blob: 486e3b0e359701587d6781337f4fbc2576c567ad [file] [log] [blame]
// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC. All rights reserved.
// https://developers.google.com/protocol-buffers/
///
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#ifndef UPB_BASE_INTERNAL_LOG2_H_
#define UPB_BASE_INTERNAL_LOG2_H_
// Must be last.
#include "upb/port/def.inc"
#ifdef __cplusplus
extern "C" {
#endif
UPB_INLINE int upb_Log2Ceiling(int x) {
if (x <= 1) return 0;
#ifdef __GNUC__
return 32 - __builtin_clz(x - 1);
#else
int lg2 = 0;
while ((1 << lg2) < x) lg2++;
return lg2;
#endif
}
UPB_INLINE int upb_Log2CeilingSize(int x) { return 1 << upb_Log2Ceiling(x); }
#ifdef __cplusplus
} /* extern "C" */
#endif
#include "upb/port/undef.inc"
#endif /* UPB_BASE_INTERNAL_LOG2_H_ */