memcmp16.h revision 907194a395ffa5bc27cad81adbed241f9fd772f0 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_RUNTIME_ARCH_MEMCMP16_H_
18#define ART_RUNTIME_ARCH_MEMCMP16_H_
19
20#include <cstddef>
21#include <cstdint>
22
23// memcmp16 support.
24//
25// This can either be optimized assembly code, in which case we expect a function __memcmp16,
26// or generic C support.
27//
28// In case of the generic support we declare two versions: one in this header file meant to be
29// inlined, and a static version that assembly stubs can link against.
30//
31// In both cases, MemCmp16 is declared.
32
33#if defined(__aarch64__) || defined(__arm__) || defined(__mips) || defined(__i386__)
34
35extern "C" uint32_t __memcmp16(const uint16_t* s0, const uint16_t* s1, size_t count);
36#define MemCmp16 __memcmp16
37
38#else
39
40// This is the generic inlined version.
41static inline int32_t MemCmp16(const uint16_t* s0, const uint16_t* s1, size_t count) {
42  for (size_t i = 0; i < count; i++) {
43    if (s0[i] != s1[i]) {
44      return static_cast<int32_t>(s0[i]) - static_cast<int32_t>(s1[i]);
45    }
46  }
47  return 0;
48}
49
50extern "C" int32_t memcmp16_generic_static(const uint16_t* s0, const uint16_t* s1, size_t count);
51#endif
52
53#endif  // ART_RUNTIME_ARCH_MEMCMP16_H_
54