inst_res.hh

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 * Copyright (c) 2016-2017 ARM Limited
 * 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
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#ifndef __CPU_INST_RES_HH__
#define __CPU_INST_RES_HH__
 
#include <type_traits>
 
#include "arch/generic/types.hh"
#include "arch/generic/vec_reg.hh"
 
namespace gem5
{
 
class InstResult
{
  public:
    union MultiResult
    {
        uint64_t integer;
        double dbl;
        TheISA::VecRegContainer vector;
        TheISA::VecElem vecElem;
        TheISA::VecPredRegContainer pred;
        MultiResult() {}
    };
 
    enum class ResultType
    {
        Scalar,
        VecElem,
        VecReg,
        VecPredReg,
        NumResultTypes,
        Invalid
    };
 
  private:
    MultiResult result;
    ResultType type;
 
  public:
    InstResult() : type(ResultType::Invalid) { }
    InstResult(const InstResult &) = default;
    template<typename T>
    explicit InstResult(T i, const ResultType& t) : type(t) {
        static_assert(std::is_integral<T>::value ^
                        std::is_floating_point<T>::value,
                "Parameter type is neither integral nor fp, or it is both");
        if (std::is_integral<T>::value) {
            result.integer = i;
        } else if (std::is_floating_point<T>::value) {
            result.dbl = i;
        }
    }
    explicit InstResult(const TheISA::VecRegContainer& v, const ResultType& t)
        : type(t) { result.vector = v; }
    explicit InstResult(const TheISA::VecPredRegContainer& v,
            const ResultType& t)
        : type(t) { result.pred = v; }
 
    InstResult& operator=(const InstResult& that) {
        type = that.type;
        switch (type) {
        /* Given that misc regs are not written to, there may be invalids in
         * the result stack. */
        case ResultType::Invalid:
            break;
        case ResultType::Scalar:
            result.integer = that.result.integer;
            break;
        case ResultType::VecElem:
            result.vecElem = that.result.vecElem;
            break;
        case ResultType::VecReg:
            result.vector = that.result.vector;
            break;
        case ResultType::VecPredReg:
            result.pred = that.result.pred;
            break;
 
        default:
            panic("Assigning result from unknown result type");
            break;
        }
        return *this;
    }
    bool operator==(const InstResult& that) const {
        if (this->type != that.type)
            return false;
        switch (type) {
        case ResultType::Scalar:
            return result.integer == that.result.integer;
        case ResultType::VecElem:
            return result.vecElem == that.result.vecElem;
        case ResultType::VecReg:
            return result.vector == that.result.vector;
        case ResultType::VecPredReg:
            return result.pred == that.result.pred;
        case ResultType::Invalid:
            return false;
        default:
            panic("Unknown type of result: %d\n", (int)type);
        }
    }
 
    bool operator!=(const InstResult& that) const {
        return !operator==(that);
    }
 
    bool isScalar() const { return type == ResultType::Scalar; }
    bool isVector() const { return type == ResultType::VecReg; }
    bool isVecElem() const { return type == ResultType::VecElem; }
    bool isPred() const { return type == ResultType::VecPredReg; }
    bool isValid() const { return type != ResultType::Invalid; }
    const uint64_t&
    asInteger() const
    {
        assert(isScalar());
        return result.integer;
    }
 
    const uint64_t&
    asIntegerNoAssert() const
    {
        return result.integer;
    }
    const TheISA::VecRegContainer&
    asVector() const
    {
        panic_if(!isVector(), "Converting scalar (or invalid) to vector!!");
        return result.vector;
    }
    const TheISA::VecElem&
    asVectorElem() const
    {
        panic_if(!isVecElem(), "Converting scalar (or invalid) to vector!!");
        return result.vecElem;
    }
 
    const TheISA::VecPredRegContainer&
    asPred() const
    {
        panic_if(!isPred(), "Converting scalar (or invalid) to predicate!!");
        return result.pred;
    }
 
};
 
} // namespace gem5
 
#endif // __CPU_INST_RES_HH__