external/bsd/bind/dist/lib/isc/safe.c

   1 /*      $NetBSD: safe.c,v 1.3 2014/12/10 04:37:59 christos Exp $        */
   2
   3 /*
   4  * Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  11  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  12  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  13  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  14  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  15  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  16  * PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /* Id */
  20
  21 /*! \file */
  22
  23 #include <config.h>
  24
  25 #include <isc/safe.h>
  26 #include <isc/util.h>
  27
  28 #ifdef _MSC_VER
  29 #pragma optimize("", off)
  30 #endif
  31
  32 isc_boolean_t
  33 isc_safe_memcmp(const void *s1, const void *s2, size_t n) {
  34         isc_uint8_t acc = 0;
  35
  36         if (n != 0U) {
  37                 const isc_uint8_t *p1 = s1, *p2 = s2;
  38
  39                 do {
  40                         acc |= *p1++ ^ *p2++;
  41                 } while (--n != 0U);
  42         }
  43         return (ISC_TF(acc == 0));
  44 }