#ifndef ralloc_H
#define ralloc_H

#include <stdio.h>

#include "riscv.h"
#include "types.h"

/* Number of available registers. */
#define RALLOC_NREGS 15

/* Order of registers to allocate. */
extern const reg_t ralloc_regs[RALLOC_NREGS];

/* Register allocator context. */
typedef struct {
    bool regs[RALLOC_NREGS]; /* Registers status. */
} ralloc_t;

/* Return a new register allocator. */
ralloc_t ralloc(void);
/* Allocate and return a new register. */
reg_t ralloc_next(ralloc_t *ra);
/* Allocate and return a new register, avoiding `r` when possible. */
reg_t ralloc_next_except(ralloc_t *ra, reg_t r);
/* Free the given register. */
void ralloc_free(ralloc_t *ra, reg_t r);
/* Free all allocated registers. */
void ralloc_free_all(ralloc_t *ra);
/* Returns whether this register is free to reserve. */
bool ralloc_is_free(ralloc_t *ra, reg_t r);
/* Reserve a register. Fails if the register is already reserved. */
void ralloc_reserve(ralloc_t *ra, reg_t r);
/* Save the register allocation state. */
void ralloc_save(ralloc_t *ra, bool *reserved);
/* Restore the register allocation state. */
void ralloc_restore(ralloc_t *ra, bool *reserved);

#endif