1214152Sed/* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===
2214152Sed *
3214152Sed *                     The LLVM Compiler Infrastructure
4214152Sed *
5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open
6222656Sed * Source Licenses. See LICENSE.TXT for details.
7214152Sed *
8214152Sed * ===----------------------------------------------------------------------===
9214152Sed *
10214152Sed * This file implements __ctzdi2 for the compiler_rt library.
11214152Sed *
12214152Sed * ===----------------------------------------------------------------------===
13214152Sed */
14214152Sed
15214152Sed#include "int_lib.h"
16214152Sed
17214152Sed/* Returns: the number of trailing 0-bits  */
18214152Sed
19214152Sed/* Precondition: a != 0 */
20214152Sed
21222656SedCOMPILER_RT_ABI si_int
22214152Sed__ctzdi2(di_int a)
23214152Sed{
24214152Sed    dwords x;
25214152Sed    x.all = a;
26214152Sed    const si_int f = -(x.s.low == 0);
27214152Sed    return __builtin_ctz((x.s.high & f) | (x.s.low & ~f)) +
28214152Sed              (f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
29214152Sed}
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