| //===-- ffsti2.c - Implement __ffsti2 -------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements __ffsti2 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "int_lib.h" |
| |
| #ifdef CRT_HAS_128BIT |
| |
| // Returns: the index of the least significant 1-bit in a, or |
| // the value zero if a is zero. The least significant bit is index one. |
| |
| COMPILER_RT_ABI si_int __ffsti2(ti_int a) { |
| twords x; |
| x.all = a; |
| if (x.s.low == 0) { |
| if (x.s.high == 0) |
| return 0; |
| return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT); |
| } |
| return __builtin_ctzll(x.s.low) + 1; |
| } |
| |
| #endif // CRT_HAS_128BIT |
