/* Micro-C Code Generatation Part for intel386 */

#define EXTERN extern
#include "mc.h"

#define REGISTERS6   0

void code_init(void);
void free_register(int i);
void emit_init(void);
void emit_push(void);
void gexpr(int e1);
void g_expr(int e1);
void bexpr(int e1, char cond, int l1);
void b_expr(int e1, char cond, int l1);
void string(int e1);
void function(int e1);
void machinop(int e1);
void rindirect(int e1);
void assign(int e1);
void sassign(int e1);
void assop(int e1);
void tosop(int op);
char *div_setup(int oreg) ;
void shift(char *op, int reg) ;
void ld_indexx(int byte, int n, char *xrn);
void st_indexx(int byte, int n, char *xrn);
void indexy(char *op, char *gvar);
void cmpdimm(int e, int csreg);
void global_table(void) ;
void local_table(void) ;
void opening(char *filename);
void closing(void);
void gen_gdecl(char *n, int gpc) ;
void jmp_label(int l);
void jmp_eq_label(int l);
void rexpr(int e1, int l1, char *s);
void jcond(int l, char cond);
void jmp(int l);
void def_label(int cslabel, int dlabel) ;
void gen_comment(char *s);
void gen_source(char *s);
void code_enter(char *name) ;
void code_leave(char *name) ;
void enter(char *name) ;
void enter1(int disp) ;
void ret(void);
void emit_data(int e, int t, NMTBL *n);
void    text_mode(void);
void    data_mode(char *name);
int  get_register_var(void);
void	jump(int e1, int env);
int	lvar(int l);

int cadr(int e);
int car(int e);
int caddr(int e);
int fwdlabel(void);
void fwddef(int l);
int cadddr(int e);
int backdef(void);
int error(int n);
int size(int t);
int list3(int e1, int e2, int e3);

#define TEXT_EMIT_MODE 0
#define DATA_EMIT_MODE 1
#define RODATA_EMIT_MODE 2

static output_mode = TEXT_EMIT_MODE;
static data_alignment = 0;

/*
         local1 <----24 local variable
        %esi        -20  <- disp_offset
        %edi        -16
        %edx        -12
        %ecx         -8
        %ebx         -4
        %ebp = %esp   0
        %eip          4   <- arg_offset
          arg1        8
            see enter/enter1/leave
 */
int arg_offset = 8;
int disp_offset = -20;
int func_disp_offset = -20;
int code_disp_offset = 0;
int int_size = 4;
int endian = 0;
int MAX_REGISTER=6;         /* intel386のレジスタを4つまで使う*/
int REAL_MAX_REGISTER=8;    /* intel386のレジスタが8つということ*/
int MAX_DATA_REG=4;    
int MAX_POINTER=3;    
int MAX_REGISTGER_VAR=2;    

static int  creg;     /* current register */
static char *crn;     /* current register name */
static int  lreg;     /* operand register */
static char *lrn;     /* operand register name */
static int  dreg;     /* temporary register */
static char *drn;     /* temporary register name */
static int  xreg;     /* pointer register */
static int  reg_sp;   /* REGister Stack-Pointer */


#define REG_EAX   0
#define REG_EBX   1
#define REG_ECX   2
#define REG_EDX   3
#define REG_ESI   4
#define REG_EDI   5
#define REG_EBP   6
#define REG_ESP   7


#define DATA_REG 0    
#define POINTER_REG 3    
static char *reg_name[8]; 
static char *reg_name_l[4];

/*
    creg   currrent virtual register
    lreg   operand virtual register
    dreg   spare virtual register

    rname[creg]   currrent real register
    rname[lreg]   operand real register
    rname[dreg]   spare real register

    regs[]        virtual register usage

    reg_name[rname[creg]]
 */

#define MAX_MAX 10
static int rname[MAX_MAX];
static int regs[MAX_MAX];       /* 使われているレジスタを示すフラグ */
static int reg_stack[MAX_MAX];  /* 実際のレジスタの領域 */

void
code_init(void)
{
    if (REGISTERS6) {
	arg_offset = 8;
	func_disp_offset = -20;
	int_size = 4;
	endian = 0;
	MAX_REGISTER=6;
	MAX_DATA_REG=4;    
	MAX_POINTER=3;    
    } else {
	arg_offset = 8;
	func_disp_offset = -12;
	int_size = 4;
	endian = 0;
	MAX_REGISTER=4;
	MAX_DATA_REG=4;    
	MAX_POINTER=1;    
    }
    MAX_REGISTER_VAR=2;    

    reg_name[REG_EAX] = "%eax";
    reg_name[REG_EBX] = "%ebx";
    reg_name[REG_ECX] = "%ecx";
    reg_name[REG_EDX] = "%edx";
    reg_name[REG_ESI] = "%esi";
    reg_name[REG_EDI] = "%edi";
    reg_name[REG_EBP] = "%ebp";
    reg_name[REG_ESP] = "%esp";
    reg_name_l[REG_EAX] = "%al";
    reg_name_l[REG_EBX] = "%bl";
    reg_name_l[REG_ECX] = "%cl";
    reg_name_l[REG_EDX] = "%dl";

}

char *
register_name(int i)
{
    return reg_name[rname[i]];
}

int 
get_register(void)
{    /* 使われていないレジスタを調べる */
    int i;
    for(i=0;i<MAX_REGISTER;i++) {
	if (! regs[i]) {    /* 使われていないなら */
	    regs[i]=1;      /* そのレジスタを使うことを宣言し */
	    return i;       /* その場所を表す番号を返す */
	}
    }
    return -1;    /* 空いている場所がないなら、それを表す -1 を返す */
}

void 
free_register(int i) {    /* いらなくなったレジスタを開放 */
    regs[i]=0;
}

int
register_full(void)
{
    int i;
    for(i=0;i<MAX_REGISTER;i++) {
	if (! regs[i]) { 
	    return 0;  
	}
    }
    return 1;    
}

void 
gexpr_init(void)
{
    int i;
    while(reg_sp > 0) {
	free_register(reg_stack[--reg_sp]);
    }
    text_mode();
}

void 
emit_init(void)
{
    int i;
    for(i=0;i<REAL_MAX_REGISTER;i++) regs[i]=0;
    for(i=0;i<REAL_MAX_REGISTER;i++) rname[i]=i;
    creg = get_register();
    crn = reg_name[rname[creg]];
    dreg = get_register();
    drn = reg_name[rname[dreg]];
    reg_sp = 0;
    text_mode();
}

void 
set_crn(int i)
{
    creg = i;
    crn = reg_name[rname[creg]];
}

void 
set_drn(int i)
{
    dreg = i;
    drn = reg_name[rname[dreg]];
}

int
virtual(int real)
{
    int real_v,i;
    real_v = -1;
    for(i=0;i<MAX_REGISTER;i++) {
	if (rname[i]==real) {
	    real_v=i;
	    break;
	}
    }
    if (real_v == -1)
	error(-1);
    return real_v;
}

void 
use_register(int virt, int real, int move)
{
    int real_v;
    char *move_op;
    if (rname[virt]==real)
	return;
    real_v = virtual(real);
    move_op = regs[real_v]?"\txchg %s,%s\n":"\tmovl %s,%s\n";
    if (move || regs[real_v]) {
	printf(move_op,reg_name[rname[virt]],reg_name[real]);
    } 
    rname[real_v] = rname[virt];
    rname[virt] = real; 
    crn = reg_name[rname[creg]];
    drn = reg_name[rname[dreg]];
    lrn = reg_name[rname[lreg]];
}

void 
use_pointer(int virt, int move)
{
    int i;
    if (rname[virt]>=POINTER_REG)
	return;
    for(i=POINTER_REG;i<MAX_REGISTER;i++) {
	if (!regs[virtual(i)]) {
	    use_register(virt,i,move);
	    return;
	}
    }
    /* we prefer EBX */
    use_register(virt,REG_EBX,move);
}

void 
use_data_reg(int virt, int move)
{
    int i;
    if (rname[virt]<MAX_DATA_REG)
	return;
    for(i=0;i<MAX_DATA_REG;i++) {
	if (!regs[virtual(i)]) {
	    use_register(virt,i,move);
	    return;
	}
    }
    /* we prefer EBX */
    use_register(virt,REG_EBX,move);
}

int 
pop_register(void)
{     /* レジスタから値を取り出す */
    int i,j;

    j = creg;
    i = reg_stack[--reg_sp];

    if(i<0) {
	return i;
    } else {
	free_register(i);
	lreg = i;
	lrn = reg_name[rname[lreg]];
	regs[i]=0;
	return lreg;
    }
}

int
stack_used(void) {
    return reg_stack[--reg_sp]<0;
}

void 
emit_push(void)
{
    int new_reg;
    new_reg = get_register();
    if(new_reg<0) {                     /* もうレジスタがない */
	reg_stack[reg_sp++] =  -1;
	printf("\tpushl %s\n",crn);
    } else {
	reg_stack[reg_sp++] = creg;     /* push するかわりにレジスタを使う */
	set_crn(new_reg);
    }
}

char *
emit_pop(int type)
{
    char *xrn;
    if (pop_register()==-1) {
	if (type==POINTER_REG)
	    use_pointer(dreg,0);
	else if (type==DATA_REG)
	    use_data_reg(dreg,0);
	printf("\tpopl %s\n",drn);
	xrn = drn;
	xreg = dreg;
    } else {
	xrn = lrn;
	xreg = lreg;
    }
    return xrn;
}

int
get_register_var(void)
{
    int i;
    for(i=REG_ESI;i<REG_ESP;i++) {
	if (! regs[i]) {    /* 使われていないなら */
	    regs[i]=1;      /* そのレジスタを使うことを宣言し */
	    return i;       /* その場所を表す番号を返す */
	}
    }
    return -1;
}

void
gexpr(int e1)
{
    gexpr_init();
    g_expr(e1);
    csvalue = rname[creg]; /* for siwtch value */
}

void
g_expr(int e1)
{
    int e2,e3,e4;
    char *xrn;
    NMTBL *n;

    if (chk) return;
    e2 = cadr(e1);
    switch (car(e1)){
    case GVAR:   
	/* use_pointer(creg,0); */
	printf("\tmovl $%s,%s\n",caddr(e1),crn);
	return;
    case RGVAR:
	/* use_pointer(creg,0); */
	printf("\tmovl %s,%s\n",caddr(e1),crn);
	return;
    case CRGVAR:
	printf("\tmovsbl %s,%s\n",caddr(e1),crn);
	return;
    case LVAR:
	/* use_pointer(creg,0); */
	printf("\tlea %d(%%ebp),%s\n",lvar(e2),crn);
	return;
    case REGISTER:
	/* this is of course redundant... */
	printf("\tmovl %s,%s\n",register_name(e2),crn);
	return;
    case RLVAR:
	printf("\tmovl %d(%%ebp),%s\n",lvar(e2),crn);
	return;
    case CRLVAR:
	printf("\tmovsbl %d(%%ebp),%s\n",lvar(e2),crn);
	return;
    case FNAME:
	printf("\tmovl $%s,%s\n",((NMTBL *)e2)->nm,crn);
	return;
    case CONST:  /* 代入する値が0でも特別な処理はしない */
	printf("\tmovl $%d,%s\n",e2,crn);
	return;
    case STRING:
	string(e1);
	return;
    case FUNCTION:
	function(e1);
	return;
    case CODE:
	jump(e2,caddr(e1));
	return;
    case INDIRECT:
	g_expr(e2);
	return;
    case RINDIRECT: case CRINDIRECT:
	rindirect(e1);
	return;
    case ADDRESS:
	g_expr(e2);
	return;
    case MINUS:  /* レジスタに対し、neglを実行すれば実現可能 */
	g_expr(e2);
	/* use_data_reg(creg,1); */
	printf("\tnegl %s\n", crn);
	return;
    case BNOT:   /* ~ */
	g_expr(e2);
	/* use_data_reg(creg,1); */
	printf("\tnotl %s\n", crn);
	return;
    case LNOT:   /* !  */
	g_expr(e2);
	use_data_reg(creg,1);
	printf("\tcmpl $0,%s\n", crn);
	printf("\tsete %s\n", reg_name_l[rname[creg]]);
	printf("\tmovzbl %s,%s\n", reg_name_l[rname[creg]],crn);
	return;
    case PREINC:
	if (car(e2)==REGISTER) {
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2)));
	    printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	    return;
	} 
	g_expr(e2);
	printf("\taddl $%d,(%s)\n",caddr(e1),crn);
	printf("\tmovl (%s),%s\n",crn,crn);
	return;
    case POSTINC:
	if (car(e2)==REGISTER) {
	    printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2)));
	    return;
	} 
	g_expr(e2);
	emit_push();  
/* in case of register full we should copy crn to drn */
	xrn = emit_pop(0);
	printf("\tmovl (%s),%s\n",xrn,crn);
	printf("\taddl $%d,(%s)\n",caddr(e1),xrn);
	return;
    case CPOSTINC:
	/*   char *p; *p++ */
	if (car(e2)==REGISTER) {
	    printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2)));
	    return;
	} 
	g_expr(e2);
	emit_push(); /* in case of register full we should copy crn to drn */
	xrn = emit_pop(0);
	printf("\tmovsbl (%s),%s\n",xrn,crn);
	printf("\tincl (%s)\n",xrn);
	return;
    case CPREINC:
	if (car(e2)==REGISTER) {
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2)));
	    printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	    return;
	} 
	g_expr(e2);
	printf("\tincl (%s)\n",crn);
	printf("\tmovsbl (%s),%s\n",crn,crn);
	return;
    case CPOSTDEC:
	if (car(e2)==REGISTER) {
	    printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	    printf("\tdecl %s\n",register_name(cadr(e2)));
	    return;
	} 
	g_expr(e2);
	printf("\tmovsbl (%s),%s\n",crn,crn);
	printf("\tdecl (%s)\n",crn);
	return;
    case CPREDEC:
	if (car(e2)==REGISTER) {
	    printf("\tdecl %s\n",register_name(cadr(e2)));
	    printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	    return;
	} 
	g_expr(e2);
	emit_push();
	xrn = emit_pop(0);
	printf("\tdecl (%s)\n",xrn);
	printf("\tmovsbl (%s),%s\n",xrn,crn);
	return;
    case MUL: case UMUL:
    case DIV: case UDIV:	   
    case MOD: case UMOD:
    case LSHIFT: case ULSHIFT: case RSHIFT: case URSHIFT:
    case ADD: case SUB: case BAND: case EOR: case BOR:
	machinop(e1);
	return;
    case COND:
	e2=fwdlabel();
	b_expr(cadr(e1),0,e2);
	g_expr(caddr(e1));
	e4 = rname[creg];
	jmp(e3=fwdlabel());
	fwddef(e2);
	g_expr(cadddr(e1));
	use_register(creg,e4,1);
	fwddef(e3);
	return;
    case SASS: 
	sassign(e1);
	return;
    case ASS: case CASS:
	assign(e1);
	return;
    case ASSOP: case CASSOP:
	assop(e1);
	return;
    case COMMA:
	g_expr(e2);
	g_expr(caddr(e1));
	return;
    case RETURN:
	n = (NMTBL *)e2;
	if (retcont==0)
	    retcont=fwdlabel();
	printf("\tleal _%d,%s\n",retcont,crn);
	return;
    case ENVIRONMENT:
	printf("\tmovl %%ebp,%s\n",crn);
	return;
    default:
	b_expr(e1,1,e2=fwdlabel());  /* including > < ... */
	printf("\txorl %s,%s\n",crn,crn);
	jmp(e3=fwdlabel());
	fwddef(e2);
	printf("\tmovl $1,%s\n",crn);
	fwddef(e3);
    }
}

void
bexpr(int e1, char cond, int l1)
{
    gexpr_init();
    b_expr(e1,cond,l1);
}

void
b_expr(int e1, char cond, int l1)
{
    int e2,l2;
    if (chk) return;
    e2=cadr(e1);
    switch(car(e1)) {
    case LNOT:
	b_expr(e2,!cond,l1);
	return;
    case GT:
	rexpr(e1,l1,cond?"g":"le");
	return;
    case UGT:
	rexpr(e1,l1,cond?"a":"be");
	return;
    case GE:
	rexpr(e1,l1,cond?"ge":"l");
	return;
    case UGE:
	rexpr(e1,l1,cond?"ae":"b");
	return;
    case LT:
	rexpr(e1,l1,cond?"l":"ge");
	return;
    case ULT:
	rexpr(e1,l1,cond?"b":"ae");
	return;
    case LE:
	rexpr(e1,l1,cond?"le":"g");
	return;
    case ULE:
	rexpr(e1,l1,cond?"be":"a");
	return;
    case EQ:
	rexpr(e1,l1,cond?"e":"ne");
	return;
    case NEQ:
	rexpr(e1,l1,cond?"ne":"e");
	return;
    case LAND:
	b_expr(e2,0,cond?(l2=fwdlabel()):l1);
	b_expr(caddr(e1),cond,l1);
	if(cond) fwddef(l2);
	return;
    case LOR:
	b_expr(e2,1,cond?l1:(l2=fwdlabel()));
	b_expr(caddr(e1),cond,l1);
	if(!cond) fwddef(l2);
	return;
    case CRGVAR:
	printf("\tcmpb $0,%s\n",caddr(e1));
	jcond(l1,cond);
	return;
    case CRLVAR:
	printf("\tcmpb $0,%d(%%ebp)\n",lvar(e2));
	jcond(l1,cond);
	return;
    case RGVAR:
	printf("\tcmpl $0,%s\n",caddr(e1));
	jcond(l1,cond);
	return;
    case RLVAR:
	printf("\tcmpl $0,%d(%%ebp)\n",lvar(e2));
	jcond(l1,cond);
	return;
    case REGISTER:
	printf("\tcmpl $0,%s\n",register_name(e2));
	jcond(l1,cond);
	return;
    case CONST:
	if((cond&&e2)||(!cond&&!e2)) jmp(l1);
	return;
    default:
	g_expr(e1);
	printf("\tcmpl $0,%s\n",crn);
	jcond(l1,cond);
	return;
    }
}

void
ascii(char *s)
{
    printf("\t.string \"");
    while(*s) {
	if (*s=='\n')
	    printf("%cn",92);
	else if (*s<' ')
	    printf("%c%03o",92,*s);
	else if (*s==34)
	    printf("%c%c",92,34);
	else 
	    printf("%c",*s);
	s++;
    }
    printf("%c\n",34);
}

void
string(int e1)
{
    char *s;
    int i,lb;

    if (0) {
	s=(char *)cadr(e1);
	lb=fwdlabel();
	printf("\tjmp _%d\n",lb);
	i=backdef();
	ascii(s);
	printf("\t.align 2\n");
	fwddef(lb);
	printf("\tlea _%d,%s\n",i,crn);
    } else {
	s=(char *)cadr(e1);
	printf(".section\t.rodata\n");
	lb=fwdlabel();
	printf("_%d:\n",lb);
	ascii(s);
	if (output_mode==TEXT_EMIT_MODE) {
	    printf(".text\n");
	} else {
	    text_mode();
	}
	printf("\tlea _%d,%s\n",lb,crn);
    }
}

void
function(int e1)
{
    int e2,e3,e4,e5,nargs;
    NMTBL *n;

    e2 = cadr(e1);
    nargs = 0;
    for (e3 = caddr(e1); e3; e3 = cadr(e3)) {	
	n=(NMTBL *)(e5=(cadr(e4 = car(e3))));
	switch(car(e4)) {
	case FNAME:
	    printf("\tlea %s,%s\n",n->nm,crn);
	    printf("\tpushl %s\n",crn);
	    break;
	case ADDRESS:
	    g_expr(e5);
	    printf("\tpushl %s\n",crn);
	    break;
	default:g_expr(e4);
	    printf("\tpushl %s\n",crn);
	}
	++nargs;
    }
    if (car(e2) == FNAME) {	
	n=(NMTBL *)cadr(e2);
	use_register(creg,REG_EAX,0);
	printf("\tcall\t%s\n",n->nm);
    } else {	
	g_expr(e2);
	use_register(creg,REG_EAX,0);
	printf("\tcall\t*%s\n",crn);
    }
    if (nargs) printf("\taddl $%d,%%esp\n",4*nargs);
}

void
jump(int e1, int env)
{
    int i,e2,e3,e4,e5,nargs,regs;
    NMTBL *n,*code0;
    int new_disp;
    char *xrn;

    /* count number of args */
    nargs = 0;
    for (e3 = caddr(e1); e3;e3 =cadr(e3)) nargs++;
    new_disp = -(nargs-MAX_REGISTER_VAR)*int_size;
    if (new_disp > 0)
	new_disp=0;
/* printf("# new_disp %d,disp %d\n",new_disp,disp); */
    if (new_disp < disp) {
	printf("\tlea %d(%%ebp),%%esp\n",new_disp+disp_offset);
    }
    /* compute jump address */
    e2 = cadr(e1);
    if (car(e2) == FNAME) {	
	code0=(NMTBL *)cadr(e2);
	if (code0->sc!=CODE) {
	    error(STERR); return;
	}
    } else {	/* indirect */
	g_expr(e2);
	emit_push();
    }
    /* compute arguments */
    regs = nargs-1;
    i=0;
    for (e3 = caddr(e1); e3;e3 =cadr(e3),i++) {
	n=(NMTBL *)(e5=(cadr(e4 = car(e3))));
	switch(car(e4)) {
	case FNAME:
	    printf("\tlea %s,%s\n",n->nm,crn);
	    emit_push();
	    break;
	case ADDRESS:
	    g_expr(e5);
	    emit_push();
	    break;
/*
printf("# cadr(e4) %d ==disp_offset+(-1-i)*int_size %d\n", cadr(e4), disp_offset+(-2-i)*int_size);
 */
	case RLVAR:
	case CRLVAR:
	    if (env==0 && cadr(e4)==disp_offset+(-1-i)*int_size) {
		/* Same positioned local variable. No need to copy */
		reg_stack[reg_sp++] = -2;
		--regs;
		continue;
	    }
	case REGISTER:
	    if (rname[cadr(e4)]==REG_ESI+regs) {
		/* Same register variable. No need to copy */
		reg_stack[reg_sp++] = cadr(e4);
		--regs;
		continue;
	    }
	default:
	    g_expr(e4);
	    emit_push();
	}
	--regs;
    }
    /* save frame pointer before jump in fuction */
    if (fnptr->sc==FUNCTION) {
	printf("\tmovl %%ebp,%d(%%ebp)\n",disp_offset);
    } 
    if (env) {
	/* change frame pointer */
	g_expr(env);
	printf("\tmovl %s,%%ebp\n",crn);
    }
    /* copy arguments to destination environment if necessary */
    for(i=0;i<nargs;i++) {
    	if (i>=MAX_REGISTGER_VAR) {
	    if (reg_stack[reg_sp-1]== -2) {
		/* same positioned variable */
		reg_sp--;
	    } else {
		xrn=emit_pop(0);
		printf("\tmovl %s,%d(%%ebp)\n",xrn, 
		    disp_offset+(-(nargs-i))*int_size);
	    }
	} else if (reg_stack[--reg_sp]>=REG_ESI) {
	    /* the same registger */
	    ;
	} else {
	    if(reg_stack[reg_sp]<0) {
		printf("\tpopl %s\n",reg_name[rname[REG_ESI+i]]);
	    } else {
		printf("\tmovl %s,%s\n",
			reg_name[rname[reg_stack[reg_sp]]],
			reg_name[rname[REG_ESI+i]]);
		free_register(reg_stack[reg_sp]);
	    }
	}
    }
    if (car(e2) != FNAME) {	
	xrn=emit_pop(0);
    }
/* printf("# new_disp %d,disp %d\n",new_disp,disp); */
    if (new_disp>disp) {
	/* shrink stack if necessary */
	printf("\tlea %d(%%ebp),%%esp\n",new_disp+disp_offset);
    } 
    if (fnptr->sc==FUNCTION) {
	/* link operation for leave, %ebp must point saved old %ebp */
	printf("\tlea %d(%%ebp),%%ebp\n",disp_offset);
    } 
    if (car(e2) == FNAME) {	
	printf("\tjmp %s\n",code0->nm);
    } else {
	printf("\tjmp *%s\n",xrn);
    }
}


void
machinop(int e1)
{
    int e2,e3,op;

    e2 = cadr(e1);
    op = car(e1);
    e3 = caddr(e1);
    g_expr(e3);
    emit_push();
    g_expr(e2);
    tosop(car(e1));
    return;
}


void
rindirect(int e1)   /* *(p +5 ) */
       
{
    char *op;
    int e2,e3,byte;

    op = ((byte = (car(e1) == CRINDIRECT)) ? "movsbl" : "movl");
    e3 = cadr(e2 = cadr(e1));
    g_expr(e2);
    printf("\t%s (%s),%s\n",op,crn,crn);
}

void
sassign(int e1)
{
    int e2,e3,e4,sz;
    char *xrn;

    e2 = cadr(e1);
    e3 = cadr(e2);
    e4 = caddr(e1);
    sz = size(cadr(e2));  /* cld rep movsb */
    g_expr(e4);
    emit_push();
    g_expr(e2);
    xrn = emit_pop(0);
    return;
}

void
assign(int e1)
{
    char *op;
    int e2,e3,e4,byte;
    char *xrn;

    op = ((byte=(car(e1) == CASS))? "movb" : "movl");
    /*    e2=e4 */
    e2 = cadr(e1);
    e3 = cadr(e2);
    e4 = caddr(e1);
    switch(car(e2)) {
    case GVAR:      /*   i=3 */
            g_expr(e4);
            if (byte) use_data_reg(creg,1);
            printf("\t%s %s,%s\n",op,crn,caddr(e2));
            return;
    case LVAR:
            g_expr(e4);
            if (byte) use_data_reg(creg,1);
            printf("\t%s %s,%d(%%ebp)\n",op,crn,lvar(cadr(e2)));
            return;
    case REGISTER:
            g_expr(e4);
	    if (creg!=cadr(e2))
		printf("\t%s %s,%s\n",op,crn,register_name(cadr(e2)));
            return;
    }
    g_expr(e4);
    emit_push();
    g_expr(e2);
    xrn = emit_pop(0);
    if (byte) use_data_reg(creg,1);
    printf("\t%s %s,(%s)\n",op,xrn,crn);
    printf("\tmovl %s,%s\n",xrn,crn);
    return;
}

void
assop(int e1)
{
    int e2,e3,byte,op,new_reg;
    char *xrn;

    /*   e2 op= e3 */
    byte = (car(e1) == CASSOP);
    e2 = cadr(e1);
    if (car(e2)==INDIRECT) e2=cadr(e2);
    e3 = caddr(e1);
    op = cadddr(e1);

    g_expr(e3);
    emit_push();
    if (car(e2)==REGISTER) {
	new_reg=creg;
	set_crn(cadr(e2));
	tosop(op);
	set_crn(new_reg);
	printf("\tmovl %s,%s\n",register_name(cadr(e2)),crn);
	return;
    }
    g_expr(e2);
    xrn = emit_pop(0);                           /* pop e3 value */
    printf("\tpushl %s   # assop \n",crn);      /* push e2 address */
    ld_indexx(byte,0,crn);
    new_reg = get_register();
    /* push e3 value */
    if(new_reg<0) {                     /* もうレジスタがない */
        reg_stack[reg_sp++] =  -1;
        printf("\tpushl %s\n",xrn);
    } else {
        reg_stack[reg_sp++] = xreg;     /* push するかわりにレジスタを使う */
    }
    tosop(op);
    if(new_reg>=0) free_register(new_reg);
    printf("\tpopl %s   # assop \n",drn);
    printf("\t%s %s,(%s)\n",byte ? "movb" : "movl",crn,drn);
    return;

}


void
tosop(int op)
{
    int oreg;
    char *orn;

    oreg = pop_register();
    switch(op) {
    case LSHIFT:
    case ULSHIFT:
	shift("sall",oreg);
	return;
    case RSHIFT:
	shift("sarl",oreg);
	return;
    case URSHIFT:
	shift("shrl",oreg);
	return;
    }
    if(oreg==-1) {
        printf("\tpopl %s\n",drn);
	oreg = dreg;
    }
    orn = reg_name[rname[oreg]];
    switch(op) {
    case ADD:
	printf("\taddl %s,%s\n",orn,crn);
	return;
    case SUB:
	printf("\tsubl %s,%s\n",orn,crn);
	return;
    case BAND: 
	printf("\tandl %s,%s\n",orn,crn);
	return;
    case EOR: 
	printf("\txorl %s,%s\n",orn,crn);
	return;
    case BOR:
	printf("\torl %s,%s\n",orn,crn);
	return;
    case MUL:
    case UMUL:
	/* use_register(dreg,REG_EDX,0); */
	printf("\t%s %s,%s\n","imull",orn,crn);
	return;
    case DIV:
    case UDIV:
	orn = div_setup(oreg);
	if (op==DIV)
	    printf("\tcltd\n\tdivl %s\n",orn);
	else 
	    printf("\txor %%edx,%%edx\n\tidivl %s\n",orn);
	div_cleanup(orn);
	return;
    case MOD:
    case UMOD:
	orn = div_setup(oreg);
	if (op==DIV)
	    printf("\tcltd\n\tdivl %s\n",orn);
	else 
	    printf("\txor %%edx,%%edx\n\tidivl %s\n",orn);
	rname[creg]=REG_EDX;
	crn=reg_name[REG_EDX];
	rname[dreg]=REG_EAX;
	drn=reg_name[REG_EAX];
	div_cleanup(orn);
	return;
    }
}

static char *dvi_push = "(%esp)";

char *
div_setup(int oreg)
{
    if (oreg<0) {
	use_register(creg,REG_EAX,1);
	use_register(dreg,REG_EDX,0);
	return 0;
    }
    if (register_full()) {
	printf("\tpushl %s\n",reg_name[rname[oreg]]);
	use_register(creg,REG_EAX,1);
	use_register(oreg,REG_EDX,0);
	return dvi_push;
    }
    regs[oreg]=1;
    use_register(creg,REG_EAX,1);
    use_register(dreg,REG_EDX,0);
    regs[oreg]=0;
    return reg_name[rname[oreg]];
}

div_cleanup(char *orn)
{
    if (orn==dvi_push)
	printf("\taddl $4,%%esp\n");
}

void
shift(char *op, int reg)
{
    if (reg>=0) {
	use_register(lreg,REG_ECX,1);
    } else {
	use_register(dreg,REG_ECX,0);
	printf("\tpopl %%ecx\n");
    }
    printf("\t%s %%cl,%s\n",op,crn);
}

void
ld_indexx(int byte, int n, char *xrn)
{	
    char *op;

    op = byte ? "movsbl" : "movl";
    if (n) 
	    printf("\t%s %d(%s),%s\n",op,n,xrn,crn);
    else
	    printf("\t%s (%s),%s\n",op,xrn,crn);
}

void
st_indexx(int byte, int n, char *xrn)
{	
    char *op;

    op = byte ? "movb" : "movl";
    if (n) 
	    printf("\t%s %s,%d(%s)\n",op,crn,n,xrn);
    else
	    printf("\t%s %s,(%s)\n",op,crn,xrn);
}

void
indexy(char *op, char *gvar)
{
    printf("\t%s %s,%s\n",op,crn,gvar);
}

void
cmpdimm(int e, int csreg)
{
    /* used in dosiwtch() */
    use_register(creg,csreg,0);
    printf("\tcmpl $%d,%s\n",e,crn);
}

void
opening(char *filename)
{
    printf("\t.file \"%s\"\n",filename);
    printf("\t.version\t\"01.01\"\n");
    printf("gcc2_compiled.:\n");
    printf(".text\n");
    emit_init();
}

void
closing(void)
{
    global_table();
    printf("\t.ident \"Micro-C compiled\"\n");
}

void
jmp_label(int l)
{
    printf("\tjmp\t_%d\n",l);
}

void
jmp_eq_label(int l)
{
     printf("\tje\t_%d\n",l);
}

void
rexpr(int e1, int l1, char *s)
{       
    g_expr(list3(SUB,cadr(e1),caddr(e1)));
    printf("\tj%s\t_%d\n",s,l1);
}

void
jcond(int l, char cond)
{       
    printf("\tj%s\t_%d\n",cond?"ne":"e",l);
}

void
jmp(int l)
{       
    control=0;
    printf("\tjmp\t_%d\n",l);
    /* align? */
}

int
fwdlabel(void)
{       
    return labelno++;
}

void
fwddef(int l)
{       
    control=1;
    printf("_%d:\n",l);
}

int
backdef(void)
{       
    control=1;
    printf("_%d:\n",labelno);
    return labelno++;
}

void
def_label(int cslabel, int dlabel)
{
    int fl;

    fl = 0;
    if (control) {
	jmp(fl=fwdlabel());
    }
    fwddef(cslabel);
    if (dlabel)
	jmp(dlabel);
    if (fl) {
	fwddef(fl);
    }
}

void
gen_comment(char *s)
{
     printf("# %s",s);
}

void
gen_source(char *s)
{
     printf("%s",s);
}

void
code_enter(char *name)
{
    disp_offset = code_disp_offset;
    emit_init();
    printf("\t.align 4\n");
    if (stmode!=STATIC)
	printf(".globl %s\n",name);
    printf("\t.type\t%s,@function\n",name);
    printf("%s:\n",name);
}

void
code_enter1(int disp)
{
    if(disp) {
	printf("\tsubl $%d,%%esp\n",-disp);
    }
}

void
code_leave(char *name)
{
    local_table();
    printf("_%d:\n",labelno);
    printf("\t.size\t%s,_%d-%s\n",name,labelno,name);
    labelno++;
}

void
enter(char *name)
{
    disp_offset = func_disp_offset;
    emit_init();
    printf("\t.align 2\n");
    if (stmode!=STATIC)
	printf(".globl %s\n",name);
    printf("%s:\n",name);
    printf("\t.type\t%s,@function\n",name);
    printf("\tpushl %%ebp\n");
    printf("\tmovl %%esp,%%ebp\n");
    printf("\tpushl %%ebx\n");
    printf("\tpushl %%ecx\n");
    printf("\tpushl %%edx\n");
    if (REGISTERS6) {
	printf("\tpushl %%edi\n");
	printf("\tpushl %%esi\n");
    }
}

void
enter1(int disp)
{
    if(disp) printf("\tsubl $%d,%%esp\n",-disp);
}

void
leave(int control, char *name)
{
    if (control)
	use_register(creg,REG_EAX,1);
    if (retcont) {
	if (control)
	    jmp(retlabel);
	fwddef(retcont);
	use_register(creg,REG_EAX,0);
	printf("\tmovl %s,%s\n",reg_name[REG_ESI],crn);
	/* printf("\tleave\n"); */
    }
    fwddef(retlabel);
    use_register(creg,REG_EAX,0);
    if (REGISTERS6) {
	printf("\tpopl %%esi\n");
	printf("\tpopl %%edi\n");
    }
    /* if(disp) printf("\taddl $%d,%%esp\n",-disp);  */
    printf("\tlea %d(%%ebp),%%esp\n",disp_offset);
    printf("\tpopl %%edx\n");
    printf("\tpopl %%ecx\n");
    printf("\tpopl %%ebx\n");
    printf("\tleave\n");
    printf("\tret\n");
    local_table();
    printf("_%d:\n",labelno);
    printf("\t.size\t%s,_%d-%s\n",name,labelno,name);
    labelno++;
}


void
ret(void)
{       
    use_register(creg,REG_EAX,1);
    jmp(retlabel); 
}

void
gen_gdecl(char *n, int gpc)
{
    /*
    if (stmode!=STATIC)
	printf(".globl %s\n",n); 
     */
}

void 
align(int t)
{
    if (t!=CHAR) {
	if (data_alignment & 1)
	    printf("\t.align 2\n");
	data_alignment = 0;
    }
}

void
emit_data(int e, int t, NMTBL *n)
{
    int l;
    char *name;
    name = n->nm; 
    if(mode==GDECL)  { /* global */
	if (n->dsp != -1) {
	    n->dsp = -1;   /* initiallized flag */
	    printf(".globl\t%s\n",name);
	    data_mode(name);
	    align(t);
	    printf("%s:\n",name); 
	} else {
	    data_mode(0);
	}
        if(car(e)==CONST) {       
	    if (t==CHAR) {
		printf("\t.byte %d\n",cadr(e));
		if (data_alignment>0)
		    data_alignment++;
		gpc += 1;
	    } else {
		printf("\t.long %d\n",cadr(e));
		gpc += int_size;
	    }
        } else if(t!=CHAR) {       
	    gpc += int_size;
	    if(car(e)==ADDRESS&&car(cadr(e))==GVAR) {
		printf("\t.long %s\n",caddr(cadr(e)));
	    } else if(car(e)==FNAME) {
		printf("\t.long %s\n",((NMTBL *)cadr(e))->nm);
            } else if(car(e)==STRING) {       
		if (car(n->ty)!=ARRAY || cadr(n->ty)!=CHAR) {
		    l = fwdlabel();
		    printf("\t.long _%d\n",l);
		    printf(".section\t.rodata\n");
		    printf("_%d:\n",l);
		    output_mode = RODATA_EMIT_MODE;
		}
		ascii((char *)cadr(e));
	    } else error(TYERR);
        }
    } else {
	/* if (n->sc!=LVAR) { error(TYERR); return; } */
        if(car(e)==CONST) {       
		printf("\tmovl $%d,%s\n",cadr(e),crn);
		printf("\t%s %s,%d(%%ebp)\n",t==CHAR?"movsbl":"movl",crn,n->dsp);
        } else if(t!=CHAR) {       
		if(car(e)==ADDRESS&&car(cadr(e))==GVAR)
		    printf("\tlea %s,%s\n",caddr(e),crn);
                else if(car(e)==FNAME)
		    printf("\tlea %s,%s\n",((NMTBL *)cadr(e))->nm,crn);
		else if(car(e)==STRING) {       
		    string(e);
                } else error(TYERR);
		printf("\tmovl %s,%d(%%ebp)\n",crn,n->dsp);
        }
    }
}

void
emit_data_closing(NMTBL *n)
{
    int lb;
    if (mode=GDECL) {
	data_mode(0);
	lb=fwdlabel();
	printf("_%d:\n",lb);
	printf("\t.size\t%s,_%d-%s\n",n->nm,lb,n->nm);
    }
}

void
global_table(void)
{
    NMTBL *n;
    for(n=ntable;n < &ntable[GSYMS];n++) {
	if (n->sc == GVAR && n->dsp != -1) {
	    /* n->dsp = -1 means initialized global */
	    printf(".comm %s,%d\n",n->nm,size(n->ty));
	}
    }
}

void
local_table(void)
{
    NMTBL *n;
    /* static local variables */
    for(n=ntable+GSYMS;n < &ntable[GSYMS+LSYMS];n++) {
	if (n->sc == GVAR) {
	    printf(".lcomm %s,%d\n",n->nm,size(n->ty));
	}
    }
}

void
text_mode(void)
{
    if (output_mode!=TEXT_EMIT_MODE) {
	printf(".text\n");
	printf("\t.align 2\n");
	output_mode = TEXT_EMIT_MODE;
    }
}

void
data_mode(char *name)
{
    if (output_mode!=DATA_EMIT_MODE) {
	printf(".data\n");
	output_mode = DATA_EMIT_MODE;
    }
    if (name)
	printf("\t.type\t%s,@object\n",name);
}

int
lvar(int l)
{
    if (l<0) {
	if (fnptr->sc==CODE)
	    return l+code_disp_offset;
	else
	    return l+disp_offset;
    } else {
	return l+arg_offset;
    }
}

/* end */