Initial commit of OpenSPARC T2 architecture model.

[OpenSPARC-T2-SAM] / sam-t2 / sam / cpus / vonk / bl / lib / ecc / src / BL_BitUtility.h

/*
* ========== Copyright Header Begin ==========================================
* 
* OpenSPARC T2 Processor File: BL_BitUtility.h
* Copyright (c) 2006 Sun Microsystems, Inc.  All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES.
* 
* The above named program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License version 2 as published by the Free Software Foundation.
* 
* The above named 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 work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
* 
* ========== Copyright Header End ============================================
*/
/************************************************************************
**  
**  Copyright (C) 2006, Sun Microsystems, Inc.
**
**  Sun considers its source code as an unpublished, proprietary
**  trade secret and it is available only under strict license provisions.
**  This copyright notice is placed here only to protect Sun in the event 
**  the source is deemed a published work. Disassembly, decompilation,
**  or other means of reducing the object code to human readable form
**  is prohibited by the license agreement under which this code is
**  provided to the user or company in possession of this copy.
**
*************************************************************************/
#ifndef __BL_BitUtility_h__
#define __BL_BitUtility_h__

#include <unistd.h>
#include <iostream.h>

#include "BL_Types.h"

class BL_BitUtility
{
  public:	

    BL_BitUtility() {}
  
    ~BL_BitUtility() {}	  
    
    // This method calculates the parity value for up to 64 bits of
    // data using 4 XORs with a clever shift and returns a parity
    // value of either 0 or 1.
    // Data should be right justified and unused bits must be set to zero.
    static uint32_t calc_parity(uint64_t data)
    {
      uint64_t p;
      p = data ^ (data >> 32);
      p = p ^ (p >> 16);
      p = p ^ (p >> 8);
      p = p ^ (p >> 4);
      p &= 0xf;
      return (0x6996 >> p) & 1;
    }    

    // This method calculates the parity value for a BL_Uint256 (or
    // 256 bits of data).
    static uint32_t calc_parity(BL_Uint256 data)
    {
      return calc_parity(data.get(0)) ^ calc_parity(data.get(1)) ^
        calc_parity(data.get(2)) ^ calc_parity(data.get(3));
    }    

    // This method calculates the byte-by_byte parity values for a
    // 64-bit value.
    // The parities are returned packed in 8 bits. 
    static uint8_t calc_byte_parities(uint64_t data)
    {
      uint64_t p;
      p = data ^ (data >> 4);
      p = p ^ (p >> 2);
      p = p ^ (p >> 1);
      p &= 0x0101010101010101ULL;
      p |= (p >> 28);
      p |= (p >> 14);
      p |= (p >> 7);
      return p;
    }    

    // This routine can be used to set a certain number of bits within a 64 bit
    // value. The routine takes the super set, subset, starting index and 
    // ending index as its four input parameters.
    static uint64_t set_subfield(uint64_t data, uint64_t subfield, uint64_t start_offset, uint64_t end_offset)
    { 
      uint64_t width = (end_offset - start_offset) + 1;
      assert(width < 64);
      uint64_t mask = (((uint64_t(1) << width) - 1) << start_offset);
      data = (data &~ mask) | ((subfield << start_offset) & mask); 
      return data;
    }    
};


#endif