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C!T ROM 2
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ctrom_ii_b.zip
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ctrom_ii_b
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PROGRAM
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C
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SMALL_C
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CC33.C
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1987-10-04
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5KB
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201 lines
/*
** Small C - 8088/8086 version - modified by R. Grehan, BYTE Magazine
**
** true if val1 -> int pointer or int array and val2 not ptr or array
*/
dbltest(oper, val1, val2) int (*oper)(), val1[], val2[]; {
if((oper!=ffadd) && (oper!=ffsub)) return 0;
if(val1[2]!=CINT) return 0;
if(val2[2]) return 0;
return 1;
}
/*
** determine type of binary operation
*/
result(lval, lval2) int lval[], lval2[]; {
if((lval[2]!=0)&(lval2[2]!=0)) {
lval[2]=0;
}
else if(lval2[2]) {
lval[0]=lval2[0];
lval[1]=lval2[1];
lval[2]=lval2[2];
}
}
step(oper, lval) int (*oper)(), lval[]; {
if(lval[1]) {
if(lval[5]) {
push();
rvalue(lval);
(*oper)(lval[2]>>2);
pop();
store(lval);
return;
}
else {
move();
lval[5]=1;
}
}
rvalue(lval);
(*oper)(lval[2]>>2);
store(lval);
}
store(lval) int lval[]; {
if(lval[1]) putstk(lval);
else putmem(lval);
}
rvalue(lval) int lval[]; {
if ((lval[0]!=0)&(lval[1]==0)) getmem(lval);
else indirect(lval);
}
test(label, parens) int label, parens; {
int lval[8];
char *before, *start;
if(parens) needtoken("(");
while(1) {
setstage(&before, &start);
if(hier1(lval)) rvalue(lval);
if(match(",")) clearstage(before, start);
else break;
}
if(parens) needtoken(")");
if(lval[3]) { /* constant expression */
clearstage(before, 0);
if(lval[4]) return;
jump(label);
return;
}
if(lval[7]) { /* stage address of "oper 0" code */
oper=lval[6]; /* operator function address */
if((oper==ffeq)|
(oper==ule)) zerojump(eq0, label, lval);
else if((oper==ffne)|
(oper==ugt)) zerojump(ne0, label, lval);
else if (oper==ffgt) zerojump(gt0, label, lval);
else if (oper==ffge) zerojump(ge0, label, lval);
else if (oper==uge) clearstage(lval[7],0);
else if (oper==fflt) zerojump(lt0, label, lval);
else if (oper==ult) zerojump(ult0, label, lval);
else if (oper==ffle) zerojump(le0, label, lval);
else testjump(label);
}
else testjump(label);
clearstage(before, start);
}
constexpr(val) int *val; {
int const;
char *before, *start;
setstage(&before, &start);
expression(&const, val);
clearstage(before, 0); /* scratch generated code */
if(const==0) error("must be constant expression");
return const;
}
const(val) int val; {
immed();
outdec(val);
nl();
}
const2(val) int val; {
immed2();
outdec(val);
nl();
}
constant(lval) int lval[]; {
lval=lval+3;
*lval=1; /* assume it will be a constant */
if (number(++lval)) immed();
else if (pstr(lval)) immed();
else if (qstr(lval)) {
*(lval-1)=0; /* nope, it's a string address */
immed();
ot("OFFSET "); /* For MASM -- RG */
printlabel(litlab);
outbyte('+');
}
else return 0;
outdec(*lval);
nl();
return 1;
}
number(val) int val[]; {
int k, minus;
k=minus=0;
while(1) {
if(match("+")) ;
else if(match("-")) minus=1;
else break;
}
if(isdigit(cch)==0)return 0;
while (isdigit(cch)) k=k*10+(inbyte()-'0');
if (minus) k=(-k);
val[0]=k;
return 1;
}
address(ptr) char *ptr; {
immed();
ot("OFFSET "); /* For MASM -- RG */
outlab(ptr+NAME); /* Append underscore -- RG */
nl();
}
pstr(val) int val[]; {
int k;
k=0;
if (match("'")==0) return 0;
while(cch!=39) k=(k&255)*256 + (litchar()&255);
gch();
val[0]=k;
return 1;
}
qstr(val) int val[]; {
char c;
if (match(quote)==0) return 0;
val[0]=litptr;
while (cch!='"') {
if(cch==0) break;
stowlit(litchar(), 1);
}
gch();
litq[litptr++]=0;
return 1;
}
stowlit(value, size) int value, size; {
if((litptr+size) >= LITMAX) {
error("literal queue overflow"); abort(ERRCODE);
}
putint(value, litq+litptr, size);
litptr=litptr+size;
}
/*
** return current literal char & bump lptr
*/
litchar() {
int i, oct;
if((cch!=92)|(nch==0)) return gch();
gch();
if(cch=='n') {gch(); return NEWLINE;}
if(cch=='t') {gch(); return 9;} /* HT */
if(cch=='b') {gch(); return 8;} /* BS */
if(cch=='f') {gch(); return 12;} /* FF */
i=3; oct=0;
while(((i--)>0)&(cch>='0')&(cch<='7')) oct=(oct<<3)+gch()-'0';
if(i==2) return gch(); else return oct;
}