import tc and tl from 9ferno

1 files changed, 942 insertions, 0 deletions

diff --git a/sys/src/cmd/tl/pass.c b/sys/src/cmd/tl/pass.c
new file mode 100644
index 000000000..e4322df5c
--- /dev/null
+++ b/sys/src/cmd/tl/pass.c
@@ -0,0 +1,942 @@
+#include	"l.h"
+
+void
+dodata(void)
+{
+	int i, t;
+	Sym *s;
+	Prog *p;
+	long orig, v;
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f dodata\n", cputime());
+	Bflush(&bso);
+	for(p = datap; p != P; p = p->link) {
+		s = p->from.sym;
+		if(p->as == ADYNT || p->as == AINIT)
+			s->value = dtype;
+		if(s->type == SBSS)
+			s->type = SDATA;
+		if(s->type != SDATA)
+			diag("initialize non-data (%d): %s\n%P",
+				s->type, s->name, p);
+		v = p->from.offset + p->reg;
+		if(v > s->value)
+			diag("initialize bounds (%ld): %s\n%P",
+				s->value, s->name, p);
+		if((s->type == SBSS || s->type == SDATA) && (p->to.type == D_CONST || p->to.type == D_OCONST) && (p->to.name == D_EXTERN || p->to.name == D_STATIC)){
+			s = p->to.sym;
+			if(s != S && (s->type == STEXT || s->type == SLEAF || s->type == SCONST || s->type == SXREF))
+				s->fnptr = 1;
+		}
+	}
+
+	if(debug['t']) {
+		/*
+		 * pull out string constants
+		 */
+		for(p = datap; p != P; p = p->link) {
+			s = p->from.sym;
+			if(p->to.type == D_SCONST)
+				s->type = SSTRING;
+		}
+	}
+
+	/*
+	 * pass 1
+	 *	assign 'small' variables to data segment
+	 *	(rational is that data segment is more easily
+	 *	 addressed through offset on R12)
+	 */
+	orig = 0;
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		t = s->type;
+		if(t != SDATA && t != SBSS)
+			continue;
+		v = s->value;
+		if(v == 0) {
+			diag("%s: no size", s->name);
+			v = 1;
+		}
+		while(v & 3)
+			v++;
+		s->value = v;
+		if(v > MINSIZ)
+			continue;
+		s->value = orig;
+		orig += v;
+		s->type = SDATA1;
+	}
+
+	/*
+	 * pass 2
+	 *	assign large 'data' variables to data segment
+	 */
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		t = s->type;
+		if(t != SDATA) {
+			if(t == SDATA1)
+				s->type = SDATA;
+			continue;
+		}
+		v = s->value;
+		s->value = orig;
+		orig += v;
+	}
+
+	while(orig & 7)
+		orig++;
+	datsize = orig;
+
+	/*
+	 * pass 3
+	 *	everything else to bss segment
+	 */
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		if(s->type != SBSS)
+			continue;
+		v = s->value;
+		s->value = orig;
+		orig += v;
+	}
+	while(orig & 7)
+		orig++;
+	bsssize = orig-datsize;
+
+	xdefine("setR12", SDATA, 0L+BIG);
+	xdefine("bdata", SDATA, 0L);
+	xdefine("edata", SDATA, datsize);
+	xdefine("end", SBSS, datsize+bsssize);
+	xdefine("etext", STEXT, 0L);
+}
+
+void
+undef(void)
+{
+	int i;
+	Sym *s;
+
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link)
+		if(s->type == SXREF)
+			diag("%s: not defined", s->name);
+}
+
+Prog*
+brchain(Prog *p)
+{
+	int i;
+
+	for(i=0; i<20; i++) {
+		if(p == P || p->as != AB)
+			return p;
+		p = p->cond;
+	}
+	return P;
+}
+
+int
+relinv(int a)
+{
+	switch(a) {
+	case ABEQ:	return ABNE;
+	case ABNE:	return ABEQ;
+	case ABCS:	return ABCC;
+	case ABHS:	return ABLO;
+	case ABCC:	return ABCS;
+	case ABLO:	return ABHS;
+	case ABMI:	return ABPL;
+	case ABPL:	return ABMI;
+	case ABVS:	return ABVC;
+	case ABVC:	return ABVS;
+	case ABHI:	return ABLS;
+	case ABLS:	return ABHI;
+	case ABGE:	return ABLT;
+	case ABLT:	return ABGE;
+	case ABGT:	return ABLE;
+	case ABLE:	return ABGT;
+	}
+	diag("unknown relation: %s", anames[a]);
+	return a;
+}
+
+void
+follow(void)
+{
+	if(debug['v'])
+		Bprint(&bso, "%5.2f follow\n", cputime());
+	Bflush(&bso);
+
+	firstp = prg();
+	lastp = firstp;
+	xfol(textp);
+
+	firstp = firstp->link;
+	lastp->link = P;
+}
+
+void
+xfol(Prog *p)
+{
+	Prog *q, *r;
+	int a, i;
+
+loop:
+	if(p == P)
+		return;
+	setarch(p);
+	a = p->as;
+	if(a == ATEXT)
+		curtext = p;
+	if(a == AB) {
+		q = p->cond;
+		if(q != P) {
+			p->mark |= FOLL;
+			p = q;
+			if(!(p->mark & FOLL))
+				goto loop;
+		}
+	}
+	if(p->mark & FOLL) {
+		for(i=0,q=p; i<4; i++,q=q->link) {
+			if(q == lastp)
+				break;
+			a = q->as;
+			if(a == ANOP) {
+				i--;
+				continue;
+			}
+			if(a == AB || (a == ARET && q->scond == 14) || a == ARFE)
+				goto copy;
+			if(!q->cond || (q->cond->mark&FOLL))
+				continue;
+			if(a != ABEQ && a != ABNE)
+				continue;
+		copy:
+			for(;;) {
+				r = prg();
+				*r = *p;
+				if(!(r->mark&FOLL))
+					print("cant happen 1\n");
+				r->mark |= FOLL;
+				if(p != q) {
+					p = p->link;
+					lastp->link = r;
+					lastp = r;
+					continue;
+				}
+				lastp->link = r;
+				lastp = r;
+				if(a == AB || (a == ARET && q->scond == 14) || a == ARFE)
+					return;
+				r->as = ABNE;
+				if(a == ABNE)
+					r->as = ABEQ;
+				r->cond = p->link;
+				r->link = p->cond;
+				if(!(r->link->mark&FOLL))
+					xfol(r->link);
+				if(!(r->cond->mark&FOLL))
+					print("cant happen 2\n");
+				return;
+			}
+		}
+		a = AB;
+		q = prg();
+		q->as = a;
+		q->line = p->line;
+		q->to.type = D_BRANCH;
+		q->to.offset = p->pc;
+		q->cond = p;
+		p = q;
+	}
+	p->mark |= FOLL;
+	lastp->link = p;
+	lastp = p;
+	if(a == AB || (a == ARET && p->scond == 14) || a == ARFE){
+		return;
+	}
+	if(p->cond != P)
+	if(a != ABL && a != ABX && p->link != P) {
+		q = brchain(p->link);
+		if(a != ATEXT && a != ABCASE)
+		if(q != P && (q->mark&FOLL)) {
+			p->as = relinv(a);
+			p->link = p->cond;
+			p->cond = q;
+		}
+		xfol(p->link);
+		q = brchain(p->cond);
+		if(q == P)
+			q = p->cond;
+		if(q->mark&FOLL) {
+			p->cond = q;
+			return;
+		}
+		p = q;
+		goto loop;
+	}
+	p = p->link;
+	goto loop;
+}
+
+void
+patch(void)
+{
+	long c, vexit;
+	Prog *p, *q;
+	Sym *s, *s1;
+	int a;
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f patch\n", cputime());
+	Bflush(&bso);
+	mkfwd();
+	s = lookup("exit", 0);
+	vexit = s->value;
+	for(p = firstp; p != P; p = p->link) {
+		setarch(p);
+		a = p->as;
+		if(a == ATEXT)
+			curtext = p;
+		if(seenthumb && a == ABL){
+			// if((s = p->to.sym) != S && (s1 = curtext->from.sym) != S)
+			//	print("%s calls %s\n", s1->name, s->name);
+			 if((s = p->to.sym) != S && (s1 = curtext->from.sym) != S && s->thumb != s1->thumb)
+				s->foreign = 1;
+		}
+		if((a == ABL || a == ABX || a == AB || a == ARET) &&
+		   p->to.type != D_BRANCH && p->to.sym != S) {
+			s = p->to.sym;
+			switch(s->type) {
+			default:
+				diag("undefined: %s\n%P", s->name, p);
+				s->type = STEXT;
+				s->value = vexit;
+				break;
+			case STEXT:
+				p->to.offset = s->value;
+				p->to.type = D_BRANCH;
+				break;
+			case SUNDEF:
+				if(p->as != ABL)
+					diag("help: SUNDEF in AB || ARET");
+				p->to.offset = 0;
+				p->to.type = D_BRANCH;
+				p->cond = UP;
+				break;
+			}
+		}
+		if(p->to.type != D_BRANCH || p->cond == UP)
+			continue;
+		c = p->to.offset;
+		for(q = firstp; q != P;) {
+			if(q->forwd != P)
+			if(c >= q->forwd->pc) {
+				q = q->forwd;
+				continue;
+			}
+			if(c == q->pc)
+				break;
+			q = q->link;
+		}
+		if(q == P) {
+			diag("branch out of range %ld\n%P", c, p);
+			p->to.type = D_NONE;
+		}
+		p->cond = q;
+	}
+
+	for(p = firstp; p != P; p = p->link) {
+		setarch(p);
+		a = p->as;
+		if(p->as == ATEXT)
+			curtext = p;
+		if(seenthumb && a == ABL) {
+#ifdef CALLEEBX
+			if(0)
+				{}
+#else
+			if((s = p->to.sym) != S && (s->foreign || s->fnptr))
+				p->as = ABX;
+#endif
+			else if(p->to.type == D_OREG)
+				p->as = ABX;
+		}
+		if(p->cond != P && p->cond != UP) {
+			p->cond = brloop(p->cond);
+			if(p->cond != P)
+			if(p->to.type == D_BRANCH)
+				p->to.offset = p->cond->pc;
+		}
+	}
+}
+
+#define	LOG	5
+void
+mkfwd(void)
+{
+	Prog *p;
+	long dwn[LOG], cnt[LOG], i;
+	Prog *lst[LOG];
+
+	for(i=0; i<LOG; i++) {
+		if(i == 0)
+			cnt[i] = 1; else
+			cnt[i] = LOG * cnt[i-1];
+		dwn[i] = 1;
+		lst[i] = P;
+	}
+	i = 0;
+	for(p = firstp; p != P; p = p->link) {
+		if(p->as == ATEXT)
+			curtext = p;
+		i--;
+		if(i < 0)
+			i = LOG-1;
+		p->forwd = P;
+		dwn[i]--;
+		if(dwn[i] <= 0) {
+			dwn[i] = cnt[i];
+			if(lst[i] != P)
+				lst[i]->forwd = p;
+			lst[i] = p;
+		}
+	}
+}
+
+Prog*
+brloop(Prog *p)
+{
+	Prog *q;
+	int c;
+
+	for(c=0; p!=P;) {
+		if(p->as != AB)
+			return p;
+		q = p->cond;
+		if(q <= p) {
+			c++;
+			if(q == p || c > 5000)
+				break;
+		}
+		p = q;
+	}
+	return P;
+}
+
+long
+atolwhex(char *s)
+{
+	long n;
+	int f;
+
+	n = 0;
+	f = 0;
+	while(*s == ' ' || *s == '\t')
+		s++;
+	if(*s == '-' || *s == '+') {
+		if(*s++ == '-')
+			f = 1;
+		while(*s == ' ' || *s == '\t')
+			s++;
+	}
+	if(s[0]=='0' && s[1]){
+		if(s[1]=='x' || s[1]=='X'){
+			s += 2;
+			for(;;){
+				if(*s >= '0' && *s <= '9')
+					n = n*16 + *s++ - '0';
+				else if(*s >= 'a' && *s <= 'f')
+					n = n*16 + *s++ - 'a' + 10;
+				else if(*s >= 'A' && *s <= 'F')
+					n = n*16 + *s++ - 'A' + 10;
+				else
+					break;
+			}
+		} else
+			while(*s >= '0' && *s <= '7')
+				n = n*8 + *s++ - '0';
+	} else
+		while(*s >= '0' && *s <= '9')
+			n = n*10 + *s++ - '0';
+	if(f)
+		n = -n;
+	return n;
+}
+
+long
+rnd(long v, long r)
+{
+	long c;
+
+	if(r <= 0)
+		return v;
+	v += r - 1;
+	c = v % r;
+	if(c < 0)
+		c += r;
+	v -= c;
+	return v;
+}
+
+#define Reachable(n)	if((s = lookup(n, 0)) != nil) s->used++
+
+static void
+rused(Adr *a)
+{
+	Sym *s = a->sym;
+
+	if(s == S)
+		return;
+	if(a->type == D_OREG || a->type == D_OCONST || a->type == D_CONST){
+		if(a->name == D_EXTERN || a->name == D_STATIC){
+			if(s->used == 0)
+				s->used = 1;
+		}
+	}
+	else if(a->type == D_BRANCH){
+		if(s->used == 0)
+			s->used = 1;
+	}
+}
+
+void
+reachable()
+{
+	Prog *p, *prev, *prevt, *nextt, *q;
+	Sym *s, *s0;
+	int i, todo;
+	char *a;
+
+	Reachable("_div");
+	Reachable("_divu");
+	Reachable("_mod");
+	Reachable("_modu");
+	a = INITENTRY;
+	if(*a >= '0' && *a <= '9')
+		return;
+	s = lookup(a, 0);
+	if(s == nil)
+		return;
+	if(s->type == 0){
+		s->used = 1;	// to stop asm complaining
+		for(p = firstp; p != P && p->as != ATEXT; p = p->link)
+			;
+		if(p == nil)
+			return;
+		s = p->from.sym;
+	}	
+	s->used = 1;
+	do{
+		todo = 0;
+		for(p = firstp; p != P; p = p->link){
+			if(p->as == ATEXT && (s0 = p->from.sym)->used == 1){
+				todo = 1;
+				for(q = p->link; q != P && q->as != ATEXT; q = q->link){
+					rused(&q->from);
+					rused(&q->to);
+				}
+				s0->used = 2;
+			}
+		}
+		for(p = datap; p != P; p = p->link){
+			if((s0 = p->from.sym)->used == 1){
+				todo = 1;
+				for(q = p; q != P; q = q->link){	// data can be scattered
+					if(q->from.sym == s0)
+						rused(&q->to);
+				}
+				s0->used = 2;
+			}
+		}
+	}while(todo);
+	prev = nil;
+	prevt = nextt = nil;
+	for(p = firstp; p != P; ){
+		if(p->as == ATEXT){
+			prevt = nextt;
+			nextt = p;
+		}
+		if(p->as == ATEXT && (s0 = p->from.sym)->used == 0){
+			s0->type = SREMOVED;
+			for(q = p->link; q != P && q->as != ATEXT; q = q->link)
+				;
+			if(q != p->cond)
+				diag("bad ptr in reachable()");
+			if(prev == nil)
+				firstp = q;
+			else
+				prev->link = q;
+			if(q == nil)
+				lastp = prev;
+			if(prevt == nil)
+				textp = q;
+			else
+				prevt->cond = q;
+			if(q == nil)
+				etextp = prevt;
+			nextt = prevt;
+			if(debug['V'])
+				print("%s unused\n", s0->name);
+			p = q;
+		}
+		else{
+			prev = p;
+			p = p->link;
+		}
+	}
+	prevt = nil;
+	for(p = datap; p != nil; ){
+		if((s0 = p->from.sym)->used == 0){
+			s0->type = SREMOVED;
+			prev = prevt;
+			for(q = p; q != nil; q = q->link){
+				if(q->from.sym == s0){
+					if(prev == nil)
+						datap = q->link;
+					else
+						prev->link = q->link;
+				}
+				else
+					prev = q;
+			}
+			if(debug['V'])
+				print("%s unused (data)\n", s0->name);
+			p = prevt->link;
+		}
+		else{
+			prevt = p;
+			p = p->link;
+		}
+	}
+	for(i=0; i<NHASH; i++){
+		for(s = hash[i]; s != S; s = s->link){
+			if(s->used == 0)
+				s->type = SREMOVED;
+		}
+	}
+}
+
+static void
+fused(Adr *a, Prog *p, Prog *ct)
+{
+	Sym *s = a->sym;
+	Use *u;
+
+	if(s == S)
+		return;
+	if(a->type == D_OREG || a->type == D_OCONST || a->type == D_CONST){
+		if(a->name == D_EXTERN || a->name == D_STATIC){
+			u = malloc(sizeof(Use));
+			u->p = p;
+			u->ct = ct;
+			u->link = s->use;
+			s->use = u;
+		}
+	}
+	else if(a->type == D_BRANCH){
+		u = malloc(sizeof(Use));
+		u->p = p;
+		u->ct = ct;
+		u->link = s->use;
+		s->use = u;
+	}
+}
+
+static int
+ckfpuse(Prog *p, Prog *ct, Sym *fp, Sym *r)
+{
+	int reg;
+
+	USED(fp);
+	USED(ct);
+	if(p->from.sym == r && p->as == AMOVW && (p->from.type == D_CONST || p->from.type == D_OREG) && p->reg == NREG && p->to.type == D_REG){
+		reg = p->to.reg;
+		for(p = p->link; p != P && p->as != ATEXT; p = p->link){
+			if((p->as == ABL || p->as == ABX) && p->to.type == D_OREG && p->to.reg == reg)
+				return 1;
+			if(!debug['F'] && (isbranch(p) || p->as == ARET)){
+				// print("%s: branch %P in %s\n", fp->name, p, ct->from.sym->name);
+				return 0;
+			}
+			if((p->from.type == D_REG || p->from.type == D_OREG) && p->from.reg == reg){
+				if(!debug['F'] && p->to.type != D_REG){
+					// print("%s: store %P in %s\n", fp->name, p, ct->from.sym->name);
+					return 0;
+				}
+				reg = p->to.reg;
+			}
+		}
+	}
+	// print("%s: no MOVW O(R), R\n", fp->name);
+	return debug['F'];
+}
+
+static void
+setfpuse(Prog *p, Sym *fp, Sym *r)
+{
+	int reg;
+
+	if(p->from.sym == r && p->as == AMOVW && (p->from.type == D_CONST || p->from.type == D_OREG) && p->reg == NREG && p->to.type == D_REG){
+		reg = p->to.reg;
+		for(p = p->link; p != P && p->as != ATEXT; p = p->link){
+			if((p->as == ABL || p->as == ABX) && p->to.type == D_OREG && p->to.reg == reg){
+				fp->fnptr = 0;
+				p->as = ABL;	// safe to do so
+// print("simplified %s call\n", fp->name);
+				break;
+			}
+			if(!debug['F'] && (isbranch(p) || p->as == ARET))
+				diag("bad setfpuse call");
+			if((p->from.type == D_REG || p->from.type == D_OREG) && p->from.reg == reg){
+				if(!debug['F'] && p->to.type != D_REG)
+					diag("bad setfpuse call");
+				reg = p->to.reg;
+			}
+		}
+	}
+}
+
+static int
+cksymuse(Sym *s, int t)
+{
+	Prog *p;
+
+	for(p = datap; p != P; p = p->link){
+		if(p->from.sym == s && p->to.sym != nil && strcmp(p->to.sym->name, ".string") != 0 && p->to.sym->thumb != t){
+			// print("%s %s %d %d ", p->from.sym->name, p->to.sym->name, p->to.sym->thumb, t);
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/* check the use of s at the given point */
+static int
+ckuse(Sym *s, Sym *s0, Use *u)
+{
+	Sym *s1;
+
+	s1 = u->p->from.sym;
+// print("ckuse %s %s %s\n", s->name, s0->name, s1 ? s1->name : "nil");
+	if(u->ct == nil){	/* in data area */
+		if(s0 == s && !cksymuse(s1, s0->thumb)){
+			// print("%s: cksymuse fails\n", s0->name);
+			return 0;
+		}
+		for(u = s1->use; u != U; u = u->link)
+			if(!ckuse(s1, s0, u))
+				return 0;
+	}
+	else{		/* in text area */
+		if(u->ct->from.sym->thumb != s0->thumb){
+			// print("%s(%d): foreign call %s(%d)\n", s0->name, s0->thumb, u->ct->from.sym->name, u->ct->from.sym->thumb);
+			return 0;
+		}
+		return ckfpuse(u->p, u->ct, s0, s);
+	}
+	return 1;
+}
+		
+static void
+setuse(Sym *s, Sym *s0, Use *u)
+{
+	Sym *s1;
+
+	s1 = u->p->from.sym;
+	if(u->ct == nil){	/* in data area */
+		for(u = s1->use; u != U; u = u->link)
+			setuse(s1, s0, u);
+	}
+	else{		/* in text area */
+		setfpuse(u->p, s0, s);
+	}
+}
+		
+/* detect BX O(R) which can be done as BL O(R) */
+void
+fnptrs()
+{
+	int i;
+	Sym *s;
+	Prog *p;
+	Use *u;
+	
+	for(i=0; i<NHASH; i++){
+		for(s = hash[i]; s != S; s = s->link){
+			if(s->fnptr && (s->type == STEXT || s->type == SLEAF || s->type == SCONST)){
+				// print("%s : fnptr %d %d\n", s->name, s->thumb, s->foreign);
+			}
+		}
+	}	
+	/* record use of syms */
+	for(p = firstp; p != P; p = p->link){
+		if(p->as == ATEXT)
+			curtext = p;
+		else{
+			fused(&p->from, p, curtext);
+			fused(&p->to, p, curtext);
+		}
+	}
+	for(p = datap; p != P; p = p->link)
+		fused(&p->to, p, nil);
+
+	/* now look for fn ptrs */
+	for(i=0; i<NHASH; i++){
+		for(s = hash[i]; s != S; s = s->link){
+			if(s->fnptr && (s->type == STEXT || s->type == SLEAF || s->type == SCONST)){
+				for(u = s->use; u != U; u = u->link){
+					if(!ckuse(s, s, u))
+						break;
+				}
+				if(u == U){		// can simplify
+					for(u = s->use; u != U; u = u->link)
+						setuse(s, s, u);
+				}
+			}	
+		}
+	}
+
+	/*  now free Use structures */
+}
+
+void
+import(void)
+{
+	int i;
+	Sym *s;
+
+	for(i = 0; i < NHASH; i++)
+		for(s = hash[i]; s != S; s = s->link)
+			if(s->sig != 0 && s->type == SXREF && (nimports == 0 || s->subtype == SIMPORT)){
+				undefsym(s);
+				Bprint(&bso, "IMPORT: %s sig=%lux v=%ld\n", s->name, s->sig, s->value);
+			}
+}
+
+void
+ckoff(Sym *s, long v)
+{
+	if(v < 0 || v >= 1<<Roffset)
+		diag("relocation offset %ld for %s out of range", v, s->name);
+}
+
+static Prog*
+newdata(Sym *s, int o, int w, int t)
+{
+	Prog *p;
+
+	p = prg();
+	p->link = datap;
+	datap = p;
+	p->as = ADATA;
+	p->reg = w;
+	p->from.type = D_OREG;
+	p->from.name = t;
+	p->from.sym = s;
+	p->from.offset = o;
+	p->to.type = D_CONST;
+	p->to.name = D_NONE;
+	return p;
+}
+
+void
+export(void)
+{
+	int i, j, n, off, nb, sv, ne;
+	Sym *s, *et, *str, **esyms;
+	Prog *p;
+	char buf[NSNAME], *t;
+
+	n = 0;
+	for(i = 0; i < NHASH; i++)
+		for(s = hash[i]; s != S; s = s->link)
+			if(s->sig != 0 && s->type != SXREF && s->type != SUNDEF && (nexports == 0 || s->subtype == SEXPORT))
+				n++;
+	esyms = malloc(n*sizeof(Sym*));
+	ne = n;
+	n = 0;
+	for(i = 0; i < NHASH; i++)
+		for(s = hash[i]; s != S; s = s->link)
+			if(s->sig != 0 && s->type != SXREF && s->type != SUNDEF && (nexports == 0 || s->subtype == SEXPORT))
+				esyms[n++] = s;
+	for(i = 0; i < ne-1; i++)
+		for(j = i+1; j < ne; j++)
+			if(strcmp(esyms[i]->name, esyms[j]->name) > 0){
+				s = esyms[i];
+				esyms[i] = esyms[j];
+				esyms[j] = s;
+			}
+
+	nb = 0;
+	off = 0;
+	et = lookup(EXPTAB, 0);
+	if(et->type != 0 && et->type != SXREF)
+		diag("%s already defined", EXPTAB);
+	et->type = SDATA;
+	str = lookup(".string", 0);
+	if(str->type == 0)
+		str->type = SDATA;
+	sv = str->value;
+	for(i = 0; i < ne; i++){
+		s = esyms[i];
+		Bprint(&bso, "EXPORT: %s sig=%lux t=%d\n", s->name, s->sig, s->type);
+
+		/* signature */
+		p = newdata(et, off, sizeof(long), D_EXTERN);
+		off += sizeof(long);
+		p->to.offset = s->sig;
+
+		/* address */
+		p = newdata(et, off, sizeof(long), D_EXTERN);
+		off += sizeof(long);
+		p->to.name = D_EXTERN;
+		p->to.sym = s;
+
+		/* string */
+		t = s->name;
+		n = strlen(t)+1;
+		for(;;){
+			buf[nb++] = *t;
+			sv++;
+			if(nb >= NSNAME){
+				p = newdata(str, sv-NSNAME, NSNAME, D_STATIC);
+				p->to.type = D_SCONST;
+				p->to.sval = malloc(NSNAME);
+				memmove(p->to.sval, buf, NSNAME);
+				nb = 0;
+			}
+			if(*t++ == 0)
+				break;
+		}
+
+		/* name */
+		p = newdata(et, off, sizeof(long), D_EXTERN);
+		off += sizeof(long);
+		p->to.name = D_STATIC;
+		p->to.sym = str;
+		p->to.offset = sv-n;
+	}
+
+	if(nb > 0){
+		p = newdata(str, sv-nb, nb, D_STATIC);
+		p->to.type = D_SCONST;
+		p->to.sval = malloc(NSNAME);
+		memmove(p->to.sval, buf, nb);
+	}
+
+	for(i = 0; i < 3; i++){
+		newdata(et, off, sizeof(long), D_EXTERN);
+		off += sizeof(long);
+	}
+	et->value = off;
+	if(sv == 0)
+		sv = 1;
+	str->value = sv;
+	exports = ne;
+	free(esyms);
+}