/** * Furnace Tracker - multi-system chiptune tracker * Copyright (C) 2021-2023 tildearrow and contributors * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #if defined( _MSC_VER ) #include static inline int bsr(unsigned short v) { unsigned long idx; if (_BitScanReverse(&idx,(unsigned long)v)) { return idx; } else { return -1; } } #elif defined( __GNUC__ ) static inline int bsr(unsigned short v) { if (v) { return 32 - __builtin_clz(v); } else{ return -1; } } #else static inline int bsr(unsigned short v) { unsigned short mask = 0x8000; for (int i = 15; i >= 0; --i) { if (v&mask) return (int)i; mask>>=1; } return -1; } #endif