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/* ===-- clzdi2.c - Implement __clzdi2 -------------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is distributed under the University of Illinois Open Source
* License. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __clzdi2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: the number of leading 0-bits */
/* Precondition: a != 0 */
si_int
__clzdi2(di_int a)
{
dwords x;
x.all = a;
const si_int f = -(x.s.high == 0);
return __builtin_clz((x.s.high & ~f) | (x.s.low & f)) +
(f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
}
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