view mc-nop-386.c @ 413:d4dc6d99ffdb

*** empty log message ***
author kono
date Wed, 20 Oct 2004 00:32:36 +0900
parents 1c2a9232ea93
children
line wrap: on
line source

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

#define EXTERN extern
#include "mc.h"

extern int  get_register_var(void);
extern void bexpr(int e1, char cond, int l1);
extern void closing(void);
extern void cmpdimm(int e, int csreg);
extern void code_enter(char *name) ;
extern void code_enter1(int args);
extern void code_init(void);
extern void code_leave(char *name) ;
extern void leave(int control,char *name) ;
extern void def_label(int cslabel, int dlabel) ;
extern void emit_data(int e, int t, NMTBL *n);
extern void emit_init(void);
extern void enter(char *name) ;
extern void enter1() ;
extern void g_expr(int e1);
extern void gen_comment(char *s);
extern void gen_gdecl(char *n, int gpc) ;
extern void gen_source(char *s);
extern void gexpr(int e1);
extern void jcond(int l, char cond);
extern void jmp(int l);
extern void opening(char *filename);
extern void ret(void);
extern int assign_expr0(int e,int e1,int type,int type1);
extern int integral(int t);
extern void tree_print_t(int e,int t);
extern int rvalue_t(int e,int t);

static int edx_setup() ;
static int	lvar(int l);
static void	jump(int e1, int env);
static void    data_mode(char *name);
static void    text_mode(void);
static void assign(int e1);
static void assop(int e1);
static void b_expr(int e1, char cond, int l1,int err);
static void emit_push(void);
static void free_register(int i);
static void function(int e1);
static void global_table(void) ;
/* static void indexy(char *op, char *gvar); */
/* static void jmp_eq_label(int l); */
/* static void jmp_label(int l); */
static void ld_indexx(int byte, int n, int xreg);
static void local_table(void) ;
static void machinop(int e1);
static void rexpr(int e1, int l1, char *s);
static void rindirect(int e1);
static void sassign(int e1);
static void shift(char *op, int xreg) ;
/* static void st_indexx(int byte, int n, int xreg); */
static void string(int e1);
static void tosop(int op,int reg);
static void edx_cleanup();
static void use_register(int virt, int real, int move);
static void emit_copy(int from,int to,int length,int offset,int value,int det);
static int is_same_type(int s,int t);

extern void error(int n);
extern int fwdlabel(void);
extern void fwddef(int l);
extern int backdef(void);
extern int size(int t);
extern int list4(int e1, int e2, int e3,int e4);
extern int list3(int e1, int e2, int e3);
extern int list2(int e1, int e2);
extern int scalar(int);
extern int reverse0(int);
extern void remove0(int *list,int element); 
extern int append4(int target,int t,int ty,int e1);

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

static int output_mode = TEXT_EMIT_MODE;
static int data_alignment = 0;

static int code_disp_label;
static int func_disp_label;

/*
                                           -16  -8 local2
                                           -12  -4 local1
                                            -8  8  arg3
                                            -4  4  arg2
                                             0  0  arg1
         local2     -20 4                    0    (%edi)
         local1 <-- -16 0 local variable     0    (%esi)
        %edi        -12  <- disp_offset          %ebp
        %esi         -8
        %ebx         -4
        %ebp = %esp   0
        %eip          4   <- arg_offset
          arg1        8 0
          arg2       12 4
            see enter/enter1/leave           see code_enter
 */
int arg_offset = 8;
int disp_offset = -12;
int func_disp_offset = -12;
int code_disp_offset = 0;
int jump_offset = 0;

int size_of_int = 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 int  dreg;     /* temporary 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];
static char *reg_name_w[4];

/*
    creg   currrent virtual register
    dreg   spare virtual register

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

    regs[]        virtual register usage
    regv[]        value in virtual register flag

    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 */
static int regv[MAX_MAX];       /* 値が入っているかどうか */

void
code_init(void)
{
    arg_offset = 8;
    func_disp_offset = -12;
    disp_offset = -12;
    size_of_int = 4;
    endian = 0;
    MAX_REGISTER=6;
    MAX_DATA_REG=4;    
    MAX_POINTER=3;    
    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";
    reg_name_w[REG_EAX] = "%ax";
    reg_name_w[REG_EBX] = "%bx";
    reg_name_w[REG_ECX] = "%cx";
    reg_name_w[REG_EDX] = "%dx";

}

char *
register_name(int i,int byte)
{
    if (i<0) {
	error(REG_ERR);
	return "%eax";
    }
    if (byte && rname[i] <= REG_EDX) {
	return reg_name_l[rname[i]];
    } else {
	return reg_name[rname[i]]; /* should be error */
    }
}

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 */
    regv[i]=regs[i]=0;
}

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

static
int
free_register_count(void)
{
    int i,count;
    count = 0;
    for(i=0;i<MAX_REGISTER;i++) {
	if (! regs[i] && ! regv[i]) count++;
    }
    return count;    
}

static void
free_all_register(void)
{
    int i;
    for(i=0;i<MAX_REGISTER;i++) {
	regs[i]=regv[i]=0;
    }
    creg = get_register();
    dreg = get_register();
    return;
}

void
use_register_var(int i) {
    regv[i]=1;
}

static int creg_regvar = -1;
static int creg_regvar_back;
static int creg_back;

void
creg_destroy() {
    creg_back = creg; creg_regvar_back = creg_regvar;
    if (creg_regvar>=0)
	creg = creg_regvar;
    creg_regvar=-1;
}

void
creg_un_destroy() {
    creg = creg_back; creg_regvar = creg_regvar_back;
}

void
register_usage(char *s)
{
    int i;
    printf("# %d: %s:",lineno,s);
    printf(" creg=%s dreg=%s ",register_name(creg,0),register_name(dreg,0));
    for(i=0;i<MAX_REGISTER;i++) {
	printf("%d",regs[i]);
    }
    printf(":");
    for(i=0;i<MAX_REGISTER;i++) {
	printf("%d",regv[i]);
    }
#if 0
    printf(" regs_stack",register_name(creg,0),register_name(dreg,0));
    for(i=reg_sp;i>=0;i--) {
	if(reg_stack[i]>=0)
	    printf(" %s",register_name(reg_stack[i],0));
    }
#endif
    printf("\n");
}

void 
gexpr_init(void)
{
    while(reg_sp > 0) {
	free_register(reg_stack[--reg_sp]);
    }
    text_mode();
    use_register(creg,REG_EAX,0);
    regv[dreg]=0;
    creg_regvar = -1;
    register_usage("gexpr_init");
}


void 
emit_init(void)
{
    int i;
    for(i=0;i<REAL_MAX_REGISTER;i++) { regs[i]=0; regv[i]=0;rname[i]=i;}
    free_all_register();
    reg_sp = 0;
    text_mode();
}

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 || (regv[real_v])) {
	printf(move_op,reg_name[rname[virt]],reg_name[real]);
    } 
    rname[real_v] = rname[virt];
    rname[virt] = real; 
}

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 */
    return reg_stack[--reg_sp];
}

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",register_name(creg,0));
	/* creg is used soon, don't regv[creg]=0 */
    } else {
	reg_stack[reg_sp++] = creg;     /* push するかわりにレジスタを使う */
	creg = new_reg;
	regv[creg]=1;
    }
}

void 
emit_push_x(int xreg)
{
    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",register_name(xreg,0));
	/* creg is used soon, don't regv[xreg]=0 */
    } else {
	reg_stack[reg_sp++] = xreg;     /* push するかわりにレジスタを使う */
	xreg = new_reg;
	regv[xreg]=1;
    }
}

int
emit_pop(int type)
{
    int xreg;
    if ((xreg=pop_register())==-1) {
	if (type==POINTER_REG)
	    use_pointer(dreg,0);
	else if (type==DATA_REG)
	    use_data_reg(dreg,0);
if (regv[dreg]) {
    printf("# emit_pop dreg conflict\n");
}
	printf("\tpopl %s\n",register_name(dreg,0));
	xreg = dreg;
	regv[xreg]=1;
    } 
    return xreg;
}

static void
emit_pop_free(int xreg)
{
    if (xreg==dreg) {
	regv[dreg]=0;
    } else if (xreg!=-1) {
	free_register(xreg);
    }
}

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 */
            regv[i]=0;
	    return i;       /* その場所を表す番号を返す */
	}
    }
    return -1;
}

void
gexpr(int e1)
{
    gexpr_init();
#if 0
    if(lineno==2862) {
        g_expr(e1); /*break here*/
        return;
    } 
#endif
    g_expr(e1);
}

int
csvalue()
{
    return rname[creg]; /* for switch 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",(char *)caddr(e1),register_name(creg,0));
	regv[creg]=1;
	return;
    case RGVAR:
	/* use_pointer(creg,0); */
	printf("\tmovl %s,%s\n",(char *)caddr(e1),register_name(creg,0));
	regv[creg]=1;
	return;
    case CRGVAR:
	printf("\tmovsbl %s,%s\n",(char *)caddr(e1),register_name(creg,0));
	regv[creg]=1;
	return;
    case LVAR:
	/* use_pointer(creg,0); */
	printf("\tlea %d(%%ebp),%s\n",lvar(e2),register_name(creg,0));
	regv[creg]=1;
	return;
    case REGISTER:
	/* this is of course redundant... */
	/* we can use rname for this? */
	/* or why not creg=e2? */
	printf("\tmovl %s,%s\n",register_name(e2,0),register_name(creg,0));
	regv[creg]=1;
	return;
    case RLVAR:
	printf("\tmovl %d(%%ebp),%s\n",lvar(e2),register_name(creg,0));
	regv[creg]=1;
	return;
    case CRLVAR:
	printf("\tmovsbl %d(%%ebp),%s\n",lvar(e2),register_name(creg,0));
	regv[creg]=1;
	return;
    case FNAME:
	printf("\tmovl $%s,%s\n",((NMTBL *)e2)->nm,register_name(creg,0));
	regv[creg]=1;
	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,register_name(creg,0));
	regv[creg]=1;
	return;
    case STRING:
	string(e1);
	regv[creg]=1;
	return;
    case FUNCTION:
	function(e1);
	regv[creg]=1;
	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", register_name(creg,0));
	return;
    case BNOT:   /* ~ */
	g_expr(e2);
	/* use_data_reg(creg,1); */
	printf("\tnotl %s\n", register_name(creg,0));
	return;
    case LNOT:   /* !  */
	g_expr(e2);
	use_data_reg(creg,1);
	xrn = register_name(creg,1);
	printf("\tcmpl $0,%s\n", register_name(creg,0));
	printf("\tsete %s\n", xrn);
	printf("\tmovzbl %s,%s\n", xrn,register_name(creg,0));
	return;
    case PREINC:
	if (car(e2)==REGISTER) {
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2),0));
	    printf("\tmovl %s,%s\n",register_name(cadr(e2),0),register_name(creg,0));
	    return;
	} 
	g_expr(e2);
	xrn = register_name(creg,0);
	printf("\taddl $%d,(%s)\n",caddr(e1),xrn);
	printf("\tmovl (%s),%s\n",xrn,xrn);
	return;
    case POSTINC:
	if (car(e2)==REGISTER) {
	    printf("\tmovl %s,%s\n",register_name(cadr(e2),0),register_name(creg,0));
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2),0));
	    return;
	} 
	g_expr(e2);
	emit_push();  
	xrn = register_name((e2=emit_pop(0)),0);
	printf("\tmovl (%s),%s\n",xrn,register_name(creg,0));
	printf("\taddl $%d,(%s)\n",caddr(e1),xrn);
	emit_pop_free(e2);
	return;
    case CPOSTINC:
	/*   char *p; *p++ */
	if (car(e2)==REGISTER) {
	    printf("\tmovl %s,%s\n",register_name(cadr(e2),0),register_name(creg,0));
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2),0));
	    return;
	} 
	g_expr(e2);
	emit_push();
	xrn = register_name((e2=emit_pop(0)),1);
	printf("\tmovsbl (%s),%s\n",xrn,register_name(creg,0));
	printf("\tincl (%s)\n",xrn);
	emit_pop_free(e2);
	return;
    case CPREINC:
	if (car(e2)==REGISTER) {
	    printf("\taddl $%d,%s\n",caddr(e1),register_name(cadr(e2),0));
	    printf("\tmovl %s,%s\n",register_name(cadr(e2),0),register_name(creg,0));
	    return;
	} 
	g_expr(e2);
	printf("\tincl (%s)\n",register_name(creg,0));
	printf("\tmovsbl (%s),%s\n",register_name(creg,0),register_name(creg,0));
	return;
    case CPOSTDEC:
	if (car(e2)==REGISTER) {
	    printf("\tmovl %s,%s\n",register_name(cadr(e2),0),register_name(creg,0));
	    printf("\tdecl %s\n",register_name(cadr(e2),0));
	    return;
	} 
	g_expr(e2);
	printf("\tmovsbl (%s),%s\n",register_name(creg,0),register_name(creg,0));
	printf("\tdecl (%s)\n",register_name(creg,0));
	return;
    case CPREDEC:
	if (car(e2)==REGISTER) {
	    printf("\tdecl %s\n",register_name(cadr(e2),0));
	    printf("\tmovl %s,%s\n",register_name(cadr(e2),0),register_name(creg,0));
	    return;
	} 
	g_expr(e2);
	emit_push();
	e2 = emit_pop(0);
	printf("\tdecl (%s)\n",register_name(e2,0));
	printf("\tmovsbl (%s),%s\n",register_name(e2,0),register_name(creg,0));
	emit_pop_free(e2);
	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,e2,0);
	use_register(creg,REG_EAX,0);
	g_expr(caddr(e1));
	/* e4 = rname[creg]; this is a bad idea */
	use_register(creg,REG_EAX,1);
	jmp(e3=fwdlabel());
	fwddef(e2);
	use_register(creg,REG_EAX,0);
	g_expr(cadddr(e1));
	/* use_register(creg,e4,1); */
	use_register(creg,REG_EAX,1);
	fwddef(e3);
	return;
    case STASS: 
	sassign(e1);
	return;
    case ASS: case CASS:
	assign(e1);
	return;
    case ASSOP: case CASSOP:
	assop(e1);
	return;
    case RSTRUCT:
	g_expr(e2);
	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,register_name(creg,0));
	regv[creg]=1;
	return;
    case ENVIRONMENT:
	printf("\tmovl %%ebp,%s\n",register_name(creg,0));
	regv[creg]=1;
	return;
    default:
	b_expr(e1,1,e2=fwdlabel(),1);  /* including > < ... */
	xrn = register_name(creg,0);
	printf("\txorl %s,%s\n",xrn,xrn);
	jmp(e3=fwdlabel());
	fwddef(e2);
	printf("\tmovl $1,%s\n",xrn);
	fwddef(e3);
	regv[creg]=1;
    }
}

void
bexpr(int e1, char cond, int l1)
{
    gexpr_init();
    b_expr(e1,cond,l1,0);
}

void
b_expr(int e1, char cond, int l1,int err)
{
    int e2,l2;
    if (chk) return;
    e2=cadr(e1);
    switch(car(e1)) {
    case LNOT:
	b_expr(e2,!cond,l1,0);
	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()):l1,0);
	b_expr(caddr(e1),cond,l1,0);
	if(cond) fwddef(l2);
	return;
    case LOR:
	b_expr(e2,1,cond?l1:(l2=fwdlabel()),0);
	b_expr(caddr(e1),cond,l1,0);
	if(!cond) fwddef(l2);
	return;
    case CRGVAR:
	printf("\tcmpb $0,%s\n",(char *)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",(char *)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(e2,0));
	jcond(l1,cond);
	return;
    case CONST:
	if((cond&&e2)||(!cond&&!e2)) jmp(l1);
	return;
    default:
	if(err) {
	    error(-1); return; /* recursice g_expr/b_expr */
	}
	g_expr(e1);
	printf("\tcmpl $0,%s\n",register_name(creg,0));
	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,register_name(creg,0));
    } 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,register_name(creg,0));
    }
}

#define MAX_COPY_LEN 20

void 
emit_copy(int from,int  to,int length,int offset,int value,int det)
{
    int fix = 0;
    /* length <0 means upward direction copy */
    switch (length) {
    case 0:	break;
    case 1: case -1:
	printf("\tmovb %d(%s),%s\n",offset,register_name(from,0), reg_name_l[rname[dreg]] );
	printf("\tmovb %s,%d(%s)\n",reg_name_l[rname[dreg]] ,offset,register_name(to,0));
	break;
    case 2: case -2:
	printf("\tmovw %d(%s),%s\n",offset,register_name(from,0), reg_name_w[rname[dreg]] );
	printf("\tmovw %s,%d(%s)\n",reg_name_w[rname[dreg]] ,offset,register_name(to,0));
	break;
    case 4: case -4:
	printf("\tmovl %d(%s),%s\n",offset,register_name(from,0), register_name(dreg,0));
	printf("\tmovl %s,%d(%s)\n",register_name(dreg,0), offset,register_name(to,0));
	break;
    default:
	if (-MAX_COPY_LEN<length && length <0) {
	    for(;length<=4;length+=4,offset-=4)
		emit_copy(from,to,4,offset,0,det);
	    for(;length<=2;length+=2,offset-=2)
		emit_copy(from,to,2,offset,0,det);
	    if(length>0)
		emit_copy(from,to,length,offset,0,det);
	    break;
	} else if (length <=MAX_COPY_LEN) {
	    for(;length>=4;length-=4,offset+=4)
		emit_copy(from,to,4,offset,0,det);
	    for(;length>=2;length-=2,offset+=2)
		emit_copy(from,to,2,offset,0,det);
	    if(length>0)
		emit_copy(from,to,length,offset,0,det);
	    break;
	}
	if (det) {
/*
   call bcopy
	    g_expr(list3(FUNCTION,,);
	    break;
 */
	}
	use_register(from,REG_ESI,1);
	use_register(to,  REG_EDI,1);
	use_register(dreg,REG_ECX,0);
	if (length<0) {
	    printf("\tmovl $%d,%%ecx\n",-length/4);
	    printf("\taddl $%d,%%esi\n",-length);
	    printf("\taddl $%d,%%edi\n",-length);
	    printf("\tstd\n\trep\n\tmovsl\n");
	    if(length%4) {
		emit_copy(from,to,length,offset+length/4,0,det);
	    }
	} else {
	    printf("\tmovl $%d,%%ecx\n",length/4);
	    fix = (length/4)*4;
	    printf("\tcld\n\trep\n\tmovsl\n");
	    if(length%4) {
		emit_copy(from,to,length,offset+length/4,0,det);
	    }
	}
    }
    if (value) {
    /* creg must point top of the destination data */
    /* this code is necessary for the value of assignment or function call */
    /* otherwise we don't need this */
	if (fix) printf("\tsubl $%d,%s\n",fix,register_name(to,0));
	if(creg!=to) {
	    if (to==dreg) 
		printf("\tmovl %s,%s\n",register_name(to,0),register_name(creg,0));
	    else {
		free_register(creg); creg=to;
	    }
	}
    }
    regv[from]=regv[to]=regv[dreg]=0;
    regv[creg]=1;
}

int
struct_push(int e4,int t) 
{
    int length,xreg,save,lreg;
    g_expr(e4);
    length=size(t); 
    if(length%size_of_int) {
	length += size_of_int - (length%size_of_int);
    }
    if (length==4) {
	printf("\tpushl (%s)\n",register_name(creg,0)); return 1;
    }
    if (length==8) {
	printf("\tpushl 4(%s)\n",register_name(creg,0));
	printf("\tpushl (%s)\n",register_name(creg,0)); return 2;
    }
    printf("\tsubl $%d,%%esp\n",length);
    if (register_full()) {
	save = 1;
	for(lreg=0;lreg==creg||lreg==dreg;lreg++);
	printf("\tpushl %s\n",register_name(lreg,0));
	xreg = lreg; regv[xreg]=0;
    } else {
	save=0;
	xreg = get_register();
    }
    if (save) 
	printf("\tlea %d(%%esp),%s\n",size_of_int,register_name(xreg,0));
    else
	printf("\tmovl %%esp,%s\n",register_name(xreg,0));
    regv[xreg]=1;
    /* downward direction copy */
    emit_copy(creg,xreg,length,0,0,1);
    /* we have value in creg, it may be changed */
    if (save) {
	if(creg==xreg) {
	    creg = get_register();   /* creg is freed in emit_copy */
	}
	printf("\tpopl %s\n",register_name(xreg,0));
	regv[xreg]=1;
    } else
	free_register(xreg);
    return length/size_of_int;
}

void
function(int e1)
{
    int e2,e3,e4,e5,nargs,t;
    NMTBL *n;
    int save,saved;
    if (free_register_count()<1) {
        for(save = 0;save==dreg||save==creg;save++);
	printf("\tpushl %s\n",register_name(save,0));
        saved = 1;
    } else {
        save = get_register();
        saved = 0;
    }
    regv[save]=0;
    e2 = cadr(e1);
    nargs = 0;
    for (e3 = caddr(e1); e3; e3 = cadr(e3)) {	
	t=caddr(e3);
	n=(NMTBL *)(e5=(cadr(e4 = car(e3))));
	if(scalar(t)) {
	    g_expr(e4);
	    printf("\tpushl %s\n",register_name(creg,0));
	} else if (car(t)==STRUCT||car(t)==UNION) {
	    nargs += struct_push(e4,t);
	    continue;
	} else {
	    error(TYERR);
	}
	++nargs;
    }
    if (car(e2) == FNAME) {	
	n=(NMTBL *)cadr(e2);
    } else {	
        use_register(creg,REG_EAX,0);
	g_expr(e2);
    }

    /* we don't have to save creg nor dreg */
    regs[creg]=0; regs[dreg]=0;
    regv[creg]= regv[dreg]= regv[save]= 0;
    use_register(creg,REG_EAX,0);
    use_register(dreg,REG_EDX,0);  /* will be destroyed */
    use_register(save,REG_ECX,0);  /* will be destroyed */
    regs[creg]=1; regs[dreg]=1;

    if (car(e2) == FNAME) {	
	printf("\tcall\t%s\n",n->nm);
    } else {
	printf("\tcall\t*%s\n",register_name(creg,0));
    }
    if (nargs) printf("\taddl $%d,%%esp\n",size_of_int*nargs);
    if (saved) {
	printf("\tpopl %s\n",register_name(save,0));
    } else {
        free_register(save);
    }
    regv[save]=0;
    regv[creg]=1;
}

/* goto arguments list                                      */
/* target         list4(list2(tag,disp),cdr,ty,source_expr) */
/*     source         expr=listn(tag,...)                   */
/*     source (after) list2(tag,disp)                       */
/* source list    list3(e,cdr,sz)                           */

#define DEBUG_PARALLEL_ASSIGN 1

int
overrap(int t,int sz,int source)
{
    int s,s0,s1;
    int t0=cadr(t);
    int t1=t0+sz;
    for(;source;source=cadr(source)) {
	s=car(source); s0=cadr(s); 
	if(car(s)==REGISTER && car(t)==REGISTER) {
	    if(s0==t0) return s;
	} else if (is_same_type(s,t)) {
	    s1=s0+caddr(source);
#if DEBUG_PARALLEL_ASSIGN>1 
printf("# ovedrrap source %d t0 %d t1 %d\n",car(car(t)),t0,t1);
printf("# ovedrrap target %d s0 %d s1 %d\n",car(car(source)),s0,s1);
printf("# ovedrrap   equal = %d\n",((t0<=s0&&s0<t1)||(t0<s1&&s1<=t1)));
#endif
	    if((t0<=s0&&s0<t1)||(t0<s1&&s1<=t1)) return s;
	}
    }
    return 0;
}

void
remove_target(int *target,int t,int *use)
{
    int use0=*use;
    while(use0) {
	if (car(use0)==t) {
	    free_register(caddr(use0));
	    break;
	}
	use0 = cadr(use0);
    }
    remove0(target,t);
}

void
save_target(int t,int s,int *target,int *use,int sz,int ty)
{
    int e1;
    /*新しいレジスタ(or スタック)を取得する*/
    if (sz==size_of_int && (e1=get_register())!=-1) {
	*use=list3(t,*use,e1);
	e1=list2(REGISTER,e1);
	g_expr(assign_expr0(e1,s,ty,ty));
	*target = append4(*target,t,ty,e1);
    } else {
	disp-=sz;
	g_expr(assign_expr0((e1=list2(LVAR,disp)),s,ty,ty));
	*target = append4(*target,t,ty,e1);
    }
}

int
circular_dependency(int t,int s,int *target,int *source)
{
    int target0=*target;
    int t1,sz,ty,s1;
    while(target0) {
	if (cadddr(target0)==s) {
	    t1=car(target0); 
	    s=cadddr(target0);
	    sz=size(ty=caddr(target0)); 
	    if(t==t1) {
#if DEBUG_PARALLEL_ASSIGN
printf("# circular dependency %d ty %d+%d sz %d\n",car(t1),ty,cadr(t1),sz);
#endif
		return 1;
	    }
	    if ((s1=overrap(t1,sz,*source))) {
		/* another overrap start over */
		return circular_dependency(t,s1,target,source);
	    }
	}
	target0=cadr(target0);
    }
    return 0;
}

void
parallel_assign(int *target,int *source,int *processing,int *use)
{
    int t,s,sz,ty,target0,s1;
    while(*target) {
	target0=*target;
	while(target0) {
	    t=car(target0); s=cadddr(target0);
	    sz=size(ty=caddr(target0)); 
	    if(car(t)==car(s) && cadr(t)==cadr(s)) {
		/*書き込み先が自分自身*/
#if DEBUG_PARALLEL_ASSIGN
printf("# remove same %d ty %d+%d sz %d\n",car(t),ty,cadr(t),sz);
#endif
		remove_target(target,t,use);
		/* 破壊されては困るので、source listからは除かない */
	    } else if (!(s1=overrap(t,sz,*source))) {
		/* 重なってないので安心して書き込める */
#if DEBUG_PARALLEL_ASSIGN
printf("# normal assign %d ty %d+%d sz %d\n",car(t),ty,cadr(t),sz);
#endif
		g_expr(assign_expr0(t,s,ty,ty));
		remove_target(target,t,use); remove0(source,s);
	    } else {
		if(circular_dependency(t,s1,target,source)) {
#if DEBUG_PARALLEL_ASSIGN
    printf("# saving %d ty %d+%d sz %d\n",car(t),ty,cadr(t),sz);
#endif
		    remove_target(target,t,use); remove0(source,s);
		    save_target(t,s,target,use,sz,ty);
		}
	    }
	    target0=cadr(target0);
	}
    }
}

void 
remove0(int *parent,int e) 
{
    int list;
    while ((list=*parent)) {
	if (car(list)==e) {
	    *parent= cadr(list); return;
	} else {
	     parent=&cadr(list);
	}
    }
}

void 
remove0_all(int *parent,int e) 
{
    int list;
    while ((list=*parent)) {
	if (car(list)==e) {
	    *parent= cadr(list);
	} else {
	     parent=&cadr(list);
	}
    }
}

int
is_simple(int e1) 
{
    return (
	e1==CONST || e1==FNAME || e1==LVAR || e1==REGISTER ||
	e1==GVAR || e1==RGVAR || e1==RLVAR || e1==CRLVAR || e1==CRGVAR
    );
}

int
is_same_type(int e1,int e2)
{
    int ce1=car(e1);
    int ce2=car(e2);
    return (   
         (ce1==LVAR && (ce2==RLVAR||ce2==CRLVAR))
      || (ce2==LVAR && (ce1==RLVAR||ce1==CRLVAR))
      || (ce1==GVAR && (ce2==RGVAR||ce2==CRGVAR))
      || (ce2==GVAR && (ce1==RGVAR||ce1==CRGVAR))
    );
}

int
is_memory(int e1)
{
    int ce1=car(e1);
    return (   
         ce1==LVAR ||ce1==RLVAR||ce1==CRLVAR ||
         ce1==GVAR ||ce1==RGVAR||ce1==CRGVAR ||
         ce1==REGISTER
    );
}

void
jump(int e1, int env)
{
    int e2,e3,e4,sz,arg_size,ty,max_regs,regs;
    int t0,s0;
    NMTBL *code0;
    int target = 0;
    int source = 0;
    int processing = 0;
    int use = 0;

    /* まず、サイズを計算しながら、決まった形に落す。 */

    arg_size = 0; regs = 0; max_regs = MAX_REGISTER_VAR-1;
    for (e3 = reverse0(caddr(e1)); e3; e3 = cadr(e3)) {	
	e2 = car(e3); sz = size(ty=caddr(e3)); 
	if (regs <= max_regs&&scalar(ty)) {
	    target=list4(list2(REGISTER,virtual((regs++)+REG_ESI)),
		target,ty,e2);
	} else {
	    target=list4(list2(LVAR,0),
		target,ty,e2);
	    arg_size += sz;
	}
#if DEBUG_PARALLEL_ASSIGN
printf("# target %d ty %d+%d sz %d\n",car(car(target)),ty,cadr(car(target)),sz);
#endif
    }

    /* disp を飛び先似合わせて修正 */
    if (fnptr->sc==CODE) {
	if (-arg_size<disp) disp = -arg_size;
	jump_offset = 0;
    } else {
	if (disp_offset-arg_size<disp) disp = disp_offset-arg_size;
	jump_offset = 0;
    }

    /*  複雑な式を前もって計算しておく     */
    /*  必要なら局所変数を用いる。         */
    /*  局所変数へのオフセットを覚えておく */

    for (e2 = target; e2; e2 = cadr(e2)) {	
	t0=car(e2); s0=cadddr(e2);
	sz=size(ty=caddr(e2));
	if(car(t0)==LVAR) {
	    /* ここで、書込先アドレスを決める */
	    cadr(t0)=-arg_size+jump_offset;
	    arg_size-=sz;
	}
	if (!is_simple(car(s0))) {
	    disp-=sz;
	    g_expr(assign_expr0((e4=list2(LVAR,disp)),s0,ty,ty));
	    cadddr(e2)=e4;
	    s0=e4;
        } else if (is_same_type(t0,s0)) {
            if(cadr(t0)==cadr(s0)) {
#if DEBUG_PARALLEL_ASSIGN
printf("# remove same memory %d ty %d+%d sz %d\n",car(t0),ty,cadr(t0),sz);
#endif
                /* we should check size also (but currently useless */
                remove0(&target,t0);
                /* still we have source to avoid overwrite */
	    }
        }
	if(is_memory(s0)) {
	    source=list3(s0,source,sz);
#if DEBUG_PARALLEL_ASSIGN
printf("# source %d ty %d+%d sz %d\n",car(car(source)),ty,cadr(car(source)),sz);
#endif
	}
    }

    /* compute jump address */
    e2 = cadr(e1);
    if (car(e2) == FNAME) {	
	code0=(NMTBL *)cadr(e2);
	if (code0->sc!=CODE) {
	    error(TYERR); return;
	}
    } else {	/* indirect */
	g_expr(e2);
	emit_push();
    }
    if (env) {
	g_expr(env);
	emit_push();
    }

    /* 並列代入を実行 */

    parallel_assign(&target,&source,&processing,&use);
    while (use) {
	free_register(caddr(use)); use=cadr(use);
    }
    if(target) error(-1);

    if (env) {
	/* change the frame pointer */
	e3 = emit_pop(0);
	printf("\tmovl %s,%%ebp\n",register_name(e3,0));
	emit_pop_free(e3);
    } else if (fnptr->sc==FUNCTION) {
	printf("\tlea %d(%%ebp),%%ebp\n",disp_offset);
    } 

    if (car(e2) == FNAME) {	
	printf("\tjmp %s\n",code0->nm);
    } else {
	e2 = emit_pop(0);
	printf("\tjmp *%s\n",register_name(e2,0));
	emit_pop_free(e2);
    }
}

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),(e2=pop_register()));
    emit_pop_free(e2);
    regv[creg]=1;
    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,register_name(creg,0),register_name(creg,0));
}

void
sassign(int e1)
{
    int e2,e3,e4,sz,xreg,det;

    /* structure assignment */
    e2 = cadr(e1);  /* pointer variable to the struct */
    e3 = cadr(e2);  /* offset of the variable (distination) */
    e4 = caddr(e1); /* right value (source) */
    sz = cadddr(e1);  /* size of struct or union */
    g_expr(e4);
    emit_push();
    g_expr(e2);
    xreg = emit_pop(0);
    /* 一般的にはコピーのオーバラップの状況は実行時にしかわからない */
    /* しかし、わかる場合もある */
    if (car(e4)==RSTRUCT) e4=cadr(e4);
    if (is_same_type(e2,e4)) {
	if(cadr(e2)<cadr(e4)) sz=-sz;
	det=1;
    } else {
	det = 0;
    }
    emit_copy(xreg,creg,sz,0,1,det);
    emit_pop_free(xreg);
    return;
}

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

    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,register_name(creg,byte),(char *)caddr(e2));
            return;
    case LVAR:
            g_expr(e4);
            if (byte) use_data_reg(creg,1);
            printf("\t%s %s,%d(%%ebp)\n",op,register_name(creg,byte),lvar(cadr(e2)));
            return;
    case REGISTER:
            g_expr(e4);
	    if (creg!=cadr(e2))
		printf("\tmovl %s,%s\n",register_name(creg,0),register_name(cadr(e2),0));
            return;
    }
    g_expr(e2);
    emit_push();
    use_data_reg(creg,0);
    g_expr(e4);
    if (byte) use_data_reg(creg,1);
    e2 = emit_pop(0);
    printf("\t%s %s,(%s)\n",op,register_name(creg,byte),register_name(e2,0));
    emit_pop_free(e2);
    regv[creg]=1;
    return;
}

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

    /*   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);
    if (car(e2)==REGISTER) {
	xreg = creg;
	creg = reg = cadr(e2);
	tosop(op,xreg);
	creg = xreg;
	printf("\tmovl %s,%s\n",register_name(reg,0),register_name(creg,0));
	regv[creg]=1;
	return;
    }
    emit_push();
    g_expr(e2);
    edx = edx_setup();
    xrn = register_name(xreg = emit_pop(0),0);       /* pop e3 value */
    regv[xreg]=regs[xreg]=1;
    printf("\tmovl %s,%s  # assop \n",register_name(creg,0),register_name(edx,0));
    regv[edx]=1;
    ld_indexx(byte,0,edx);
    tosop(op,xreg);
    printf("\t%s %s,(%s)\n",byte ? "movb" : "movl",register_name(creg,byte),register_name(edx,0));
    edx_cleanup();
    emit_pop_free(xreg);
    regv[creg]=1;
    return;
}


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

    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",register_name(dreg,0));
	oreg = dreg;
	regv[dreg]=1;
    }
    regv[oreg]=1; regs[oreg]=1;
    orn = register_name(oreg,0);
    crn = register_name(creg,0);
    switch(op) {
    case ADD:
	printf("\taddl %s,%s\n",orn,crn);
	break;
    case SUB:
	printf("\tsubl %s,%s\n",orn,crn);
	break;
    case BAND: 
	printf("\tandl %s,%s\n",orn,crn);
	break;
    case EOR: 
	printf("\txorl %s,%s\n",orn,crn);
	break;
    case BOR:
	printf("\torl %s,%s\n",orn,crn);
	break;
    case MUL:
    case UMUL:
	printf("\t%s %s,%s\n","imull",orn,crn);
	break;
    case DIV:
    case UDIV:
	use_register(creg,REG_EAX,1);
	edx_setup();
	orn = register_name(oreg,0);
	if (op==DIV)
	    printf("\tcltd\n\tdivl %s\n",orn);
	else 
	    printf("\txor %%edx,%%edx\n\tidivl %s\n",orn);
	edx_cleanup();
	break;
    case MOD:
    case UMOD:
	use_register(creg,REG_EAX,1);
	edx_setup();
	orn = register_name(oreg,0);
	if (op==DIV)
	    printf("\tcltd\n\tdivl %s\n",orn);
	else 
	    printf("\txor %%edx,%%edx\n\tidivl %s\n",orn);
        dx = virtual(REG_EDX);	
	if (dx!=creg) {
	    rname[dx]=rname[creg];
	    rname[creg]=REG_EDX;
	}
	edx_cleanup();
	break;
    }
    if (oreg!=dreg&&oreg>=0)
	free_register(oreg);
}

static int edx_stack=0;

int
edx_setup()
{
    int edx_save;
    /* make real EDX register empty */
    if (free_register_count()<1) {
        for(edx_save = 0;edx_save==dreg||edx_save==creg;edx_save++);
	printf("\tpushl %s\n",register_name(edx_save,0));
        edx_stack = list3(edx_save,edx_stack,0);
    } else {
        edx_save = get_register();
        edx_stack = list3(edx_save,edx_stack,1);
    }
    regv[edx_save]=0;
    use_register(edx_save,REG_EDX,0);
    return edx_save;
}


void
edx_cleanup()
{
    if (caddr(edx_stack)==0) {
	printf("\tpopl %s\n",register_name(car(edx_stack),0));
    } else
	free_register(car(edx_stack));
    edx_stack = cadr(edx_stack);
}

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

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

    op = byte ? "movsbl" : "movl";
    if (n) 
	    printf("\t%s %d(%s),%s\n",op,n,register_name(xreg,0),register_name(creg,byte));
    else
	    printf("\t%s (%s),%s\n",op,register_name(xreg,0),register_name(creg,byte));
}

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

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
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? */
    /*
      this is not allowed because of ? operator
    regv[creg]=regv[dreg]=0; 
    use_register(creg,REG_EAX,0);
    use_register(dreg,REG_EBX,0);
     */
}

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)
{
    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 args)
{
    code_disp_label=fwdlabel();
    printf("\tlea _%d(%%ebp),%%esp\n",code_disp_label);

printf("## args %d disp %d code_arg_offset=%d code_disp_offset=%d\n",args,disp,code_arg_offset,code_disp_offset); 
}

void
code_leave(char *name)
{
    disp=(disp-(size_of_int-1))&(-(size_of_int-1));
    printf("\t.set _%d,%d\n",code_disp_label,disp+code_disp_offset);
    printf("_%d:\n",labelno);
    printf("\t.size\t%s,_%d-%s\n",name,labelno,name);
    local_table();
    labelno++;
    free_all_register();
}

void
enter(char *name)
{
    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 %%esi\n");
    printf("\tpushl %%edi\n");
}

void
enter1()
{
    func_disp_label=fwdlabel();
    printf("\tlea _%d(%%ebp),%%esp\n",func_disp_label); 
    /* 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],register_name(creg,0));
	/* printf("\tleave\n"); */
    }
    fwddef(retlabel);
    /* use_register(creg,REG_EAX,0); too late */
    /* if(disp) printf("\taddl $%d,%%esp\n",-disp);  */
    printf("\tlea %d(%%ebp),%%esp\n",disp_offset);
    printf("\tpopl %%edi\n");
    printf("\tpopl %%esi\n");
    printf("\tpopl %%ebx\n");
    printf("\tleave\n");
    printf("\tret\n");
    disp=(disp-(size_of_int-1))&(-(size_of_int-1));
    printf("\t.set _%d,%d\n",func_disp_label,disp+disp_offset);
    printf("_%d:\n",labelno);
    printf("\t.size\t%s,_%d-%s\n",name,labelno,name);
    local_table();
    labelno++;
    free_all_register();
}


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)  { 
	error(-1); return;
    }
    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 += size_of_int;
	}
    } else if(t!=CHAR) {       
	gpc += size_of_int;
	if(car(e)==ADDRESS&&car(cadr(e))==GVAR) {
	    printf("\t.long %s\n",(char *)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);
    }
}

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;
    int init;
    init=0;
    for(n=ntable;n < &ntable[GSYMS];n++) {
	if (n->sc == GVAR && n->dsp != -1) {
	    /* n->dsp = -1 means initialized global */
	    if (init==0) {
		data_mode(0);
		init=1;
	    }
	    printf(".comm %s,%d\n",n->nm,size(n->ty));
	}
    }
}

void
local_table(void)
{
    NMTBL *n;
    int init;
    init=0;
    /* static local variables */
    for(n=ntable+GSYMS;n < &ntable[GSYMS+LSYMS];n++) {
	if (n->sc == GVAR) {
	    if (init==0) {
		data_mode(0);
		init=1;
	    }
	    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 (fnptr->sc==CODE) {
	return l+code_disp_offset;
    } else if (l<0) {
	return l+disp_offset;
    } else {
	return l+arg_offset;
    }
}


/* end */