xref: /openbsd-src/gnu/llvm/compiler-rt/lib/builtins/ffssi2.c (revision 1f9cb04fc6f537ca6cf5a53c28927340cba218a2)

//===-- ffssi2.c - Implement __ffssi2 -------------------------------------===//
//
// 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 __ffssi2 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//

#include "int_lib.h"

// 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 int __ffssi2(si_int a) {
  if (a == 0) {
    return 0;
  }
  return ctzsi(a) + 1;
}