38 lines
964 B
C
38 lines
964 B
C
|
/* ===-- ffsti2.c - Implement __ffsti2 -------------------------------------===
|
||
|
|
*
|
||
|
|
* 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 __ffsti2 for the compiler_rt library.
|
||
|
|
*
|
||
|
|
* ===----------------------------------------------------------------------===
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "int_lib.h"
|
||
|
|
|
||
|
|
#if __x86_64
|
||
|
|
|
||
|
|
/* 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
si_int
|
||
|
|
__ffsti2(ti_int a)
|
||
|
|
{
|
||
|
|
twords x;
|
||
|
|
x.all = a;
|
||
|
|
if (x.s.low == 0)
|
||
|
|
{
|
||
|
|
if (x.s.high == 0)
|
||
|
|
return 0;
|
||
|
|
return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT);
|
||
|
|
}
|
||
|
|
return __builtin_ctzll(x.s.low) + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* __x86_64 */
|