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

#if 0
#define DDCHELP
#endif

#define REGLEN 5
static char *regsppc[] = {"14", "15", "16", "17", "18"};

/* ja, dirty.. */
static char *akt_func_name = (char*) NULL;
static char need_stack = 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;
	if(need_stack) {
		/* save the link register */
		printf("\tmflr 0; stw 0,-8(1)\n");
		/* create the stack */
		printf("\tstwu 1, -80(1)\n");
	}
}

char *get_func_name(void)
{
	return akt_func_name;
}

void func_footer(void)
{
	if(need_stack) {
		/* remove stack frame */
		printf("\taddi 1,1,80\n");
		/* restore link register */
		printf("\tlwz 0,-8(1); mtlr 0\n");
	}
	printf("\tblr\n\n\n");
}

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

void moveimm(long imm, char *dst)
{
	if((imm > 65536-1) || (imm < -65536)) {
		/* high word */
		printf("\tlis %s,%d@ha\n", dst, imm);
		/* low word */
		printf("\taddi %s,%s,%d@l\n", dst, dst, imm);
	} else {
		/* just low word */
		printf("\tli %s,%d@l\n", dst, imm);
	}
}

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

char *reg_64to8l(char *s)
{
	fprintf(stderr, "reg_64to8l(): sollte nicht passieren\n");
	exit(4);
	return "";
}

char *param_reg(int num)
{
	char *regs[] = {"3", "4", "5", "6", "7", "8", "9", "10"};
	return regs[num];
}