xref: /aosp_15_r20/external/llvm-libc/src/string/memory_utils/inline_strcmp.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- str{,case}cmp implementation ----------------------------*- C++ -*-===//
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 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRCMP_H
10 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRCMP_H
11 
12 #include "src/__support/macros/config.h"
13 #include <stddef.h>
14 
15 namespace LIBC_NAMESPACE_DECL {
16 
17 template <typename Comp>
inline_strcmp(const char * left,const char * right,Comp && comp)18 LIBC_INLINE constexpr int inline_strcmp(const char *left, const char *right,
19                                         Comp &&comp) {
20   // TODO: Look at benefits for comparing words at a time.
21   for (; *left && !comp(*left, *right); ++left, ++right)
22     ;
23   return comp(*reinterpret_cast<const unsigned char *>(left),
24               *reinterpret_cast<const unsigned char *>(right));
25 }
26 
27 template <typename Comp>
inline_strncmp(const char * left,const char * right,size_t n,Comp && comp)28 LIBC_INLINE constexpr int inline_strncmp(const char *left, const char *right,
29                                          size_t n, Comp &&comp) {
30   if (n == 0)
31     return 0;
32 
33   // TODO: Look at benefits for comparing words at a time.
34   for (; n > 1; --n, ++left, ++right) {
35     char lc = *left;
36     if (!comp(lc, '\0') || comp(lc, *right))
37       break;
38   }
39   return comp(*reinterpret_cast<const unsigned char *>(left),
40               *reinterpret_cast<const unsigned char *>(right));
41 }
42 
43 } // namespace LIBC_NAMESPACE_DECL
44 
45 #endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRCMP_H
46