// Commander X16 Emulator

// Instruction reference data for the debugger.

//

// disasm.c can render an instruction, but it carries no description of what an

// instruction *does*: no summary, no flag effects, no "will this branch be

// taken". The debug UI wants all of that for its hover tooltips, so it lives

// here, keyed by mnemonic rather than by opcode (the mnemonic is what the user

// hovers in a source listing, and it is what disasm.c already produces).

#ifndef _INSN_INFO_H_

#define _INSN_INFO_H_

#include <stdbool.h>

#include <stdint.h>

#ifdef __cplusplus

extern "C" {

#endif

// Status bits an instruction can affect, for insn_info_t.flags_set.

#define INSN_FLAG_N 0x80

#define INSN_FLAG_V 0x40

#define INSN_FLAG_M 0x20

#define INSN_FLAG_X 0x10

#define INSN_FLAG_D 0x08

#define INSN_FLAG_I 0x04

#define INSN_FLAG_Z 0x02

#define INSN_FLAG_C 0x01

// What kind of instruction this is, so the debugger can decide what extra

// information is worth predicting.

typedef enum {

	INSN_KIND_OTHER = 0,

	INSN_KIND_LOAD,        // reads memory into a register

	INSN_KIND_STORE,       // writes a register to memory

	INSN_KIND_TRANSFER,    // register to register

	INSN_KIND_ALU,         // arithmetic / logic

	INSN_KIND_SHIFT,

	INSN_KIND_COMPARE,

	INSN_KIND_BRANCH,      // conditional relative branch

	INSN_KIND_JUMP,        // unconditional jump/call

	INSN_KIND_RETURN,

	INSN_KIND_STACK,

	INSN_KIND_FLAG,        // sets/clears a status bit

	INSN_KIND_INCDEC,

	INSN_KIND_BIT,

	INSN_KIND_INTERRUPT,

	INSN_KIND_NOP,

} insn_kind_t;

typedef struct {

	const char *mnemonic;   // lower case, as disasm.c emits

	const char *title;      // e.g. "Load Accumulator"

	const char *summary;    // one line of what it does

	insn_kind_t kind;

	uint8_t     flags_set;  // INSN_FLAG_* bits this instruction can change

	// For branches: the status bit tested and the value it must have for the

	// branch to be taken. Zero for everything else.

	uint8_t     branch_flag;

	bool        branch_when_set;

} insn_info_t;

// Look up by mnemonic (case-insensitive). NULL if unknown.

const insn_info_t *insn_info_lookup(const char *mnemonic);

// Render "N V - - - - Z C"-style text listing the flags an instruction touches.

// Writes at most `max` bytes including the terminator. Empty when none.

void insn_info_flag_text(uint8_t flags_set, char *out, unsigned int max);

#ifdef __cplusplus

}

#endif

#endif