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Research V6 development
[unix-history] / usr / source / c / c11.c
#
/*
* C compiler
*/
#include "c1h.c"
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 && (t1 = isconstant(t)) && t1->value>= 0)
return(-2);
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;
p = ap;
loop:
switch(p->op) {
case SFCON:
case CON:
printf("$");
psoct(p->value);
return;
case FCON:
printf("L%d", p->value);
return;
case NAME:
i = p->offset;
if (flag==2)
i =+ 2;
if (i) {
psoct(i);
if (p->class!=OFFS)
putchar('+');
if (p->class==REG)
regerr();
}
switch(p->class) {
case SOFFS:
case XOFFS:
pbase(p);
case OFFS:
printf("(r%d)", p->regno);
return;
case EXTERN:
case STATIC:
pbase(p);
return;
case REG:
printf("r%d", p->nloc);
return;
}
error("Compiler error: pname");
return;
case AMPER:
putchar('$');
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==1?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 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<PTR);
if (st==1) /* word */
return(at>INT && at<PTR);
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)
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))
switch(t->op) {
case DIVIDE:
case MOD:
case ASDIV:
case ASMOD:
reg++;
case TIMES:
case ASTIMES:
return(reg|1);
}
return(reg);
}
arlength(t)
{
if (t>=PTR)
return(2);
switch(t) {
case INT:
case CHAR:
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 simpsw[] {"\
mov $L%d,r1\n\
mov r0,L%d\n\
L%d:cmp r0,(r1)+\n\
jne L%d\n\
jmp *L%d-L%d(r1)\n\
.data\n\
L%d:\
"};
char hashsw[] {"\
mov r0,r1\n\
clr r0\n\
div $%o,r0\n\
asl r1\n\
add $L%d,r1\n\
mov r0,*(r1)+\n\
mov (r1)+,r1\n\
L%d:cmp r0,-(r1)\n\
jne L%d\n\
jmp *L%d-L%d(r1)\n\
.data\n\
L%d:\
"};
pswitch(afp, alp, deflab)
struct swtab *afp, *alp;
{
int tlab, ncase, i, j, tabs, worst, best, range;
register struct swtab *swp, *fp, *lp;
int poctab[swsiz];
fp = afp;
lp = alp;
if (fp==lp) {
printf("jbr L%d\n", deflab);
return;
}
tlab = 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<=lp->swval; i++) {
if (i==fp->swval) {
printf("L%d\n", fp->swlab);
fp++;
} else
printf("L%d\n", deflab);
}
goto esw;
}
/* simple switch */
if (ncase<8) {
i = isn++;
j = isn++;
printf(simpsw, i, j, isn, isn, j, i, i);
isn++;
for (; fp<=lp; fp++)
printf("%o\n", fp->swval);
printf("L%d:..\n", j);
for (fp = afp; fp<=lp; fp++)
printf("L%d\n", fp->swlab);
printf("L%d\n", deflab);
goto esw;
}
/* hash switch */
best = 077777;
for (i=ncase/4; i<=ncase/2; i++) {
for (j=0; j<i; j++)
poctab[j] = 0;
for (swp=fp; swp<=lp; swp++)
poctab[lrem(0, 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, isn, i, i, isn+tabs+1, isn+1, isn);
isn++;
for (i=0; i<=tabs; i++)
printf("L%d\n", isn+i);
for (i=0; i<tabs; i++) {
printf("L%d:..\n", isn++);
for (swp=fp; swp<=lp; swp++)
if (lrem(0, swp->swval, tabs) == i)
printf("%o\n", ldiv(0, swp->swval, tabs));
}
printf("L%d:", isn++);
for (i=0; i<tabs; i++) {
printf("L%d\n", deflab);
for (swp=fp; swp<=lp; swp++)
if (lrem(0, swp->swval, tabs) == i)
printf("L%d\n", swp->swlab);
}
esw:
printf(".text\n");
}
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;
d = tree->op;
tree->op = d==TIMES? LSHIFT:
(d==DIVIDE? RSHIFT:
(d==ASTIMES? ASLSH: ASRSH));
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;
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 COMMA:
rcexpr(tree->tr1, efftab, reg);
tree = tree->tr2;
break;
}
op = tree->op;
if (tree->type==LONG || opdope[op]&RELAT&&tree->tr1->type==LONG) {
if (tree->type!=LONG) {
tree->op = MINUS;
tree->type = LONG;
tree = optim(tree);
} else
op = NEQUAL;
rcexpr(tree, regtab, 0);
printf("ashc $0,r0\n");
branch(lbl, op, !cond);
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);
}
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)
{
register f;
extern fout;
nerror++;
flush();
f = fout;
fout = 1;
printf("%d: ", line);
printf(s, p1, p2, p3, p4, p5, p6);
putchar('\n');
flush();
fout = f;
}
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.
*/
getree()
{
struct tnode *expstack[20];
register struct tnode **sp;
register t, op;
static char s[9];
struct swtab *swp;
spacep = treespace;
sp = expstack;
for (;;) {
if (sp >= &expstack[20])
error("Stack botch");
op = getw(ascbuf);
if ((op&0177400) != 0177000) {
error("Intermediate file error");
exit(1);
}
switch(op =& 0377) {
case EOF:
return;
case BDATA:
printf(".byte ");
seq(',');
break;
case WDATA:
seq(';');
break;
case PROG:
printf(".text\n");
break;
case DATA:
printf(".data\n");
break;
case BSS:
printf(".bss\n");
break;
case SYMDEF:
printf(".globl _%s\n", outname(s));
break;
case RETRN:
printf("jmp cret\n");
break;
case CSPACE:
t = outname(s);
printf(".comm _%s,%o\n", t, getw(ascbuf));
break;
case SSPACE:
printf(".=.+%o\n", getw(ascbuf));
break;
case EVEN:
printf(".even\n");
break;
case SAVE:
printf("jsr r5,csv\n");
t = getw(ascbuf)-6;
if (t==2)
printf("tst -(sp)\n");
else if (t > 2)
printf("sub $%o,sp\n", t);
break;
case PROFIL:
t = getw(ascbuf);
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, getw(ascbuf));
break;
case ANAME:
t = outname(s);
printf("~%s=%o\n", t, getw(ascbuf));
break;
case RNAME:
t = outname(s);
printf("~%s=r%d\n", t, getw(ascbuf));
break;
case SWIT:
t = getw(ascbuf);
line = getw(ascbuf);
swp = treespace;
while (swp->swlab = getw(ascbuf)) {
swp->swval = getw(ascbuf);
swp++;
}
pswitch(treespace, swp, t);
break;
case EXPR:
line = getw(ascbuf);
if (sp != &expstack[1]) {
error("Expression input botch\n");
exit(1);
}
nstack = 0;
rcexpr(optim(*--sp), efftab, 0);
spacep = treespace;
break;
case NAME:
t = getw(ascbuf);
if (t==EXTERN) {
t = getw(ascbuf);
*sp = block(6, NAME, t, 0, EXTERN, 0, 0,0,0,0);
outname(&(*sp)->nloc);
sp++;
break;
}
*sp = block(3, NAME, 0, 0, t, 0, 0);
(*sp)->type = getw(ascbuf);
(*sp)->nloc = getw(ascbuf);
sp++;
break;
case CON:
case SFCON:
case FCON:
t = getw(ascbuf);
*sp++ = block(1, op, t, 0, getw(ascbuf));
break;
case FSEL:
t = getw(ascbuf);
sp[-1] = block(2, op, t, 0, sp[-1], getw(ascbuf));
break;
case NULL:
*sp++ = block(0, 0, 0, 0);
break;
case CBRANCH:
t = getw(ascbuf);
sp[-1] = block(1, CBRANCH, sp[-1], t, getw(ascbuf));
break;
case LABEL:
label(getw(ascbuf));
break;
case NLABEL:
printf("_%s:\n", outname(s));
break;
case RLABEL:
t = outname(s);
printf("_%s:\n~~%s:\n", t, t);
break;
case BRANCH:
branch(getw(ascbuf), 0);
break;
case SETREG:
nreg = getw(ascbuf)-1;
break;
default:
if (opdope[op]&BINARY) {
if (sp < &expstack[1]) {
error("Binary expression botch");
exit(1);
}
t = *--sp;
*sp++ = block(2, op, getw(ascbuf), 0, *--sp, t);
} else {
sp[-1] = block(1, op, getw(ascbuf), 0, sp[-1]);
}
break;
}
}
}
outname(s)
{
register char *p, c;
register n;
p = s;
n = 0;
while (c = getc(ascbuf)) {
*p++ = c;
n++;
}
while (n++ < 8)
*p++ = 0;
return(s);
}
seq(c)
{
register o;
if (getw(ascbuf) == 0)
return;
for (;;) {
printf("%o", getw(ascbuf));
if ((o = getw(ascbuf)) != 1)
break;
printf("%c", c);
}
printf("\n");
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.