mirror of https://github.com/TomHarte/CLK.git
90 lines
1.5 KiB
C++
90 lines
1.5 KiB
C++
//
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// RegisterSizes.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 14/05/2017.
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// Copyright 2017 Thomas Harte. All rights reserved.
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//
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#pragma once
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#include <cstdint>
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#pragma pack(push, 1)
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// Unions below assume a modern consumer architecture,
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// and that this compiler offers C-style anonymous structs.
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namespace CPU {
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/// Provides access to all intermediate parts of a larger int.
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template <typename Full, typename Half> union alignas(Full) alignas(Half) RegisterPair {
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RegisterPair(Full v) : full(v) {}
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RegisterPair() = default;
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Full full;
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#if TARGET_RT_BIG_ENDIAN
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struct {
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Half high, low;
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} halves;
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#else
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struct {
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Half low, high;
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} halves;
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#endif
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};
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using RegisterPair16 = RegisterPair<uint16_t, uint8_t>;
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using RegisterPair32 = RegisterPair<uint32_t, RegisterPair16>;
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/// Provides access to lower portions of a larger int.
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template <typename IntT> union SlicedInt {};
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template <> union SlicedInt<uint16_t> {
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struct {
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uint16_t w;
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};
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struct {
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#if TARGET_RT_BIG_ENDIAN
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uint8_t __padding[1];
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#endif
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uint8_t b;
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};
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};
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template <> union SlicedInt<uint32_t> {
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struct {
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uint32_t l;
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};
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struct {
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#if TARGET_RT_BIG_ENDIAN
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uint16_t __padding[1];
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#endif
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uint16_t w;
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};
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struct {
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#if TARGET_RT_BIG_ENDIAN
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uint8_t __padding[3];
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#endif
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uint8_t b;
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};
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struct {
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#if TARGET_RT_BIG_ENDIAN
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SlicedInt<uint16_t> high, low;
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#else
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SlicedInt<uint16_t> low, high;
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#endif
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};
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};
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using SlicedInt16 = SlicedInt<uint16_t>;
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using SlicedInt32 = SlicedInt<uint32_t>;
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}
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#pragma pack(pop)
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