src/arch/x86/regs/float.cc

/*
 * Copyright (c) 2007 The Hewlett-Packard Development Company
 * All rights reserved.
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
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 * modified or unmodified, in source code or in binary form.
 *
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 * 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
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include <sstream>

#include "arch/x86/isa.hh"
#include "arch/x86/regs/misc.hh"

namespace gem5
{
namespace X86ISA
{

std::string
FlatFloatRegClassOps::regName(const RegId &id) const
{
    std::ostringstream ss;

    RegIndex reg_idx = id.index();

    if (reg_idx < NumMMXRegs) {
        ccprintf(ss, "%%mmx%d", reg_idx);
        return ss.str();
    }
    reg_idx -= NumMMXRegs;
    if (reg_idx < NumXMMRegs * 2) {
        ccprintf(ss, "%%xmm%d_%s", reg_idx / 2,
                (reg_idx % 2) ? "high": "low");
        return ss.str();
    }
    reg_idx -= NumXMMRegs * 2;
    if (reg_idx < NumMicroFpRegs) {
        ccprintf(ss, "%%ufp%d", reg_idx);
        return ss.str();
    }
    reg_idx -= NumMicroFpRegs;
    ccprintf(ss, "%%st(%d)", reg_idx);

    return ss.str();
}

RegId
FloatRegClassOps::flatten(const BaseISA &isa, const RegId &id) const
{
    RegIndex idx = id.index();

    if (idx >= float_reg::NumRegs) {
        auto &x86_isa = static_cast<const X86ISA::ISA &>(isa);
        auto x87_top = x86_isa.readMiscRegNoEffect(misc_reg::X87Top);
        idx = float_reg::stack(idx - float_reg::NumRegs, x87_top);
    }

    return {flatFloatRegClass, idx};
}

} // namespace X86ISA
} // namespace gem5