1(rSRC)
|
|
stbu rWORD, 1(rDEST)
|
|
cmpwi rALT, 0
|
|
beq- L(u1)
|
|
nop /* Let 601 load start of loop. */
|
|
lbzu rWORD, 1(rSRC)
|
|
stbu rALT, 1(rDEST)
|
|
cmpwi rWORD, 0
|
|
bne+ L(u0)
|
|
L(u2): stb rWORD, 1(rDEST)
|
|
blr
|
|
L(u1): stb rALT, 1(rDEST)
|
|
blr
|
|
|
|
END (strcpy)
|
|
libc_hidden_builtin_def (strcpy)
|