23 lines
479 B
C
23 lines
479 B
C
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#include "util.h"
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#include <limits.h>
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#ifndef __has_builtin
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#define __has_builtin(_) 0
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#endif
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unsigned long log2lu(unsigned long n) {
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#if __has_builtin(__builtin_clz)
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return sizeof(unsigned long) * CHAR_BIT - __builtin_clz(n) - 1;
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#else
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unsigned long res = 0;
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while(n >>= 1) ++res;
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return res;
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#endif
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}
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uint32_t rotl(uint32_t n, unsigned int c) {
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const unsigned int mask = (CHAR_BIT*sizeof(n) - 1);
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c &= mask;
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return (n<<c) | (n>>( (-c)&mask ));
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}
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