1 /* ===-- ffsti2.c - Implement __ffsti2 -------------------------------------===
2  *
3  *                     The LLVM Compiler Infrastructure
4  *
5  * This file is dual licensed under the MIT and the University of Illinois Open
6  * Source Licenses. See LICENSE.TXT for details.
7  *
8  * ===----------------------------------------------------------------------===
9  *
10  * This file implements __ffsti2 for the compiler_rt library.
11  *
12  * ===----------------------------------------------------------------------===
13  */
14 
15 #include "int_lib.h"
16 
17 #ifdef CRT_HAS_128BIT
18 
19 /* Returns: the index of the least significant 1-bit in a, or
20  * the value zero if a is zero. The least significant bit is index one.
21  */
22 
23 COMPILER_RT_ABI si_int
__ffsti2(ti_int a)24 __ffsti2(ti_int a)
25 {
26     twords x;
27     x.all = a;
28     if (x.s.low == 0)
29     {
30         if (x.s.high == 0)
31             return 0;
32         return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT);
33     }
34     return __builtin_ctzll(x.s.low) + 1;
35 }
36 
37 #endif /* CRT_HAS_128BIT */
38