1 | /* ===-- ctzti2.c - Implement __ctzti2 -------------------------------------=== |
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 __ctzti2 for the compiler_rt library. |
11 | * |
12 | * ===----------------------------------------------------------------------=== |
13 | */ |
14 | |
15 | #include "int_lib.h" |
16 | |
17 | #ifdef CRT_HAS_128BIT |
18 | |
19 | /* Returns: the number of trailing 0-bits */ |
20 | |
21 | /* Precondition: a != 0 */ |
22 | |
23 | COMPILER_RT_ABI si_int |
24 | __ctzti2(ti_int a) |
25 | { |
26 | twords x; |
27 | x.all = a; |
28 | const di_int f = -(x.s.low == 0); |
29 | return __builtin_ctzll((x.s.high & f) | (x.s.low & ~f)) + |
30 | ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT))); |
31 | } |
32 | |
33 | #endif /* CRT_HAS_128BIT */ |
34 | |