xref: /aosp_15_r20/external/llvm-libc/src/unistd/swab.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1*71db0c75SAndroid Build Coastguard Worker //===-- Implementation of swab --------------------------------------------===//
2*71db0c75SAndroid Build Coastguard Worker //
3*71db0c75SAndroid Build Coastguard Worker // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*71db0c75SAndroid Build Coastguard Worker // See https://llvm.org/LICENSE.txt for license information.
5*71db0c75SAndroid Build Coastguard Worker // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*71db0c75SAndroid Build Coastguard Worker //
7*71db0c75SAndroid Build Coastguard Worker //===----------------------------------------------------------------------===//
8*71db0c75SAndroid Build Coastguard Worker 
9*71db0c75SAndroid Build Coastguard Worker #include "src/unistd/swab.h"
10*71db0c75SAndroid Build Coastguard Worker 
11*71db0c75SAndroid Build Coastguard Worker #include "src/__support/common.h"
12*71db0c75SAndroid Build Coastguard Worker #include "src/__support/macros/config.h"
13*71db0c75SAndroid Build Coastguard Worker 
14*71db0c75SAndroid Build Coastguard Worker namespace LIBC_NAMESPACE_DECL {
15*71db0c75SAndroid Build Coastguard Worker 
16*71db0c75SAndroid Build Coastguard Worker LLVM_LIBC_FUNCTION(void, swab,
17*71db0c75SAndroid Build Coastguard Worker                    (const void *__restrict from, void *__restrict to,
18*71db0c75SAndroid Build Coastguard Worker                     ssize_t n)) {
19*71db0c75SAndroid Build Coastguard Worker   const unsigned char *f = static_cast<const unsigned char *>(from);
20*71db0c75SAndroid Build Coastguard Worker   unsigned char *t = static_cast<unsigned char *>(to);
21*71db0c75SAndroid Build Coastguard Worker   for (ssize_t i = 1; i < n; i += 2) {
22*71db0c75SAndroid Build Coastguard Worker     t[i - 1] = f[i];
23*71db0c75SAndroid Build Coastguard Worker     t[i] = f[i - 1];
24*71db0c75SAndroid Build Coastguard Worker   }
25*71db0c75SAndroid Build Coastguard Worker }
26*71db0c75SAndroid Build Coastguard Worker 
27*71db0c75SAndroid Build Coastguard Worker } // namespace LIBC_NAMESPACE_DECL
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