src/system/libroot/posix/string/strcmp.c

   1 /*
   2  * Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
   3  * Distributed under the terms of the MIT license.
   4  */
   5
   6
   7 #include <stdbool.h>
   8 #include <string.h>
   9 #include <SupportDefs.h>
  10
  11
  12 #define LACKS_ZERO_BYTE(value) \
  13         (((value - 0x01010101) & ~value & 0x80808080) == 0)
  14
  15 int
  16 strcmp(char const *a, char const *b)
  17 {
  18         while (true) {
  19                 int cmp = (unsigned char)*a - (unsigned char)*b++;
  20                 if (cmp != 0 || *a++ == '\0')
  21                         return cmp;
  22         }
  23 }