xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/ffssi2.c (revision e25152834cdf3b353892835a4f3b157e066a8ed4)
10b57cec5SDimitry Andric //===-- ffssi2.c - Implement __ffssi2 -------------------------------------===//
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 __ffssi2 for the compiler_rt library.
100b57cec5SDimitry Andric //
110b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
120b57cec5SDimitry Andric 
130b57cec5SDimitry Andric #include "int_lib.h"
140b57cec5SDimitry Andric 
150b57cec5SDimitry Andric // Returns: the index of the least significant 1-bit in a, or
160b57cec5SDimitry Andric // the value zero if a is zero. The least significant bit is index one.
170b57cec5SDimitry Andric 
__ffssi2(si_int a)18*5ffd83dbSDimitry Andric COMPILER_RT_ABI int __ffssi2(si_int a) {
190b57cec5SDimitry Andric   if (a == 0) {
200b57cec5SDimitry Andric     return 0;
210b57cec5SDimitry Andric   }
22*5ffd83dbSDimitry Andric   return ctzsi(a) + 1;
230b57cec5SDimitry Andric }
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