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/* Copyright (c) 2001-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
/*
* We could use bits_required64() unconditionally, but that's unnecessary
* and way more heavy weight on 32-bit systems.
*/
#ifdef _LP64
#define BITS_REQUIRED(x) bits_required64(x)
#else
#define BITS_REQUIRED(x) bits_required32(x)
#endif
size_t nearest_power(size_t num)
{
i_assert(num <= ((size_t)1 << (CHAR_BIT*sizeof(size_t) - 1)));
if (num == 0)
return 1;
return 1UL << BITS_REQUIRED(num - 1);
}
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
/* Lucky you, it's all inline intrinsics */
#else
unsigned int bits_required8(uint8_t num)
{
int ret = 0;
if (num > 0xf) { ret += 4; num >>= 4; }
if (num > 0x3) { ret += 2; num >>= 2; }
num &= ~(num>>1); /* 3->2, else unchanged */
return ret + num;
}
#endif
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