| /* | |
| * Copyright (C) 2007 The Android Open Source Project | |
| * | |
| * Licensed under the Apache License, Version 2.0 (the "License"); | |
| * you may not use this file except in compliance with the License. | |
| * You may obtain a copy of the License at | |
| * | |
| * http://www.apache.org/licenses/LICENSE-2.0 | |
| * | |
| * Unless required by applicable law or agreed to in writing, software | |
| * distributed under the License is distributed on an "AS IS" BASIS, | |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| * See the License for the specific language governing permissions and | |
| * limitations under the License. | |
| */ | |
| #include "clz.h" | |
| namespace android { | |
| int clz_impl(int32_t x) | |
| { | |
| #if defined(__arm__) && !defined(__thumb__) | |
| return __builtin_clz(x); | |
| #else | |
| if (!x) return 32; | |
| int e = 31; | |
| if (x&0xFFFF0000) { e -=16; x >>=16; } | |
| if (x&0x0000FF00) { e -= 8; x >>= 8; } | |
| if (x&0x000000F0) { e -= 4; x >>= 4; } | |
| if (x&0x0000000C) { e -= 2; x >>= 2; } | |
| if (x&0x00000002) { e -= 1; } | |
| return e; | |
| #endif | |
| } | |
| }; // namespace android |