linux/arch/arc/lib/strcpy-700.S
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

68 lines
1.4 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*/
/* If dst and src are 4 byte aligned, copy 8 bytes at a time.
If the src is 4, but not 8 byte aligned, we first read 4 bytes to get
it 8 byte aligned. Thus, we can do a little read-ahead, without
dereferencing a cache line that we should not touch.
Note that short and long instructions have been scheduled to avoid
branch stalls.
The beq_s to r3z could be made unaligned & long to avoid a stall
there, but the it is not likely to be taken often, and it
would also be likey to cost an unaligned mispredict at the next call. */
#include <linux/linkage.h>
ENTRY_CFI(strcpy)
or r2,r0,r1
bmsk_s r2,r2,1
brne.d r2,0,charloop
mov_s r10,r0
ld_s r3,[r1,0]
mov r8,0x01010101
bbit0.d r1,2,loop_start
ror r12,r8
sub r2,r3,r8
bic_s r2,r2,r3
tst_s r2,r12
bne r3z
mov_s r4,r3
.balign 4
loop:
ld.a r3,[r1,4]
st.ab r4,[r10,4]
loop_start:
ld.a r4,[r1,4]
sub r2,r3,r8
bic_s r2,r2,r3
tst_s r2,r12
bne_s r3z
st.ab r3,[r10,4]
sub r2,r4,r8
bic r2,r2,r4
tst r2,r12
beq loop
mov_s r3,r4
#ifdef __LITTLE_ENDIAN__
r3z: bmsk.f r1,r3,7
lsr_s r3,r3,8
#else
r3z: lsr.f r1,r3,24
asl_s r3,r3,8
#endif
bne.d r3z
stb.ab r1,[r10,1]
j_s [blink]
.balign 4
charloop:
ldb.ab r3,[r1,1]
brne.d r3,0,charloop
stb.ab r3,[r10,1]
j [blink]
END_CFI(strcpy)