V7M/src/cmd/c/c11.c
#
/*
* C compiler
*/
#include "c1.h"
max(a, b)
{
if (a>b)
return(a);
return(b);
}
degree(at)
struct tnode *at;
{
register struct tnode *t, *t1;
if ((t=at)==0 || t->op==0)
return(0);
if (t->op == CON)
return(-3);
if (t->op == AMPER)
return(-2);
if (t->op==ITOL) {
if ((t1 = isconstant(t)) && (t1->value>=0 || t1->type==UNSIGN))
return(-2);
if ((t1=t->tr1)->type==UNSIGN && opdope[t1->op]&LEAF)
return(-1);
}
if ((opdope[t->op] & LEAF) != 0) {
if (t->type==CHAR || t->type==FLOAT)
return(1);
return(0);
}
return(t->degree);
}
pname(ap, flag)
struct tnode *ap;
{
register i;
register struct tnode *p;
struct { int intx[2]; };
p = ap;
loop:
switch(p->op) {
case LCON:
printf("$%o", flag>10? p->lvalue.intx[1]:p->lvalue.intx[0]);
return;
case SFCON:
case CON:
printf("$");
psoct(p->value);
return;
case FCON:
printf("L%d", (p->value>0? p->value: -p->value));
return;
case NAME:
i = p->offset;
if (flag>10)
i =+ 2;
if (i) {
psoct(i);
if (p->class!=OFFS)
putchar('+');
if (p->class==REG)
regerr();
}
switch(p->class) {
case SOFFS:
case XOFFS:
pbase(p);
case OFFS:
printf("(r%d)", p->regno);
return;
case EXTERN:
case STATIC:
pbase(p);
return;
case REG:
printf("r%d", p->nloc);
return;
}
error("Compiler error: pname");
return;
case AMPER:
putchar('$');
p = p->tr1;
if (p->op==NAME && p->class==REG)
regerr();
goto loop;
case AUTOI:
printf("(r%d)%c", p->nloc, flag==1?0:'+');
return;
case AUTOD:
printf("%c(r%d)", flag==2?0:'-', p->nloc);
return;
case STAR:
p = p->tr1;
putchar('*');
goto loop;
}
error("pname called illegally");
}
regerr()
{
error("Illegal use of register");
}
pbase(ap)
struct tnode *ap;
{
register struct tnode *p;
p = ap;
if (p->class==SOFFS || p->class==STATIC)
printf("L%d", p->nloc);
else
printf("%.8s", &(p->nloc));
}
xdcalc(ap, nrleft)
struct tnode *ap;
{
register struct tnode *p;
register d;
p = ap;
d = dcalc(p, nrleft);
if (d<20 && p->type==CHAR) {
if (nrleft>=1)
d = 20;
else
d = 24;
}
return(d);
}
dcalc(ap, nrleft)
struct tnode *ap;
{
register struct tnode *p, *p1;
if ((p=ap)==0)
return(0);
switch (p->op) {
case NAME:
if (p->class==REG)
return(9);
case AMPER:
case FCON:
case LCON:
case AUTOI:
case AUTOD:
return(12);
case CON:
case SFCON:
if (p->value==0)
return(4);
if (p->value==1)
return(5);
if (p->value > 0)
return(8);
return(12);
case STAR:
p1 = p->tr1;
if (p1->op==NAME||p1->op==CON||p1->op==AUTOI||p1->op==AUTOD)
if (p->type!=LONG)
return(12);
}
if (p->type==LONG)
nrleft--;
return(p->degree <= nrleft? 20: 24);
}
notcompat(ap, ast, op)
struct tnode *ap;
{
register at, st;
register struct tnode *p;
p = ap;
at = p->type;
st = ast;
if (st==0) /* word, byte */
return(at!=CHAR && at!=INT && at!=UNSIGN && at<PTR);
if (st==1) /* word */
return(at!=INT && at!=UNSIGN && at<PTR);
if (st==9 && (at&XTYPE))
return(0);
st =- 2;
if ((at&(~(TYPE+XTYPE))) != 0)
at = 020;
if ((at&(~TYPE)) != 0)
at = at&TYPE | 020;
if (st==FLOAT && at==DOUBLE)
at = FLOAT;
if (p->op==NAME && p->class==REG && op==ASSIGN && st==CHAR)
return(0);
return(st != at);
}
prins(op, c, itable)
struct instab *itable;
{
register struct instab *insp;
register char *ip;
for (insp=itable; insp->op != 0; insp++) {
if (insp->op == op) {
ip = c? insp->str2: insp->str1;
if (ip==0)
break;
printf("%s", ip);
return;
}
}
error("No match' for op %d", op);
}
collcon(ap)
struct tnode *ap;
{
register op;
register struct tnode *p;
p = ap;
if (p->op==STAR) {
if (p->type==LONG+PTR) /* avoid *x(r); *x+2(r) */
return(0);
p = p->tr1;
}
if (p->op==PLUS) {
op = p->tr2->op;
if (op==CON || op==AMPER)
return(1);
}
return(0);
}
isfloat(at)
struct tnode *at;
{
register struct tnode *t;
t = at;
if ((opdope[t->op]&RELAT)!=0)
t = t->tr1;
if (t->type==FLOAT || t->type==DOUBLE) {
nfloat = 1;
return('f');
}
return(0);
}
oddreg(t, areg)
struct tnode *t;
{
register reg;
reg = areg;
if (!isfloat(t)) {
if (opdope[t->op]&RELAT) {
if (t->tr1->type==LONG)
return((reg+1) & ~01);
return(reg);
}
switch(t->op) {
case LLSHIFT:
case ASLSHL:
return((reg+1)&~01);
case DIVIDE:
case MOD:
case ASDIV:
case ASMOD:
case PTOI:
case ULSH:
case ASULSH:
reg++;
case TIMES:
case ASTIMES:
return(reg|1);
}
}
return(reg);
}
arlength(t)
{
if (t>=PTR)
return(2);
switch(t) {
case INT:
case CHAR:
case UNSIGN:
return(2);
case LONG:
return(4);
case FLOAT:
case DOUBLE:
return(8);
}
return(1024);
}
/*
* Strings for switch code.
*/
char dirsw[] {"\
cmp r0,$%o\n\
jhi L%d\n\
asl r0\n\
jmp *L%d(r0)\n\
.data\n\
L%d:\
" };
char hashsw[] {"\
mov r0,r1\n\
clr r0\n\
div $%o,r0\n\
asl r1\n\
jmp *L%d(r1)\n\
.data\n\
L%d:\
"};
/*
* If the unsigned casts below won't compile,
* try using the calls to lrem and ldiv.
*/
pswitch(afp, alp, deflab)
struct swtab *afp, *alp;
{
int ncase, i, j, tabs, worst, best, range;
register struct swtab *swp, *fp, *lp;
int *poctab;
fp = afp;
lp = alp;
if (fp==lp) {
printf("jbr L%d\n", deflab);
return;
}
isn++;
if (sort(fp, lp))
return;
ncase = lp-fp;
lp--;
range = lp->swval - fp->swval;
/* direct switch */
if (range>0 && range <= 3*ncase) {
if (fp->swval)
printf("sub $%o,r0\n", fp->swval);
printf(dirsw, range, deflab, isn, isn);
isn++;
for (i=fp->swval; ; i++) {
if (i==fp->swval) {
printf("L%d\n", fp->swlab);
if (fp==lp)
break;
fp++;
} else
printf("L%d\n", deflab);
}
printf(".text\n");
return;
}
/* simple switch */
if (ncase<10) {
for (fp = afp; fp<=lp; fp++)
breq(fp->swval, fp->swlab);
printf("jbr L%d\n", deflab);
return;
}
/* hash switch */
best = 077777;
poctab = getblk(((ncase+2)/2) * sizeof(*poctab));
for (i=ncase/4; i<=ncase/2; i++) {
for (j=0; j<i; j++)
poctab[j] = 0;
for (swp=fp; swp<=lp; swp++)
/* lrem(0, swp->swval, i) */
poctab[(unsigned)swp->swval%i]++;
worst = 0;
for (j=0; j<i; j++)
if (poctab[j]>worst)
worst = poctab[j];
if (i*worst < best) {
tabs = i;
best = i*worst;
}
}
i = isn++;
printf(hashsw, tabs, i, i);
isn++;
for (i=0; i<tabs; i++)
printf("L%d\n", isn+i);
printf(".text\n");
for (i=0; i<tabs; i++) {
printf("L%d:", isn++);
for (swp=fp; swp<=lp; swp++) {
/* lrem(0, swp->swval, tabs) */
if ((unsigned)swp->swval%tabs == i) {
/* ldiv(0, swp->swval, tabs) */
breq((unsigned)swp->swval/tabs, swp->swlab);
}
}
printf("jbr L%d\n", deflab);
}
}
breq(v, l)
{
if (v==0)
printf("tst r0\n");
else
printf("cmp r0,$%o\n", v);
printf("jeq L%d\n", l);
}
sort(afp, alp)
struct swtab *afp, *alp;
{
register struct swtab *cp, *fp, *lp;
int intch, t;
fp = afp;
lp = alp;
while (fp < --lp) {
intch = 0;
for (cp=fp; cp<lp; cp++) {
if (cp->swval == cp[1].swval) {
error("Duplicate case (%d)", cp->swval);
return(1);
}
if (cp->swval > cp[1].swval) {
intch++;
t = cp->swval;
cp->swval = cp[1].swval;
cp[1].swval = t;
t = cp->swlab;
cp->swlab = cp[1].swlab;
cp[1].swlab = t;
}
}
if (intch==0)
break;
}
return(0);
}
ispow2(atree)
{
register int d;
register struct tnode *tree;
tree = atree;
if (!isfloat(tree) && tree->tr2->op==CON) {
d = tree->tr2->value;
if (d>1 && (d&(d-1))==0)
return(d);
}
return(0);
}
pow2(atree)
struct tnode *atree;
{
register int d, i;
register struct tnode *tree;
tree = atree;
if (d = ispow2(tree)) {
for (i=0; (d=>>1)!=0; i++);
tree->tr2->value = i;
switch (tree->op) {
case TIMES:
tree->op = LSHIFT;
break;
case ASTIMES:
tree->op = ASLSH;
break;
case DIVIDE:
tree->op = ULSH;
tree->tr2->value = -i;
break;
case ASDIV:
tree->op = ASULSH;
tree->tr2->value = -i;
break;
case MOD:
tree->op = AND;
tree->tr2->value = (1<<i)-1;
break;
case ASMOD:
tree->op = ASAND;
tree->tr2->value = (1<<i)-1;
break;
default:
error("pow2 botch");
}
tree = optim(tree);
}
return(tree);
}
cbranch(atree, albl, cond, areg)
struct tnode *atree;
{
int l1, op;
register lbl, reg;
register struct tnode *tree;
lbl = albl;
reg = areg;
again:
if ((tree=atree)==0)
return;
switch(tree->op) {
case LOGAND:
if (cond) {
cbranch(tree->tr1, l1=isn++, 0, reg);
cbranch(tree->tr2, lbl, 1, reg);
label(l1);
} else {
cbranch(tree->tr1, lbl, 0, reg);
cbranch(tree->tr2, lbl, 0, reg);
}
return;
case LOGOR:
if (cond) {
cbranch(tree->tr1, lbl, 1, reg);
cbranch(tree->tr2, lbl, 1, reg);
} else {
cbranch(tree->tr1, l1=isn++, 1, reg);
cbranch(tree->tr2, lbl, 0, reg);
label(l1);
}
return;
case EXCLA:
cbranch(tree->tr1, lbl, !cond, reg);
return;
case SEQNC:
rcexpr(tree->tr1, efftab, reg);
atree = tree->tr2;
goto again;
case ITOL:
tree = tree->tr1;
break;
}
op = tree->op;
if (opdope[op]&RELAT
&& tree->tr1->op==ITOL && tree->tr2->op==ITOL) {
tree->tr1 = tree->tr1->tr1;
tree->tr2 = tree->tr2->tr1;
if (op>=LESSEQ && op<=GREAT
&& (tree->tr1->type==UNSIGN || tree->tr2->type==UNSIGN))
tree->op = op = op+LESSEQP-LESSEQ;
}
if (tree->type==LONG
|| opdope[op]&RELAT&&tree->tr1->type==LONG) {
longrel(tree, lbl, cond, reg);
return;
}
rcexpr(tree, cctab, reg);
op = tree->op;
if ((opdope[op]&RELAT)==0)
op = NEQUAL;
else {
l1 = tree->tr2->op;
if ((l1==CON || l1==SFCON) && tree->tr2->value==0)
op =+ 200; /* special for ptr tests */
else
op = maprel[op-EQUAL];
}
if (isfloat(tree))
printf("cfcc\n");
branch(lbl, op, !cond);
}
branch(lbl, aop, c)
{
register op;
if(op=aop)
prins(op, c, branchtab);
else
printf("jbr");
printf("\tL%d\n", lbl);
}
longrel(atree, lbl, cond, reg)
struct tnode *atree;
{
int xl1, xl2, xo, xz;
register int op, isrel;
register struct tnode *tree;
if (reg&01)
reg++;
reorder(&atree, cctab, reg);
tree = atree;
isrel = 0;
if (opdope[tree->op]&RELAT) {
isrel++;
op = tree->op;
} else
op = NEQUAL;
if (!cond)
op = notrel[op-EQUAL];
xl1 = xlab1;
xl2 = xlab2;
xo = xop;
xlab1 = lbl;
xlab2 = 0;
xop = op;
xz = xzero;
xzero = !isrel || tree->tr2->op==ITOL && tree->tr2->tr1->op==CON
&& tree->tr2->tr1->value==0;
if (tree->op==ANDN) {
tree->op = TAND;
tree->tr2 = optim(tnode(COMPL, LONG, tree->tr2));
}
if (cexpr(tree, cctab, reg) < 0) {
reg = rcexpr(tree, regtab, reg);
printf("ashc $0,r%d\n", reg);
branch(xlab1, op, 0);
}
xlab1 = xl1;
xlab2 = xl2;
xop = xo;
xzero = xz;
}
/*
* Tables for finding out how best to do long comparisons.
* First dimen is whether or not the comparison is with 0.
* Second is which test: e.g. a>b->
* cmp a,b
* bgt YES (first)
* blt NO (second)
* cmp a+2,b+2
* bhi YES (third)
* NO: ...
* Note some tests may not be needed.
*/
char lrtab[2][3][6] {
0, NEQUAL, LESS, LESS, GREAT, GREAT,
NEQUAL, 0, GREAT, GREAT, LESS, LESS,
EQUAL, NEQUAL, LESSEQP,LESSP, GREATQP,GREATP,
0, NEQUAL, LESS, LESS, GREATEQ,GREAT,
NEQUAL, 0, GREAT, 0, 0, LESS,
EQUAL, NEQUAL, EQUAL, 0, 0, NEQUAL,
};
xlongrel(f)
{
register int op, bno;
op = xop;
if (f==0) {
if (bno = lrtab[xzero][0][op-EQUAL])
branch(xlab1, bno, 0);
if (bno = lrtab[xzero][1][op-EQUAL]) {
xlab2 = isn++;
branch(xlab2, bno, 0);
}
if (lrtab[xzero][2][op-EQUAL]==0)
return(1);
} else {
branch(xlab1, lrtab[xzero][2][op-EQUAL], 0);
if (xlab2)
label(xlab2);
}
return(0);
}
label(l)
{
printf("L%d:", l);
}
popstk(a)
{
switch(a) {
case 0:
return;
case 2:
printf("tst (sp)+\n");
return;
case 4:
printf("cmp (sp)+,(sp)+\n");
return;
}
printf("add $%o,sp\n", a);
}
error(s, p1, p2, p3, p4, p5, p6)
{
nerror++;
fprintf(stderr, "%d: ", line);
fprintf(stderr, s, p1, p2, p3, p4, p5, p6);
putc('\n', stderr);
}
psoct(an)
{
register int n, sign;
sign = 0;
if ((n = an) < 0) {
n = -n;
sign = '-';
}
printf("%c%o", sign, n);
}
/*
* Read in an intermediate file.
*/
#define STKS 100
getree()
{
struct tnode *expstack[STKS];
register struct tnode **sp;
register t, op;
static char s[9];
struct swtab *swp;
double atof();
char numbuf[64];
struct tname *np;
struct xtname *xnp;
struct ftconst *fp;
struct lconst *lp;
struct fasgn *sap;
int lbl, cond, lbl2, lbl3;
curbase = funcbase;
sp = expstack;
for (;;) {
if (sp >= &expstack[STKS])
error("Stack overflow botch");
op = geti();
if ((op&0177400) != 0177000) {
error("Intermediate file error");
exit(1);
}
lbl = 0;
switch(op =& 0377) {
case SINIT:
printf("%o\n", geti());
break;
case EOFC:
return;
case BDATA:
if (geti() == 1) {
printf(".byte ");
for (;;) {
printf("%o", geti());
if (geti() != 1)
break;
printf(",");
}
printf("\n");
}
break;
case PROG:
printf(".text\n");
break;
case DATA:
printf(".data\n");
break;
case BSS:
printf(".bss\n");
break;
case SYMDEF:
outname(s);
printf(".globl%s%.8s\n", s[0]?" ":"", s);
sfuncr.nloc = 0;
break;
case RETRN:
printf("jmp cret\n");
break;
case CSPACE:
t = outname(s);
printf(".comm %.8s,%o\n", t, geti());
break;
case SSPACE:
printf(".=.+%o\n", (t=geti()));
totspace += (unsigned)t;
break;
case EVEN:
printf(".even\n");
break;
case SAVE:
printf("jsr r5,csv\n");
break;
case SETSTK:
/*
* fix: Bill Shannon 4/17/80
* size of stack frame is subtracted off
* in first pass, instead of here.
* c02.c also changed.
*/
t = geti() /* -6 */ ;
if (t==2)
printf("tst -(sp)\n");
else if (t != 0)
printf("sub $%o,sp\n", t);
break;
case PROFIL:
t = geti();
printf("mov $L%d,r0\njsr pc,mcount\n", t);
printf(".bss\nL%d:.=.+2\n.text\n", t);
break;
case SNAME:
t = outname(s);
printf("~%s=L%d\n", t+1, geti());
break;
case ANAME:
t = outname(s);
printf("~%s=%o\n", t+1, geti());
break;
case RNAME:
t = outname(s);
printf("~%s=r%d\n", t+1, geti());
break;
case SWIT:
t = geti();
line = geti();
curbase = funcbase;
while(swp=getblk(sizeof(*swp)), swp->swlab = geti())
swp->swval = geti();
pswitch(funcbase, swp, t);
break;
case C3BRANCH: /* for fortran [sic] */
lbl = geti();
lbl2 = geti();
lbl3 = geti();
goto xpr;
case CBRANCH:
lbl = geti();
cond = geti();
case EXPR:
xpr:
line = geti();
if (sp != &expstack[1]) {
error("Expression input botch");
exit(1);
}
nstack = 0;
*sp = optim(*--sp);
if (op==CBRANCH)
cbranch(*sp, lbl, cond, 0);
else if (op==EXPR)
rcexpr(*sp, efftab, 0);
else {
if ((*sp)->type==LONG) {
rcexpr(tnode(RFORCE, (*sp)->type, *sp), efftab, 0);
printf("ashc $0,r0\n");
} else {
rcexpr(*sp, cctab, 0);
if (isfloat(*sp))
printf("cfcc\n");
}
printf("jgt L%d\n", lbl3);
printf("jlt L%d\njbr L%d\n", lbl, lbl2);
}
curbase = funcbase;
break;
case NAME:
t = geti();
if (t==EXTERN) {
np = getblk(sizeof(*xnp));
np->type = geti();
outname(np->name);
} else {
np = getblk(sizeof(*np));
np->type = geti();
np->nloc = geti();
}
np->op = NAME;
np->class = t;
np->regno = 0;
np->offset = 0;
*sp++ = np;
break;
case CON:
t = geti();
*sp++ = tconst(geti(), t);
break;
case LCON:
geti(); /* ignore type, assume long */
t = geti();
op = geti();
if (t==0 && op>=0 || t == -1 && op<0) {
*sp++ = tnode(ITOL, LONG, tconst(op, INT));
break;
}
lp = getblk(sizeof(*lp));
lp->op = LCON;
lp->type = LONG;
lp->lvalue = ((long)t<<16) + (unsigned)op; /* nonportable */
*sp++ = lp;
break;
case FCON:
t = geti();
outname(numbuf);
fp = getblk(sizeof(*fp));
fp->op = FCON;
fp->type = t;
fp->value = isn++;
fp->fvalue = atof(numbuf);
*sp++ = fp;
break;
case FSEL:
*sp = tnode(FSEL, geti(), *--sp, NULL);
t = geti();
(*sp++)->tr2 = tnode(COMMA, INT, tconst(geti(), INT), tconst(t, INT));
break;
case STRASG:
sap = getblk(sizeof(*sap));
sap->op = STRASG;
sap->type = geti();
sap->mask = geti();
sap->tr1 = *--sp;
sap->tr2 = NULL;
*sp++ = sap;
break;
case NULLOP:
*sp++ = tnode(0, 0, NULL, NULL);
break;
case LABEL:
label(geti());
break;
case NLABEL:
t = outname(s);
printf("%.8s:\n", t, t);
break;
case RLABEL:
t = outname(s);
printf("%.8s:\n~~%s:\n", t, t+1);
break;
case BRANCH:
branch(geti(), 0);
break;
case SETREG:
nreg = geti()-1;
break;
default:
if (opdope[op]&BINARY) {
if (sp < &expstack[1]) {
error("Binary expression botch");
exit(1);
}
t = *--sp;
*sp++ = tnode(op, geti(), *--sp, t);
} else
sp[-1] = tnode(op, geti(), sp[-1]);
break;
}
}
}
geti()
{
register i;
i = getchar();
i += getchar()<<8;
return(i);
}
outname(s)
{
register char *p, c;
register n;
p = s;
n = 0;
while (c = getchar()) {
*p++ = c;
n++;
}
do {
*p++ = 0;
} while (n++ < 8);
return(s);
}
strasg(atp)
struct fasgn *atp;
{
register struct tnode *tp;
register nwords, i;
nwords = atp->mask/sizeof(int);
tp = atp->tr1;
if (tp->op != ASSIGN) {
if (tp->op==RFORCE) { /* function return */
if (sfuncr.nloc==0) {
sfuncr.nloc = isn++;
printf(".bss\nL%d:.=.+%o\n.text\n", sfuncr.nloc, nwords*sizeof(int));
}
atp->tr1 = tnode(ASSIGN, STRUCT, &sfuncr, tp->tr1);
strasg(atp);
printf("mov $L%d,r0\n", sfuncr.nloc);
return;
}
if (tp->op==CALL) {
rcexpr(tp, efftab, 0);
return;
}
error("Illegal structure operation");
return;
}
tp->tr2 = strfunc(tp->tr2);
if (nwords==1)
setype(tp, INT);
else if (nwords==sizeof(int))
setype(tp, LONG);
else {
if (tp->tr1->op!=NAME && tp->tr1->op!=STAR
|| tp->tr2->op!=NAME && tp->tr2->op!=STAR) {
error("unimplemented structure assignment");
return;
}
tp->tr1 = tnode(AMPER, STRUCT+PTR, tp->tr1);
tp->tr2 = tnode(AMPER, STRUCT+PTR, tp->tr2);
tp->op = STRSET;
tp->type = STRUCT+PTR;
tp = optim(tp);
rcexpr(tp, efftab, 0);
if (nwords < 7) {
for (i=0; i<nwords; i++)
printf("mov (r1)+,(r0)+\n");
return;
}
if (nreg<=1)
printf("mov r2,-(sp)\n");
printf("mov $%o,r2\n", nwords);
printf("L%d:mov (r1)+,(r0)+\ndec\tr2\njne\tL%d\n", isn, isn);
isn++;
if (nreg<=1)
printf("mov (sp)+,r2\n");
return;
}
rcexpr(tp, efftab, 0);
}
setype(p, t)
register struct tnode *p;
register t;
{
for (;; p = p->tr1) {
p->type = t;
if (p->op==AMPER)
t = decref(t);
else if (p->op==STAR)
t = incref(t);
else if (p->op==ASSIGN)
setype(p->tr2, t);
else if (p->op!=PLUS)
break;
}
}
/*
* Reduce the degree-of-reference by one.
* e.g. turn "ptr-to-int" into "int".
*/
decref(at)
{
register t;
t = at;
if ((t & ~TYPE) == 0) {
error("Illegal indirection");
return(t);
}
return((t>>TYLEN) & ~TYPE | t&TYPE);
}
/*
* Increase the degree of reference by
* one; e.g. turn "int" to "ptr-to-int".
*/
incref(t)
{
return(((t&~TYPE)<<TYLEN) | (t&TYPE) | PTR);
}