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/* ===-- ffsdi2.c - Implement __ffsdi2 -------------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __ffsdi2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: the index of the least significant 1-bit in a, or
* the value zero if a is zero. The least significant bit is index one.
*/
COMPILER_RT_ABI si_int
__ffsdi2(di_int a)
{
dwords x;
x.all = a;
if (x.s.low == 0)
{
if (x.s.high == 0)
return 0;
return __builtin_ctz(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
}
return __builtin_ctz(x.s.low) + 1;
}
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