1*7bba6884SSandrine Bailleux /* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------=== 2*7bba6884SSandrine Bailleux * 3*7bba6884SSandrine Bailleux * The LLVM Compiler Infrastructure 4*7bba6884SSandrine Bailleux * 5*7bba6884SSandrine Bailleux * This file is dual licensed under the MIT and the University of Illinois Open 6*7bba6884SSandrine Bailleux * Source Licenses. See LICENSE.TXT for details. 7*7bba6884SSandrine Bailleux * 8*7bba6884SSandrine Bailleux * ===----------------------------------------------------------------------=== 9*7bba6884SSandrine Bailleux * 10*7bba6884SSandrine Bailleux * This file implements __ctzdi2 for the compiler_rt library. 11*7bba6884SSandrine Bailleux * 12*7bba6884SSandrine Bailleux * ===----------------------------------------------------------------------=== 13*7bba6884SSandrine Bailleux */ 14*7bba6884SSandrine Bailleux 15*7bba6884SSandrine Bailleux #include "int_lib.h" 16*7bba6884SSandrine Bailleux 17*7bba6884SSandrine Bailleux /* Returns: the number of trailing 0-bits */ 18*7bba6884SSandrine Bailleux 19*7bba6884SSandrine Bailleux /* Precondition: a != 0 */ 20*7bba6884SSandrine Bailleux 21*7bba6884SSandrine Bailleux COMPILER_RT_ABI si_int 22*7bba6884SSandrine Bailleux __ctzdi2(di_int a) 23*7bba6884SSandrine Bailleux { 24*7bba6884SSandrine Bailleux dwords x; 25*7bba6884SSandrine Bailleux x.all = a; 26*7bba6884SSandrine Bailleux const si_int f = -(x.s.low == 0); 27*7bba6884SSandrine Bailleux return __builtin_ctz((x.s.high & f) | (x.s.low & ~f)) + 28*7bba6884SSandrine Bailleux (f & ((si_int)(sizeof(si_int) * CHAR_BIT))); 29*7bba6884SSandrine Bailleux } 30