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/*
* Copyright 2017 Google
*
* 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 "Firestore/core/src/firebase/firestore/util/bits.h"
#include "Firestore/core/src/firebase/firestore/util/hard_assert.h"
namespace firebase {
namespace firestore {
namespace util {
int Bits::Log2Floor_Portable(uint32_t n) {
if (n == 0) return -1;
int log = 0;
uint32_t value = n;
for (int i = 4; i >= 0; --i) {
int shift = (1 << i);
uint32_t x = value >> shift;
if (x != 0) {
value = x;
log += shift;
}
}
HARD_ASSERT(value == 1);
return log;
}
} // namespace util
} // namespace firestore
} // namespace firebase
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