ack/lang/cem/cemcom/em.c
1986-03-10 13:07:55 +00:00

220 lines
3.2 KiB
C

/* $Header$ */
/* EM CODE OUTPUT ROUTINES */
#define CMODE 0644
#define MAX_ARG_CNT 32
#include "em.h"
#include "system.h"
#include "bufsiz.h"
#include "arith.h"
#include "label.h"
/*
putbyte(), C_open() and C_close() are the basic routines for
respectively write on, open and close the output file.
The put_*() functions serve as formatting functions of the
various EM language constructs.
See "Description of a Machine Architecture for use with
Block Structured Languages" par. 11.2 for the meaning of these
names.
*/
/* supply a kind of buffered output */
#define flush(x) sys_write(ofd, &obuf[0], x);
static char obuf[BUFSIZ];
static char *opp = &obuf[0];
int ofd = -1;
putbyte(b) /* shouldn't putbyte() be a macro ??? (EB) */
int b;
{
if (opp >= &obuf[BUFSIZ]) { /* flush if buffer overflows */
flush(BUFSIZ);
opp = &obuf[0];
}
*opp++ = (char) b;
}
C_open(nm) /* open file for compact code output */
char *nm;
{
if (nm == 0)
ofd = 1; /* standard output */
else
if ((ofd = sys_creat(nm, CMODE)) < 0)
return 0;
return 1;
}
C_close()
{
flush(opp - &obuf[0]);
opp = obuf; /* reset opp */
sys_close(ofd);
ofd = -1;
}
C_busy()
{
return ofd >= 0; /* true if code is being generated */
}
/*** front end for generating long CON/ROM lists ***/
static arg_count;
static arg_rom;
DC_start(rom){
arg_count = 0;
arg_rom = rom;
}
DC_check(){
if (arg_count++ >= MAX_ARG_CNT) {
switch (arg_rom) {
case ps_con:
C_con_end();
C_con_begin();
break;
case ps_rom:
C_rom_end();
C_rom_begin();
break;
}
}
}
/*** the compact code generating routines ***/
#define fit16i(x) ((x) >= (long)0xFFFF8000 && (x) <= (long)0x00007FFF)
#define fit8u(x) ((x) <= 0xFF) /* x is already unsigned */
put_ilb(l)
label l;
{
if (fit8u(l)) {
put8(sp_ilb1);
put8((int)l);
}
else {
put8(sp_ilb2);
put16(l);
}
}
put_dlb(l)
label l;
{
if (fit8u(l)) {
put8(sp_dlb1);
put8((int)l);
}
else {
put8(sp_dlb2);
put16(l);
}
}
put_cst(l)
arith l;
{
if (l >= (arith) -sp_zcst0 && l < (arith) (sp_ncst0 - sp_zcst0)) {
/* we can convert 'l' to an int because its value
can be stored in a byte.
*/
put8((int) l + (sp_zcst0 + sp_fcst0));
}
else
if (fit16i(l)) { /* the cast from long to int causes no trouble here */
put8(sp_cst2);
put16((int) l);
}
else {
put8(sp_cst4);
put32(l);
}
}
put_doff(l, v)
label l;
arith v;
{
if (v == 0)
put_dlb(l);
else {
put8(sp_doff);
put_dlb(l);
put_cst(v);
}
}
put_noff(s, v)
char *s;
arith v;
{
if (v == 0)
put_dnam(s);
else {
put8(sp_doff);
put_dnam(s);
put_cst(v);
}
}
put_dnam(s)
char *s;
{
put8(sp_dnam);
put_str(s);
}
put_pnam(s)
char *s;
{
put8(sp_pnam);
put_str(s);
}
#ifdef ____
put_fcon(s, sz)
char *s;
arith sz;
{
put8(sp_fcon);
put_cst(sz);
put_str(s);
}
#endif ____
put_wcon(sp, v, sz) /* sp_icon, sp_ucon or sp_fcon with int repr */
int sp;
char *v;
arith sz;
{
/* how 'bout signextension int --> long ??? */
put8(sp);
put_cst(sz);
put_str(v);
}
put_str(s)
char *s;
{
register int len;
put_cst((arith) (len = strlen(s)));
while (--len >= 0)
put8(*s++);
}
put_cstr(s)
char *s;
{
register int len = prepare_string(s);
put8(sp_scon);
put_cst((arith) len);
while (--len >= 0)
put8(*s++);
}