glibc/sysdeps/powerpc/powerpc64/strcpy.S

217 lines
4.8 KiB
ArmAsm

/* Optimized strcpy implementation for PowerPC64.
Copyright (C) 1997-2015 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
<http://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]) */
#ifdef USE_AS_STPCPY
# define FUNC_NAME __stpcpy
#else
# define FUNC_NAME strcpy
#endif
EALIGN (FUNC_NAME, 4, 0)
CALL_MCOUNT 2
#define rTMP r0
#ifdef USE_AS_STPCPY
#define rRTN r3 /* pointer to previous word/doubleword in dest */
#else
#define rRTN r12 /* pointer to previous word/doubleword in dest */
#endif
#define rSRC r4 /* pointer to previous word/doubleword in src */
#define rWORD r6 /* current word from src */
#define rFEFE r7 /* constant 0xfefefeff | 0xfefefefefefefeff */
#define r7F7F r8 /* constant 0x7f7f7f7f | 0x7f7f7f7f7f7f7f7f */
#define rNEG r9 /* ~(word in s1 | r7F7F) */
#define rALT r10 /* alternate word from src */
#ifndef USE_AS_STPCPY
/* Save the dst pointer to use as return value. */
mr rRTN, r3
#endif
or rTMP, rSRC, rRTN
clrldi. rTMP, rTMP, 61
bne L(check_word_alignment)
/* For doubleword aligned memory, operate using doubleword load and stores. */
addi rRTN, rRTN, -8
lis rFEFE, -0x101
lis r7F7F, 0x7f7f
ld rWORD, 0(rSRC)
addi rFEFE, rFEFE, -0x101
addi r7F7F, r7F7F, 0x7f7f
sldi rTMP, rFEFE, 32
insrdi r7F7F, r7F7F, 32, 0
add rFEFE, rFEFE, rTMP
b L(g2)
L(g0): ldu rALT, 8(rSRC)
stdu rWORD, 8(rRTN)
add rTMP, rFEFE, rALT
nor rNEG, r7F7F, rALT
and. rTMP, rTMP, rNEG
bne- L(g1)
ldu rWORD, 8(rSRC)
stdu rALT, 8(rRTN)
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__
extrdi. rTMP, rALT, 8, 56
stbu rALT, 8(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 48
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 40
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 32
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 24
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 16
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 8
stbu rTMP, 1(rRTN)
beqlr-
extrdi rTMP, rALT, 8, 0
stbu rTMP, 1(rRTN)
#else
extrdi. rTMP, rALT, 8, 0
stbu rTMP, 8(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 8
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 16
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 24
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 32
stbu rTMP, 1(rRTN)
beqlr
extrdi. rTMP, rALT, 8, 40
stbu rTMP, 1(rRTN)
beqlr-
extrdi. rTMP, rALT, 8, 48
stbu rTMP, 1(rRTN)
beqlr-
stbu rALT, 1(rRTN)
#endif
blr
L(check_word_alignment):
clrldi. rTMP, rTMP, 62
bne L(unaligned)
/* For word aligned memory, operate using word load and stores. */
addi rRTN, rRTN, -4
lis rFEFE, -0x101
lis r7F7F, 0x7f7f
lwz rWORD, 0(rSRC)
addi rFEFE, rFEFE, -0x101
addi r7F7F, r7F7F, 0x7f7f
b L(g5)
L(g3): lwzu rALT, 4(rSRC)
stwu rWORD, 4(rRTN)
add rTMP, rFEFE, rALT
nor rNEG, r7F7F, rALT
and. rTMP, rTMP, rNEG
bne- L(g4)
lwzu rWORD, 4(rSRC)
stwu rALT, 4(rRTN)
L(g5): add rTMP, rFEFE, rWORD
nor rNEG, r7F7F, rWORD
and. rTMP, rTMP, rNEG
beq+ L(g3)
mr rALT, rWORD
/* We've hit the end of the string. Do the rest byte-by-byte. */
L(g4):
#ifdef __LITTLE_ENDIAN__
rlwinm. rTMP, rALT, 0, 24, 31
stbu rALT, 4(rRTN)
beqlr-
rlwinm. rTMP, rALT, 24, 24, 31
stbu rTMP, 1(rRTN)
beqlr-
rlwinm. rTMP, rALT, 16, 24, 31
stbu rTMP, 1(rRTN)
beqlr-
rlwinm rTMP, rALT, 8, 24, 31
stbu rTMP, 1(rRTN)
#else
rlwinm. rTMP, rALT, 8, 24, 31
stbu rTMP, 4(rRTN)
beqlr-
rlwinm. rTMP, rALT, 16, 24, 31
stbu rTMP, 1(rRTN)
beqlr-
rlwinm. rTMP, rALT, 24, 24, 31
stbu rTMP, 1(rRTN)
beqlr-
stbu rALT, 1(rRTN)
#endif
blr
/* Oh well. In this case, we just do a byte-by-byte copy. */
.align 4
nop
L(unaligned):
lbz rWORD, 0(rSRC)
addi rRTN, rRTN, -1
cmpwi rWORD, 0
beq- L(u2)
L(u0): lbzu rALT, 1(rSRC)
stbu rWORD, 1(rRTN)
cmpwi rALT, 0
beq- L(u1)
nop /* Let 601 load start of loop. */
lbzu rWORD, 1(rSRC)
stbu rALT, 1(rRTN)
cmpwi rWORD, 0
bne+ L(u0)
L(u2): stbu rWORD, 1(rRTN)
blr
L(u1): stbu rALT, 1(rRTN)
blr
END (FUNC_NAME)
#ifndef USE_AS_STPCPY
libc_hidden_builtin_def (strcpy)
#endif