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cc65/src/common/bitops.c
uz 53dd513176 This commit was generated by cvs2svn to compensate for changes in r2,
which included commits to RCS files with non-trunk default branches.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00

129 lines
3.2 KiB
C

/*****************************************************************************/
/* */
/* bitops.c */
/* */
/* Single bit operations */
/* */
/* */
/* */
/* (C) 1998 Ullrich von Bassewitz */
/* Wacholderweg 14 */
/* D-70597 Stuttgart */
/* EMail: uz@musoftware.de */
/* */
/* */
/* 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. */
/* */
/*****************************************************************************/
#include "bitops.h"
/*****************************************************************************/
/* Code */
/*****************************************************************************/
unsigned BitFind (unsigned long Val)
/* Find the first bit that is set in Val. Val must *not* be zero */
{
unsigned long Mask;
unsigned Bit;
/* Search for the bits */
Mask = 1;
Bit = 0;
while (1) {
if (Val & Mask) {
return Bit;
}
Mask <<= 1;
++Bit;
}
}
void BitSet (void* Data, unsigned Bit)
/* Set a bit in a char array */
{
/* Make a char pointer */
unsigned char* D = Data;
/* Set the bit */
D [Bit / 8] |= 0x01 << (Bit % 8);
}
void BitReset (void* Data, unsigned Bit)
/* Reset a bit in a char array */
{
/* Make a char pointer */
unsigned char* D = Data;
/* Set the bit */
D [Bit / 8] &= ~(0x01 << (Bit % 8));
}
int BitIsSet (void* Data, unsigned Bit)
/* Check if a bit is set in a char array */
{
/* Make a char pointer */
unsigned char* D = Data;
/* Check the bit state */
return (D [Bit / 8] & (0x01 << (Bit % 8))) != 0;
}
int BitIsReset (void* Data, unsigned Bit)
/* Check if a bit is reset in a char array */
{
/* Make a char pointer */
unsigned char* D = Data;
/* Check the bit state */
return (D [Bit / 8] & (0x01 << (Bit % 8))) == 0;
}
void BitMerge (void* Target, const void* Source, unsigned Size)
/* Merge the bits of two char arrays (that is, do an or for the full array) */
{
/* Make char arrays */
unsigned char* T = Target;
const unsigned char* S = Source;
/* Merge the arrays */
while (Size--) {
*T++ |= *S++;
}
}