ack/util/ego/share/stack_chg.c
1993-11-16 11:35:23 +00:00

109 lines
1.8 KiB
C

/* $Header$ */
/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* S T A C K _ C H A N G E . C */
#include <stdio.h>
#include <em_spec.h>
#include <em_mnem.h>
#include "types.h"
#include "debug.h"
#include "global.h"
#include "pop_push.h"
#define IS_LOC(l) (l!=(line_p) 0 && INSTR(l)==op_loc && TYPE(l)==OPSHORT)
int stack_change(l,sign)
line_p l;
char sign;
{
/* Interpret the string in the third column of the em_table file */
char *s;
bool argdef;
short arg = 0;
int sum = 0;
line_p p = PREV(l);
line_p pp = (p == (line_p) 0 ? (line_p) 0 : PREV(p));
short i = INSTR(l);
if (i < sp_fmnem || i > sp_lmnem) {
return 0;
}
if (TYPE(l) == OPSHORT) {
arg = SHORT(l);
if (arg < ws) {
/* E.g. a LOI 1 loads word-size bytes,
* not 1 byte!
*/
arg = ws;
}
argdef = TRUE;
} else {
argdef = FALSE;
}
s = pop_push[i];
if (*s == '0') return 0;
while (*s != '\0') {
if (*s++ == sign) {
switch(*s) {
case 'w':
sum += ws;
break;
case 'd':
sum += 2 * ws;
break;
case 'p':
sum += ps;
break;
case 'a':
if (!argdef) return -1;
sum += arg;
break;
case 'x':
if (IS_LOC(p)) {
sum += SHORT(p);
break;
} else {
return -1;
}
case 'y':
if (IS_LOC(pp)) {
sum += SHORT(pp);
break;
} else {
return -1;
}
case '?':
return -1;
default:
assert(FALSE);
}
}
s++;
}
return sum;
}
line_change(l,ok_out,pop_out,push_out)
line_p l;
bool *ok_out;
int *pop_out,*push_out;
{
short pop,push;
pop = stack_change(l,'-');
push = stack_change(l,'+');
*ok_out = (pop != -1 && push != -1);
*pop_out = pop;
*push_out = push;
}