gravity_ircode.h

//
//  gravity_ircode.h
//  gravity
//
//  Created by Marco Bambini on 06/11/14.
//  Copyright (c) 2014 CreoLabs. All rights reserved.
//

#ifndef __GRAVITY_IRCODE__
#define __GRAVITY_IRCODE__

// References:
// https://www.usenix.org/legacy/events/vee05/full_papers/p153-yunhe.pdf
// http://www.lua.org/doc/jucs05.pdf
//
// In a stack-based VM, a local variable is accessed using an index, and the operand stack is accessed via the stack pointer.
// In a register-based VM both the local variables and operand stack can be considered as virtual registers for the method.
// There is a simple mapping from stack locations to register numbers, because the height and contents of the VM operand stack
// are known at any point in a program.
//
// All values on the operand stack can be considered as temporary variables (registers) for a method and therefore are short-lived.
// Their scope of life is between the instructions that push them onto the operand stack and the instruction that consumes
// the value on the operand stack. On the other hand, local variables (also registers) are long-lived and their life scope is
// the time of method execution.

#include "debug_macros.h"
#include "gravity_opcodes.h"
#include "gravity_array.h"

#define IRCODE_LATEST	UINT32_MAX

typedef enum {
		NO_TAG = 0,
		INT_TAG,
		DOUBLE_TAG,
		LABEL_TAG,
		SKIP_TAG,
		RANGE_INCLUDE_TAG,
		RANGE_EXCLUDE_TAG,
		PRAGMA_OPTIMIZATION
} optag_t;

typedef struct {
	opcode_t	op;
	optag_t		tag;
	int32_t		p1;
	int32_t		p2;
	int32_t		p3;
	union {
		double		d;		//	tag is DOUBLE_TAG
		int64_t		n;		//	tag is INT_TAG
	};
} inst_t;

typedef struct ircode_t ircode_t;

ircode_t	*ircode_create (uint16_t nlocals);
void		ircode_free (ircode_t *code);
uint32_t	ircode_count (ircode_t *code);
uint32_t	ircode_ntemps (ircode_t *code);
inst_t		*ircode_get (ircode_t *code, uint32_t index);
void		ircode_dump (void *code);
void		ircode_push_context (ircode_t *code);
void		ircode_pop_context (ircode_t *code);
bool		ircode_iserror (ircode_t *code);
void		ircode_patch_init (ircode_t *code, uint16_t index);

uint32_t	ircode_newlabel (ircode_t *code);
void		ircode_setlabel_true (ircode_t *code, uint32_t nlabel);
void		ircode_setlabel_false (ircode_t *code, uint32_t nlabel);
void		ircode_unsetlabel_true (ircode_t *code);
void		ircode_unsetlabel_false (ircode_t *code);
uint32_t	ircode_getlabel_true (ircode_t *code);
uint32_t	ircode_getlabel_false (ircode_t *code);
void		ircode_marklabel (ircode_t *code, uint32_t nlabel);

void		inst_setskip (inst_t *inst);
uint8_t		opcode_numop (opcode_t op);

void		ircode_add (ircode_t *code, opcode_t op, uint32_t p1, uint32_t p2, uint32_t p3);
void		ircode_add_tag (ircode_t *code, opcode_t op, uint32_t p1, uint32_t p2, uint32_t p3, optag_t tag);
void		ircode_add_array (ircode_t *code, opcode_t op, uint32_t p1, uint32_t p2, uint32_t p3, uint32_r r);
void		ircode_add_double (ircode_t *code, double d);
void		ircode_add_int (ircode_t *code, int64_t n);
void		ircode_add_constant (ircode_t *code, uint32_t index);
void		ircode_add_skip (ircode_t *code);
void		ircode_set_index (uint32_t index, ircode_t *code, opcode_t op, uint32_t p1, uint32_t p2, uint32_t p3);
void		ircode_setarray_index (uint32_t index, ircode_t *code, opcode_t op, uint32_t p1, uint32_t p2, uint32_t p3, uint32_r r);

bool		ircode_register_istemp (ircode_t *code, uint32_t n);
uint32_t	ircode_register_push_temp (ircode_t *code);
uint32_t	ircode_register_push (ircode_t *code, uint32_t nreg);
uint32_t	ircode_register_pop (ircode_t *code);
uint32_t	ircode_register_pop_protect (ircode_t *code, bool protect);
void		ircode_register_protect (ircode_t *code, uint32_t nreg);
uint32_t	ircode_register_last (ircode_t *code);
uint32_t	ircode_register_count (ircode_t *code);
void		ircode_register_clean (ircode_t *code, uint32_t nreg);
void		ircode_register_dump (ircode_t *code);

#endif