newlib-cygwin/newlib/libc/machine/arm/strcmp-armv4t.S

54 lines
2.0 KiB
ArmAsm

/*
* Copyright (c) 2012-2014 ARM Ltd
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* This version is only used when we want a very basic Thumb1
implementation or for size, otherwise we use the base ARMv4
version. This is also suitable for ARMv6-M. */
.thumb
.syntax unified
.arch armv4t
.eabi_attribute Tag_also_compatible_with, "\006\013" /* ARMv6-M. */
.eabi_attribute Tag_ARM_ISA_use, 0
def_fn strcmp
.cfi_startproc
1:
ldrb r2, [r0]
ldrb r3, [r1]
cmp r2, #0
beq 2f
adds r0, r0, #1
adds r1, r1, #1
cmp r2, r3
beq 1b
2:
subs r0, r2, r3
bx lr
.cfi_endproc
.size strcmp, . - strcmp