/*****************************************************************************/ /* */ /* shift.h */ /* */ /* Safe shift routines */ /* */ /* */ /* */ /* (C) 2003 Ullrich von Bassewitz */ /* Römerstraße 52 */ /* D-70794 Filderstadt */ /* EMail: uz@cc65.org */ /* */ /* */ /* This software is provided 'as-is', without any expressed or implied */ /* warranty. In no event will the authors be held liable for any damages */ /* arising from the use of this software. */ /* */ /* Permission is granted to anyone to use this software for any purpose, */ /* including commercial applications, and to alter it and redistribute it */ /* freely, subject to the following restrictions: */ /* */ /* 1. The origin of this software must not be misrepresented; you must not */ /* claim that you wrote the original software. If you use this software */ /* in a product, an acknowledgment in the product documentation would be */ /* appreciated but is not required. */ /* 2. Altered source versions must be plainly marked as such, and must not */ /* be misrepresented as being the original software. */ /* 3. This notice may not be removed or altered from any source */ /* distribution. */ /* */ /*****************************************************************************/ /* According to the C standard, shifting a data type by the number of bits it * has causes undefined behaviour. So * * unsigned long l = 1; * unsigned u =32; * l <<= u; * * maybe illegal. The functions in this module behave safely in this respect, * and they use proper casting to distinguish signed from unsigned shifts. * They are not a general purpose replacement for the shift operator! */ #ifndef SHIFT_H #define SHIFT_H #include /*****************************************************************************/ /* Code */ /*****************************************************************************/ long asl_l (long l, unsigned count); /* Arithmetic shift left l by count. */ long asr_l (long l, unsigned count); /* Arithmetic shift right l by count */ unsigned long shl_l (unsigned long l, unsigned count); /* Logical shift left l by count */ unsigned long shr_l (unsigned long l, unsigned count); /* Logical shift right l by count */ /* End of shift.h */ #endif