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/*
* 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
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