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} 30