1956385a7d
Provide a way to only customize specific string operations, such as for memcpy with the DMA capability by ROM. Signed-off-by: yangdongdong <yangdongdong@xiaomi.com>
61 lines
1.9 KiB
C
61 lines
1.9 KiB
C
/****************************************************************************
|
|
* libs/libc/string/lib_memcmp.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
#include <sys/types.h>
|
|
#include <string.h>
|
|
|
|
#include "libc.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
#if !defined(CONFIG_LIBC_ARCH_MEMCMP) && defined(LIBC_BUILD_MEMCMP)
|
|
#undef memcmp /* See mm/README.txt */
|
|
no_builtin("memcmp")
|
|
int memcmp(FAR const void *s1, FAR const void *s2, size_t n)
|
|
{
|
|
FAR unsigned char *p1 = (FAR unsigned char *)s1;
|
|
FAR unsigned char *p2 = (FAR unsigned char *)s2;
|
|
|
|
while (n-- > 0)
|
|
{
|
|
if (*p1 < *p2)
|
|
{
|
|
return -1;
|
|
}
|
|
else if (*p1 > *p2)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
p1++;
|
|
p2++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|