From f97fa3dcb2db02013e6904c032a1d2d45707ee40 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 3 Jul 2023 16:52:08 +0300 Subject: lib/math: Move dvb_math.c into lib/math/int_log.c Some existing and new users may benefit from the intlog2() and intlog10() APIs, make them wide available. Reviewed-by: Mauro Carvalho Chehab Acked-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/20230619172019.21457-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Reviewed-by: Randy Dunlap Link: https://lore.kernel.org/r/20230703135211.87416-2-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown --- include/linux/int_log.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 include/linux/int_log.h (limited to 'include/linux') diff --git a/include/linux/int_log.h b/include/linux/int_log.h new file mode 100644 index 000000000000..332306202464 --- /dev/null +++ b/include/linux/int_log.h @@ -0,0 +1,65 @@ +/* + * Provides fixed-point logarithm operations. + * + * Copyright (C) 2006 Christoph Pfister (christophpfister@gmail.com) + * + * This library is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as + * published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. + */ + +#ifndef __LINUX_INT_LOG_H +#define __LINUX_INT_LOG_H + +#include + +/** + * intlog2 - computes log2 of a value; the result is shifted left by 24 bits + * + * @value: The value (must be != 0) + * + * to use rational values you can use the following method: + * + * intlog2(value) = intlog2(value * 2^x) - x * 2^24 + * + * Some usecase examples: + * + * intlog2(8) will give 3 << 24 = 3 * 2^24 + * + * intlog2(9) will give 3 << 24 + ... = 3.16... * 2^24 + * + * intlog2(1.5) = intlog2(3) - 2^24 = 0.584... * 2^24 + * + * + * return: log2(value) * 2^24 + */ +extern unsigned int intlog2(u32 value); + +/** + * intlog10 - computes log10 of a value; the result is shifted left by 24 bits + * + * @value: The value (must be != 0) + * + * to use rational values you can use the following method: + * + * intlog10(value) = intlog10(value * 10^x) - x * 2^24 + * + * An usecase example: + * + * intlog10(1000) will give 3 << 24 = 3 * 2^24 + * + * due to the implementation intlog10(1000) might be not exactly 3 * 2^24 + * + * look at intlog2 for similar examples + * + * return: log10(value) * 2^24 + */ +extern unsigned int intlog10(u32 value); + +#endif -- cgit v1.2.3 From 9ab04d7ed8bdd395b0617a1647dd475681f99151 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 3 Jul 2023 16:52:10 +0300 Subject: lib/math/int_log: Replace LGPL-2.1-or-later boilerplate with SPDX identifier Replace license boilerplate in udftime.c with SPDX identifier for LGPL-2.1-or-later. Acked-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/20230619172019.21457-4-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230703135211.87416-4-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown --- include/linux/int_log.h | 11 +---------- lib/math/int_log.c | 11 +---------- 2 files changed, 2 insertions(+), 20 deletions(-) (limited to 'include/linux') diff --git a/include/linux/int_log.h b/include/linux/int_log.h index 332306202464..0a6f58c38b61 100644 --- a/include/linux/int_log.h +++ b/include/linux/int_log.h @@ -1,17 +1,8 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ /* * Provides fixed-point logarithm operations. * * Copyright (C) 2006 Christoph Pfister (christophpfister@gmail.com) - * - * This library is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as - * published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. */ #ifndef __LINUX_INT_LOG_H diff --git a/lib/math/int_log.c b/lib/math/int_log.c index ea98fc0b3fe2..8f9da3a2ad39 100644 --- a/lib/math/int_log.c +++ b/lib/math/int_log.c @@ -1,17 +1,8 @@ +// SPDX-License-Identifier: LGPL-2.1-or-later /* * Provides fixed-point logarithm operations. * * Copyright (C) 2006 Christoph Pfister (christophpfister@gmail.com) - * - * This library is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as - * published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. */ #include -- cgit v1.2.3