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/*! \file include/sys/bitops.h
\brief Internal Interface: H8/300 bit operations
\author Markus L. Noga <markus@noga.de>
*/
/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License
* at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and
* limitations under the License.
*
* The Original Code is legOS code, released October 17, 1999.
*
* The Initial Developer of the Original Code is Markus L. Noga.
* Portions created by Markus L. Noga are Copyright (C) 1999
* Markus L. Noga. All Rights Reserved.
*
* Contributor(s): Markus L. Noga <markus@noga.de>
*/
#ifndef __sys_bitops_h__
#define __sys_bitops_h__
#ifdef __cplusplus
extern "C" {
#endif
///////////////////////////////////////////////////////////////////////
//
// Functions
//
///////////////////////////////////////////////////////////////////////
// g++ warns about __asm__ const. we define the problem away.
// the CXX symbol is predefined in the Makefile
//
#if defined(CXX) || __GNUC__ >= 3
# define ASMCONST
#else
# define ASMCONST const
#endif
//
// the H8/300 processor offers many useful bit operations.
// sometimes, we have to help gcc to realize their full
// potential.
//
// the bit operations don't alter cc except for bld
//
//! set a single bit in memory
/*! *((char*)byte)|=(1<<bit)
*/
#define bit_set(byte,bit) \
__asm__ ASMCONST ( "bset %0,@%1\n" : : "i" (bit),"r" (byte))
//! clear a single bit in memory
/*! ((char*)byte)&=~(1<<bit)
*/
#define bit_clear(byte,bit) \
__asm__ ASMCONST ( "bclr %0,@%1\n" : : "i" (bit),"r" (byte))
//! load a single bit from a mask to the carry flag
/*! carry=mask & (1<<bit)
*/
#define bit_load(mask,bit) \
__asm__ ASMCONST ( "bld %0,%1l\n" : : "i" (bit),"r" (mask):"cc")
//! load the inverse of a single bit from a mask to the carry flag
/*! carry=mask & inverse of (1<<bit)
*/
#define bit_iload(mask,bit) \
__asm__ ASMCONST ( "bild %0,%1l\n" : : "i" (bit),"r" (mask):"cc")
//! store the carry flag to a single single bit in memory
/*! *((char*)byte)= ( (*((char*)byte)) & (~(1<<bit)) ) | (carry<<bit)
*/
#define bit_store(byte,bit) \
__asm__ ASMCONST ( "bst %0,@%1\n" : : "i" (bit),"r" (byte))
#ifdef __cplusplus
}
#endif
#endif // __sys_bitops_h__
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