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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-exception6//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_128BIT16 17// Returns: the index of the least significant 1-bit in a, or18// the value zero if a is zero. The least significant bit is index one.19 20COMPILER_RT_ABI 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_128BIT32