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#pragma once
#include <cstdint>
#include <functional>
#include <map>
#include <optional>
#include <string>
enum ctlreg {
#define REG(N) N,
#include "ctlreg.def"
#undef REG
NUM_CTLREGS,
};
const char * const ctlreg_names[] = {
#define REG(N) #N,
#include "ctlreg.def"
#undef REG
};
const std::map<std::string, ctlreg> ctlreg_map = {
#define REG(N) { #N, N },
#include "ctlreg.def"
#undef REG
};
// FLAGS and FLAGS_SAVED
static constexpr unsigned int FLAG_DF_SHIFT = 0;
static constexpr std::uint_fast32_t FLAG_DF = 07 << FLAG_DF_SHIFT;
static constexpr unsigned int FLAG_IF_SHIFT = 3;
static constexpr std::uint_fast32_t FLAG_IF = 07 << FLAG_IF_SHIFT; // In FLAGS this is IFB, not IF
static constexpr std::uint_fast32_t FLAG_USER_MODE = 1 << 6;
static constexpr std::uint_fast32_t FLAG_INT_ENABLE = 1 << 7;
static constexpr std::uint_fast32_t FLAG_INT_INHIBIT = 1 << 8;
static constexpr std::uint_fast32_t FLAG_INT_REQUEST = 1 << 9;
static constexpr std::uint_fast32_t FLAG_GREATER_THAN = 1 << 10;
static constexpr std::uint_fast32_t FLAG_INT_ENABLE_DELAY = 1 << 12; // n.b. this is not a "visible" flag
// TT_BITS
static constexpr std::uint_fast32_t TTI_FLAG = 1 << 0;
static constexpr std::uint_fast32_t TTO_TX = 1 << 1;
static constexpr std::uint_fast32_t TTO_FLAG = 1 << 2;
static constexpr unsigned int TTI_DATA_SHIFT = 8;
static constexpr std::uint_fast32_t TTI_DATA = 0xff << TTI_DATA_SHIFT;
static constexpr unsigned int TTO_DATA_SHIFT = 16;
static constexpr std::uint_fast32_t TTO_DATA = 0xff << TTO_DATA_SHIFT;
// TT_FLAGS
static constexpr std::uint_fast32_t TTF_INT_ENABLE = 1 << 0;
static constexpr std::uint_fast32_t TTF_STATUS_ENABLE = 1 << 1;
struct instruction_context {
// Known statically at decode time
bool need_indirect_load = false; // final_address = mem[init_address]
bool need_autoinc_store = false; // mem[init_address] += 1
bool need_exec_load = false; // data = mem[final_address]
bool need_read_acc = false; // acc = %acc
bool need_read_link = false; // link = %link
bool need_read_mq = false; // mq = %mq
std::optional<ctlreg> read_ctlreg; // ctlval = %[read_ctlreg]
bool need_write_acc = false; // %acc = acc
bool need_write_link = false; // %link = link
bool need_write_mq = false; // %mq = mq
std::optional<ctlreg> write_ctlreg; // %[write_ctlreg] = ctlval
bool need_exec_store = false; // mem[final_address] = data
bool possibly_redirects = false; // %pc = next_pc
std::function<void(instruction_context &ctx)> ef;
void execute() { ef(*this); }
// May change over the lifetime of the instruction execution
unsigned int next_pc; // includes IF
std::optional<unsigned int> init_address; // includes DF
std::optional<unsigned int> final_address; // includes DF
std::optional<std::uint_fast32_t> ctlval; // control registers may be larger than 16 bits (e.g. TT_BITS)
std::optional<unsigned int> data;
std::optional<unsigned int> acc;
std::optional<bool> link;
std::optional<unsigned int> mq;
};
instruction_context decode(std::uint_fast32_t flags, unsigned int pc, unsigned int bits, bool interrupt);
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