forked from OSchip/llvm-project
30 lines
805 B
C
30 lines
805 B
C
/* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===
|
|
*
|
|
* The LLVM Compiler Infrastructure
|
|
*
|
|
* This file is distributed under the University of Illinois Open Source
|
|
* License. See LICENSE.TXT for details.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*
|
|
* This file implements __ctzdi2 for the compiler_rt library.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*/
|
|
|
|
#include "int_lib.h"
|
|
|
|
/* Returns: the number of trailing 0-bits */
|
|
|
|
/* Precondition: a != 0 */
|
|
|
|
si_int
|
|
__ctzdi2(di_int a)
|
|
{
|
|
dwords x;
|
|
x.all = a;
|
|
const si_int f = -(x.s.low == 0);
|
|
return __builtin_ctz((x.s.high & f) | (x.s.low & ~f)) +
|
|
(f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
|
|
}
|