src/arch/mips/regfile/float_regfile.cc

/*
 * Copyright (c) 2003-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Gabe Black
 *          Korey Sewell
 */

#include "arch/mips/regfile/float_regfile.hh"
#include "sim/serialize.hh"

using namespace MipsISA;
using namespace std;

void
FloatRegFile::clear()
{
    bzero(&regs, sizeof(regs));
}

double
FloatRegFile::readReg(int floatReg, int width, unsigned tid)
{
    switch(width)
    {
      case SingleWidth:
        {
            void *float_ptr = &regs[floatReg];
            return *(float *) float_ptr;
        }

      case DoubleWidth:
        {
            uint64_t double_val = (FloatReg64)regs[floatReg + 1] << 32 | regs[floatReg];
            void *double_ptr = &double_val;
            return *(double *) double_ptr;
        }

      default:
        panic("Attempted to read a %d bit floating point register!", width);
    }
}

FloatRegBits
FloatRegFile::readRegBits(int floatReg, int width, unsigned tid)
{
    if (floatReg < NumFloatArchRegs - 1) {
        switch(width)
        {
          case SingleWidth:
            return regs[floatReg];

          case DoubleWidth:
            return (FloatReg64)regs[floatReg + 1] << 32 | regs[floatReg];

          default:
            panic("Attempted to read a %d bit floating point register!", width);
        }
    } else {
        if (width > SingleWidth)
            assert("Control Regs are only 32 bits wide");

        return regs[floatReg];
    }
}

Fault
FloatRegFile::setReg(int floatReg, const FloatRegVal &val, int width, unsigned tid)
{
    using namespace std;
    switch(width)
    {
      case SingleWidth:
        {
            float temp = val;
            void *float_ptr = &temp;
            regs[floatReg] = *(FloatReg32 *) float_ptr;
            break;
        }

      case DoubleWidth:
        {
            const void *double_ptr = &val;
            FloatReg64 temp_double = *(FloatReg64 *) double_ptr;
            regs[floatReg + 1] = bits(temp_double, 63, 32);
            regs[floatReg] = bits(temp_double, 31, 0);
            break;
        }

      default:
        panic("Attempted to read a %d bit floating point register!", width);
    }

    return NoFault;
}

Fault
FloatRegFile::setRegBits(int floatReg, const FloatRegBits &val, int width, unsigned tid)
{
    using namespace std;

    switch(width)
    {
      case SingleWidth:
        regs[floatReg] = val;
        break;

      case DoubleWidth:
        regs[floatReg + 1] = bits(val, 63, 32);
        regs[floatReg] = bits(val, 31, 0);
        break;

      default:
        panic("Attempted to read a %d bit floating point register!", width);
    }
    return NoFault;
}

void
FloatRegFile::serialize(std::ostream &os)
{
    SERIALIZE_ARRAY(regs, NumFloatRegs);
}

void
FloatRegFile::unserialize(Checkpoint *cp, const std::string &section)
{
    UNSERIALIZE_ARRAY(regs, NumFloatRegs);
}