%{
#define BFEHAX

#define KID_REG(A) bnode->kids[A]->reg
#define KID_VAL(A) bnode->kids[A]->val
#define BN_REG bnode->reg
#define BN_VAL bnode->val

/* falls ein parameter auf der "leseseite" ist, soll das statt ein weiteres
 * register verwendet werden */
#define KIDREG2PARM(A) if(bnode->kids[A]->param_index > -1) { bnode->kids[A]->reg = param_reg(bnode->kids[A]->param_index); }

#define KIDREG2ID(A) if(bnode->kids[A]->op == O_ID && bnode->kids[A]->param_index > -1) move(param_reg(bnode->kids[A]->param_index), bnode->kids[A]->reg);

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

void gen_e_eno(struct treenode *bnode, char *instr)
{
	printf("\t//gen_e_eno(%s)\n", instr);
	KIDREG2ID(0);
	KIDREG2PARM(1);
	printf("\t%s %%%s, %%%s\n", instr, KID_REG(1), KID_REG(0));
}

void gen_e_imm(struct treenode *bnode, char *instr)
{
	printf("\t//gen_e_imm(%s)\n", instr);
	KIDREG2ID(0);
	KIDREG2ID(1);
	/* man kann sich ein move der konstante bei der multiplikation ersparen */
	if(strcmp(instr, "imulq") == 0) {
		printf("\timulq $%d, %%%s, %%%s\n", KID_VAL(1), KID_REG(0), BN_REG);
	} else {
		printf("\t%s $%d, %%%s\n", instr, KID_VAL(1), KID_REG(0));
		move(KID_REG(0), BN_REG);
	}
}

void gen_imm_eno(struct treenode *bnode, char *instr)
{
	printf("\t//gen_imm_eno(%s)\n", instr);
	KIDREG2ID(0);
	KIDREG2PARM(1);
	/* man kann sich ein move der konstante bei der multiplikation ersparen */
	if(strcmp(instr, "imulq") == 0) {
		printf("\timulq $%d, %%%s, %%%s\n", KID_VAL(0), KID_REG(1), BN_REG);
	} else if(strcmp(instr, "addq") == 0) {
		printf("\taddq $%d, %%%s\n", KID_VAL(0), BN_REG);
	} else { /* subq */
		moveimm(KID_VAL(0), BN_REG);
		printf("\t%s %%%s, %%%s\n", instr, KID_REG(1), BN_REG);
	}
}

void gen_eqless(struct treenode *bnode, char *op, short e0, short e1)
{
	printf("\t//gen_eqless_%i%i\n", e0, e1);
	if(e0) { KIDREG2PARM(0); } else { KIDREG2ID(0); }
	if(e1) { KIDREG2PARM(1); } else { KIDREG2ID(1); }

	if(e0 && e1) {
		printf("\tcmp %%%s, %%%s\n", KID_REG(1), KID_REG(0));
	} else if(e0 && !e1) {
		printf("\tcmp $%d, %%%s\n", KID_VAL(1), KID_REG(0));
	} else if(!e0 && e1) {
		if(strcmp("e", op) == 0) {
			printf("\tcmp $%d, %%%s\n", KID_VAL(0), KID_REG(1));
		} else {
			moveimm(KID_VAL(0), BN_REG);
			printf("\tcmp %%%s, %%%s\n", KID_REG(1), BN_REG);
		}
	}
	printf("\tset%s %%%s\n", op, reg_64to8l(BN_REG));
	printf("\tand $1, %%%s\n", BN_REG);
}

%}

%start begin
%term O_RET=1 O_NULL=2 O_SUB=3 O_MUL=4 O_OR=5 O_LESS=6 O_EQ=7 O_ID=8 O_ADD=9 O_NUM=10 O_FIELD=11

%%

begin: ret # 0 # printf("\n");
ret: O_RET(retexpr) # 2 # printf("\t//o_ret(expr)\n"); move(BN_REG, "rax"); func_footer();

retexpr: O_ID # 1 # printf("\t//retexpr\n"); if(bnode->param_index > -1) move(param_reg(bnode->param_index), BN_REG);
retexpr: expr

expr: O_ID # 0 #
expr: imm # 1 # moveimm(BN_VAL, BN_REG);

expr: O_SUB(expr,expr) # 1 # gen_e_eno(bnode, "subq");
expr: O_SUB(expr,imm)    # 2 # gen_e_imm(bnode, "subq");
expr: O_SUB(imm,expr)  # 2 # gen_imm_eno(bnode, "subq");

expr: O_ADD(expr,expr) # 1 # gen_e_eno(bnode, "addq");
expr: O_ADD(expr,imm)    # 2 # gen_e_imm(bnode, "addq");
expr: O_ADD(imm,expr)    # 2 # gen_imm_eno(bnode, "addq");

expr: O_MUL(expr,expr) # 1 # gen_e_eno(bnode, "imulq");
expr: O_MUL(expr,imm)    # 1 # gen_e_imm(bnode, "imulq");
expr: O_MUL(imm,expr)  # 1 # gen_imm_eno(bnode, "imulq");

expr: O_OR(expr,expr) # 1 # gen_e_eno(bnode, "orq");
expr: O_OR(expr,imm)    # 2 # gen_e_imm(bnode, "orq");

expr: O_LESS(expr,expr) # 3 # gen_eqless(bnode, "l", 1, 1);
expr: O_LESS(expr,imm)  # 3 # gen_eqless(bnode, "l", 1, 0);
expr: O_LESS(imm,expr)  # 3 # gen_eqless(bnode, "l", 0, 1);

expr: O_EQ(expr,expr) # 3 # gen_eqless(bnode, "e", 1, 1);
expr: O_EQ(expr,imm)    # 3 # gen_eqless(bnode, "e", 1, 0);
expr: O_EQ(imm,expr)    # 3 # gen_eqless(bnode, "e", 0, 1);
expr: O_EQ(nexpr,O_NULL)  # 0 #
expr: O_EQ(expr,O_NULL) # 3 # gen_eqless(bnode, "e", 1, 0);

expr: O_FIELD(expr) # 1 # printf("\t//field(expr)\n"); KIDREG2PARM(0); printf("\tmovq %d(%%%s), %%%s\n", bnode->soffset * 8, KID_REG(0), BN_REG);
expr: O_FIELD(imm) # 1 # printf("\t//field(imm)\n"); printf("\tmovq %d, %%%s\n", KID_VAL(0) + (bnode->soffset * 8), BN_REG);


nexpr: O_EQ(expr,O_NULL) # 0 # gen_eqless(bnode, "ne", 1, 0);


imm: O_ADD(imm,imm)  # 0 # BN_VAL = KID_VAL(0) + KID_VAL(1);
imm: O_SUB(imm,imm)  # 0 # BN_VAL = KID_VAL(0) - KID_VAL(1);
imm: O_MUL(imm,imm)  # 0 # BN_VAL = KID_VAL(0) * KID_VAL(1);
imm: O_LESS(imm,imm) # 0 # BN_VAL = KID_VAL(0) < KID_VAL(1) ? 1 : 0;
imm: O_EQ(imm,imm)   # 0 # BN_VAL = KID_VAL(0) = KID_VAL(1) ? 1 : 0;
imm: O_NUM # 0 #

%%

/* vim: filetype=c
 */