diff options
Diffstat (limited to 'libc/string/arm/memcmp.S')
-rw-r--r-- | libc/string/arm/memcmp.S | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/libc/string/arm/memcmp.S b/libc/string/arm/memcmp.S new file mode 100644 index 000000000..8f3f137b0 --- /dev/null +++ b/libc/string/arm/memcmp.S @@ -0,0 +1,53 @@ +/* + * Copyright (c) 2002 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. + * + * Adapted for uClibc from NetBSD memcmp.S, version 1.2 2003/04/05 + * by Erik Andersen <andersen@codepoet.org> + */ + + + .text + .global memcmp; + .type memcmp,%function + .align 4; \ + +memcmp: + /* if ((len - 1) < 0) return 0 */ + subs r2, r2, #1 + movmi r0, #0 + movmi pc, lr + + /* ip == last src address to compare */ + add ip, r0, r2 +1: + ldrb r2, [r0], #1 + ldrb r3, [r1], #1 + cmp ip, r0 + cmpcs r2, r3 + beq 1b + sub r0, r2, r3 + mov pc, lr |