1 /* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===
3 * The LLVM Compiler Infrastructure
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
8 * ===----------------------------------------------------------------------===
10 * This file implements __ctzdi2 for the compiler_rt library.
12 * ===----------------------------------------------------------------------===
17 /* Returns: the number of trailing 0-bits */
19 /* Precondition: a != 0 */
21 COMPILER_RT_ABI si_int
26 const si_int f
= -(x
.s
.low
== 0);
27 return __builtin_ctz((x
.s
.high
& f
) | (x
.s
.low
& ~f
)) +
28 (f
& ((si_int
)(sizeof(si_int
) * CHAR_BIT
)));