1353358Sdim//===-- ffsti2.c - Implement __ffsti2 -------------------------------------===// 2353358Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6353358Sdim// 7353358Sdim//===----------------------------------------------------------------------===// 8353358Sdim// 9353358Sdim// This file implements __ffsti2 for the compiler_rt library. 10353358Sdim// 11353358Sdim//===----------------------------------------------------------------------===// 12276789Sdim 13276789Sdim#include "int_lib.h" 14276789Sdim 15276789Sdim#ifdef CRT_HAS_128BIT 16276789Sdim 17353358Sdim// Returns: the index of the least significant 1-bit in a, or 18353358Sdim// the value zero if a is zero. The least significant bit is index one. 19276789Sdim 20353358SdimCOMPILER_RT_ABI si_int __ffsti2(ti_int a) { 21353358Sdim twords x; 22353358Sdim x.all = a; 23353358Sdim if (x.s.low == 0) { 24353358Sdim if (x.s.high == 0) 25353358Sdim return 0; 26353358Sdim return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT); 27353358Sdim } 28353358Sdim return __builtin_ctzll(x.s.low) + 1; 29276789Sdim} 30276789Sdim 31353358Sdim#endif // CRT_HAS_128BIT 32