xref: /aosp_15_r20/external/llvm-libc/src/string/memmove.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Implementation of memmove -----------------------------------------===//
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/string/memmove.h"
10 #include "src/__support/macros/config.h"
11 #include "src/string/memory_utils/inline_memcpy.h"
12 #include "src/string/memory_utils/inline_memmove.h"
13 #include <stddef.h> // size_t
14 
15 namespace LIBC_NAMESPACE_DECL {
16 
17 LLVM_LIBC_FUNCTION(void *, memmove,
18                    (void *dst, const void *src, size_t count)) {
19   // Memmove may handle some small sizes as efficiently as inline_memcpy.
20   // For these sizes we may not do is_disjoint check.
21   // This both avoids additional code for the most frequent smaller sizes
22   // and removes code bloat (we don't need the memcpy logic for small sizes).
23   if (inline_memmove_small_size(dst, src, count))
24     return dst;
25   if (is_disjoint(dst, src, count))
26     inline_memcpy(dst, src, count);
27   else
28     inline_memmove_follow_up(dst, src, count);
29   return dst;
30 }
31 
32 } // namespace LIBC_NAMESPACE_DECL
33