libc/src/unistd/swab.cpp

   1 //===-- Implementation of swab --------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/unistd/swab.h"
  10
  11 #include "src/__support/common.h"
  12 #include "src/__support/macros/config.h"
  13
  14 namespace LIBC_NAMESPACE_DECL {
  15
  16 LLVM_LIBC_FUNCTION(void, swab,
  17                    (const void *__restrict from, void *__restrict to,
  18                     ssize_t n)) {
  19   const unsigned char *f = static_cast<const unsigned char *>(from);
  20   unsigned char *t = static_cast<unsigned char *>(to);
  21   for (ssize_t i = 1; i < n; i += 2) {
  22     t[i - 1] = f[i];
  23     t[i] = f[i - 1];
  24   }
  25 }
  26
  27 } // namespace LIBC_NAMESPACE_DECL