vec_reg.hh

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 * Copyright (c) 2015-2018 ARM Limited
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 *
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 * 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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 * met: redistributions of source code must retain the above copyright
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#ifndef __ARCH_GENERIC_VEC_REG_HH__
#define __ARCH_GENERIC_VEC_REG_HH__
 
#include <array>
#include <cstdint>
#include <iostream>
#include <string>
 
#include "base/cprintf.hh"
#include "base/logging.hh"
#include "base/types.hh"
#include "sim/serialize_handlers.hh"
 
namespace gem5
{
 
constexpr unsigned MaxVecRegLenInBytes = 1ULL << 16; // 2^16 bytes
 
template <size_t SIZE>
class VecRegContainer
{
  private:
    static_assert(SIZE > 0,
            "Cannot create Vector Register Container of zero size");
    static_assert(SIZE <= MaxVecRegLenInBytes,
            "Vector Register size limit exceeded");
  public:
    static constexpr inline size_t size() { return SIZE; };
    using Container = std::array<uint8_t, SIZE>;
  private:
    // 16-byte aligned to support 128bit element view
    alignas(16) Container container;
 
  public:
    VecRegContainer() {}
    VecRegContainer(const VecRegContainer &) = default;
 
    void zero() { memset(container.data(), 0, SIZE); }
 
    VecRegContainer<SIZE>&
    operator=(const VecRegContainer<SIZE>& that)
    {
        if (&that != this)
            std::memcpy(container.data(), that.container.data(), SIZE);
        return *this;
    }
    template<size_t S2>
    inline bool
    operator==(const VecRegContainer<S2>& that) const
    {
        return SIZE == S2 &&
               !memcmp(container.data(), that.container.data(), SIZE);
    }
    template<size_t S2>
    bool
    operator!=(const VecRegContainer<S2>& that) const
    {
        return !operator==(that);
    }
 
    template <typename VecElem>
    VecElem *
    as()
    {
        static_assert(SIZE % sizeof(VecElem) == 0,
                "VecElem does not evenly divide the register size");
        return (VecElem *)container.data();
    }
 
    template <typename VecElem>
    const VecElem *
    as() const
    {
        static_assert(SIZE % sizeof(VecElem) == 0,
                "VecElem does not evenly divide the register size");
        return (VecElem *)container.data();
    }
 
    friend std::ostream&
    operator<<(std::ostream& os, const VecRegContainer<SIZE>& v)
    {
        // When printing for human consumption, break into 4 byte chunks.
        ccprintf(os, "[");
        size_t count = 0;
        for (auto& b: v.container) {
            if (count && (count % 4) == 0)
                os << "_";
            ccprintf(os, "%02x", b);
            count++;
        }
        ccprintf(os, "]");
        return os;
    }
 
    friend ShowParam<VecRegContainer<SIZE>>;
};
 
template <size_t Sz>
struct ParseParam<VecRegContainer<Sz>>
{
    static bool
    parse(const std::string &str, VecRegContainer<Sz> &value)
    {
        fatal_if(str.size() > 2 * Sz,
                 "Vector register value overflow at unserialize");
 
        for (int i = 0; i < Sz; i++) {
            uint8_t b = 0;
            if (2 * i < str.size())
                b = stoul(str.substr(i * 2, 2), nullptr, 16);
            value.template as<uint8_t>()[i] = b;
        }
        return true;
    }
};
 
template <size_t Sz>
struct ShowParam<VecRegContainer<Sz>>
{
    static void
    show(std::ostream &os, const VecRegContainer<Sz> &value)
    {
        for (auto& b: value.container)
            ccprintf(os, "%02x", b);
    }
};
struct DummyVecRegContainer
{
    RegVal filler = 0;
    bool operator == (const DummyVecRegContainer &d) const { return true; }
    bool operator != (const DummyVecRegContainer &d) const { return true; }
    template <typename VecElem>
    VecElem *as() { return nullptr; }
};
template <>
struct ParseParam<DummyVecRegContainer>
{
    static bool
    parse(const std::string &s, DummyVecRegContainer &value)
    {
        return false;
    }
};
static_assert(sizeof(DummyVecRegContainer) == sizeof(RegVal));
static inline std::ostream &
operator<<(std::ostream &os, const DummyVecRegContainer &d)
{
    return os;
}
} // namespace gem5
 
#endif /* __ARCH_GENERIC_VEC_REG_HH__ */