10b57cec5SDimitry Andric //===-- ffsti2.c - Implement __ffsti2 -------------------------------------===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric // 90b57cec5SDimitry Andric // This file implements __ffsti2 for the compiler_rt library. 100b57cec5SDimitry Andric // 110b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 120b57cec5SDimitry Andric 130b57cec5SDimitry Andric #include "int_lib.h" 140b57cec5SDimitry Andric 150b57cec5SDimitry Andric #ifdef CRT_HAS_128BIT 160b57cec5SDimitry Andric 170b57cec5SDimitry Andric // Returns: the index of the least significant 1-bit in a, or 180b57cec5SDimitry Andric // the value zero if a is zero. The least significant bit is index one. 190b57cec5SDimitry Andric __ffsti2(ti_int a)20*5ffd83dbSDimitry AndricCOMPILER_RT_ABI int __ffsti2(ti_int a) { 210b57cec5SDimitry Andric twords x; 220b57cec5SDimitry Andric x.all = a; 230b57cec5SDimitry Andric if (x.s.low == 0) { 240b57cec5SDimitry Andric if (x.s.high == 0) 250b57cec5SDimitry Andric return 0; 260b57cec5SDimitry Andric return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT); 270b57cec5SDimitry Andric } 280b57cec5SDimitry Andric return __builtin_ctzll(x.s.low) + 1; 290b57cec5SDimitry Andric } 300b57cec5SDimitry Andric 310b57cec5SDimitry Andric #endif // CRT_HAS_128BIT 32