#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "chelper.h"
#include "tree.h"

#if 0
#define DDCHELP
#endif

#define REGLEN 4
static char *regs64[] = {"rax", "r10", "r11", "r9"};
static char *regs8l[] = {"al", "r10b", "r11b", "r9b"};

/* ja, dirty.. */
static char *akt_func_name = (char*) NULL;
static char need_stack = 0;
static int call_s = 0;

void func_header(char *s, int vars, int parms, int call)
{
	printf("\t.globl %1$s\n\t.type %1$s, @function\n%1$s:\n", s);
	printf("\t//vars: %i, parms: %i, call(bool): %i\n", vars, parms, call);
	akt_func_name = s;

	need_stack = (vars || parms) && call;
	call_s = call;
	if(need_stack && (call != -1)) {
		printf("\tenter $%d, $0\n", 8*(vars + parms + 2 /* fuer rax und r10 */));
	}
}

char *get_func_name(void)
{
	return akt_func_name;
}

void func_footer(void)
{
	if(call_s != -1) {
		if(need_stack)
			printf("\tleave\n");
		printf("\tret\n\n\n");
	}
}

void move(char *src, char *dst)
{
	if(src == (char*) NULL) return;
	if(strcmp(src,dst) != 0) {
		printf("\tmovq %%%s, %%%s\n", src, dst);
	}
}

void moveimm(long imm, char *dst)
{
	char buf[100];
	sprintf(buf, "$%d", imm);
	printf("\tmovq %s, %%%s\n", buf, dst);
}

char *next_reg(char *s, int params)
{
	int i = 0;
	if (s != (char*) NULL) {
		while(strcmp(s, regs64[i]) != 0) {
			i = (i+1) % REGLEN;
		}
		i = (i+1) % REGLEN;
	}
#ifdef DDCHELP
	fprintf(stderr, "next_reg(): %s (bei %i parameter)\n", regs64[i], params);
#endif
	return regs64[i];
}

char *reg_64to8l(char *s)
{
	int i = 0;
	if (s != (char*) NULL) {
		while(strcmp(s, regs64[i]) != 0) {
			i = (i+1) % REGLEN;
		}
		return regs8l[i];
	}
	fprintf(stderr, "reg_64to8l(): sollte nicht passieren\n");
	exit(4);
}

char *param_reg(int num)
{
	char *regs[] = {"rdi", "rsi", "rdx", "rcx", "r8", "r9", "r11"};
	return regs[num];
}