1//===-- ffsti2.c - Implement __ffsti2 -------------------------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file implements __ffsti2 for the compiler_rt library. 10// 11//===----------------------------------------------------------------------===// 12 13#include "int_lib.h" 14 15#ifdef CRT_HAS_128BIT 16 17// Returns: the index of the least significant 1-bit in a, or 18// the value zero if a is zero. The least significant bit is index one. 19 20COMPILER_RT_ABI si_int __ffsti2(ti_int a) { 21 twords x; 22 x.all = a; 23 if (x.s.low == 0) { 24 if (x.s.high == 0) 25 return 0; 26 return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT); 27 } 28 return __builtin_ctzll(x.s.low) + 1; 29} 30 31#endif // CRT_HAS_128BIT 32