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/*
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* Copyright (c) 2009-2021, Google LLC
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of Google LLC nor the
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* names of its contributors may be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef UPB_BASE_LOG2_H_
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#define UPB_BASE_LOG2_H_
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// Must be last.
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#include "upb/port/def.inc"
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#ifdef __cplusplus
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extern "C" {
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#endif
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UPB_INLINE int upb_Log2Ceiling(int x) {
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if (x <= 1) return 0;
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#ifdef __GNUC__
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return 32 - __builtin_clz(x - 1);
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#else
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int lg2 = 0;
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while ((1 << lg2) < x) lg2++;
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return lg2;
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#endif
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}
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UPB_INLINE int upb_Log2CeilingSize(int x) { return 1 << upb_Log2Ceiling(x); }
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#ifdef __cplusplus
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} /* extern "C" */
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#endif
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#include "upb/port/undef.inc"
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#endif /* UPB_BASE_LOG2_H_ */
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