1 files changed, 349 insertions, 194 deletions

diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 1cb25512e..ff9b36208 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -5,8 +5,11 @@
 #include	<u.h>
 #include	<libc.h>
 #include	"go.h"
+#include	"../ld/textflag.h"
 
-static	Node*	walkprint(Node*, NodeList**, int);
+static	Node*	walkprint(Node*, NodeList**);
+static	Node*	writebarrierfn(char*, Type*, Type*);
+static	Node*	applywritebarrier(Node*, NodeList**);
 static	Node*	mapfn(char*, Type*);
 static	Node*	mapfndel(char*, Type*);
 static	Node*	ascompatee1(int, Node*, Node*, NodeList**);
@@ -29,6 +32,7 @@ static	void	walkmul(Node**, NodeList**);
 static	void	walkdiv(Node**, NodeList**);
 static	int	bounded(Node*, int64);
 static	Mpint	mpzero;
+static	void	walkprintfunc(Node**, NodeList**);
 
 void
 walk(Node *fn)
@@ -134,6 +138,8 @@ walkstmt(Node **np)
 	n = *np;
 	if(n == N)
 		return;
+	if(n->dodata == 2) // don't walk, generated by anylit.
+		return;
 
 	setlineno(n);
 
@@ -221,8 +227,7 @@ walkstmt(Node **np)
 		switch(n->left->op) {
 		case OPRINT:
 		case OPRINTN:
-			walkexprlist(n->left->list, &n->ninit);
-			n->left = walkprint(n->left, &n->ninit, 1);
+			walkprintfunc(&n->left, &n->ninit);
 			break;
 		case OCOPY:
 			n->left = copyany(n->left, &n->ninit, 1);
@@ -255,8 +260,7 @@ walkstmt(Node **np)
 		switch(n->left->op) {
 		case OPRINT:
 		case OPRINTN:
-			walkexprlist(n->left->list, &n->ninit);
-			n->left = walkprint(n->left, &n->ninit, 1);
+			walkprintfunc(&n->left, &n->ninit);
 			break;
 		case OCOPY:
 			n->left = copyany(n->left, &n->ninit, 1);
@@ -538,15 +542,15 @@ walkexpr(Node **np, NodeList **init)
 	case OPRINT:
 	case OPRINTN:
 		walkexprlist(n->list, init);
-		n = walkprint(n, init, 0);
+		n = walkprint(n, init);
 		goto ret;
 
 	case OPANIC:
-		n = mkcall("panic", T, init, n->left);
+		n = mkcall("gopanic", T, init, n->left);
 		goto ret;
 
 	case ORECOVER:
-		n = mkcall("recover", n->type, init, nod(OADDR, nodfp, N));
+		n = mkcall("gorecover", n->type, init, nod(OADDR, nodfp, N));
 		goto ret;
 
 	case OLITERAL:
@@ -609,7 +613,7 @@ walkexpr(Node **np, NodeList **init)
 		if(oaslit(n, init))
 			goto ret;
 
-		if(n->right == N)
+		if(n->right == N || iszero(n->right) && !flag_race)
 			goto ret;
 
 		switch(n->right->op) {
@@ -632,6 +636,7 @@ walkexpr(Node **np, NodeList **init)
 			r = convas(nod(OAS, n->left, n->right), init);
 			r->dodata = n->dodata;
 			n = r;
+			n = applywritebarrier(n, init);
 		}
 
 		goto ret;
@@ -643,6 +648,8 @@ walkexpr(Node **np, NodeList **init)
 		walkexprlistsafe(n->rlist, init);
 		ll = ascompatee(OAS, n->list, n->rlist, init);
 		ll = reorder3(ll);
+		for(lr = ll; lr != nil; lr = lr->next)
+			lr->n = applywritebarrier(lr->n, init);
 		n = liststmt(ll);
 		goto ret;
 
@@ -655,6 +662,8 @@ walkexpr(Node **np, NodeList **init)
 		walkexpr(&r, init);
 
 		ll = ascompatet(n->op, n->list, &r->type, 0, init);
+		for(lr = ll; lr != nil; lr = lr->next)
+			lr->n = applywritebarrier(lr->n, init);
 		n = liststmt(concat(list1(r), ll));
 		goto ret;
 
@@ -672,7 +681,7 @@ walkexpr(Node **np, NodeList **init)
 			n1 = nod(OADDR, n->list->n, N);
 		n1->etype = 1; // addr does not escape
 		fn = chanfn("chanrecv2", 2, r->left->type);
-		r = mkcall1(fn, types[TBOOL], init, typename(r->left->type), r->left, n1);
+		r = mkcall1(fn, n->list->next->n->type, init, typename(r->left->type), r->left, n1);
 		n = nod(OAS, n->list->next->n, r);
 		typecheck(&n, Etop);
 		goto ret;
@@ -687,7 +696,7 @@ walkexpr(Node **np, NodeList **init)
 		walkexpr(&r->right, init);
 		t = r->left->type;
 		p = nil;
-		if(t->type->width <= 128) { // Check ../../pkg/runtime/hashmap.c:MAXVALUESIZE before changing.
+		if(t->type->width <= 128) { // Check ../../runtime/hashmap.c:MAXVALUESIZE before changing.
 			switch(simsimtype(t->down)) {
 			case TINT32:
 			case TUINT32:
@@ -722,6 +731,12 @@ walkexpr(Node **np, NodeList **init)
 		var->typecheck = 1;
 		fn = mapfn(p, t);
 		r = mkcall1(fn, getoutargx(fn->type), init, typename(t), r->left, key);
+
+		// mapaccess2* returns a typed bool, but due to spec changes,
+		// the boolean result of i.(T) is now untyped so we make it the
+		// same type as the variable on the lhs.
+		if(!isblank(n->list->next->n))
+			r->type->type->down->type = n->list->next->n->type;
 		n->rlist = list1(r);
 		n->op = OAS2FUNC;
 		n->list->n = var;
@@ -769,6 +784,12 @@ walkexpr(Node **np, NodeList **init)
 			*p = '\0';
 			
 			fn = syslook(buf, 1);
+
+			// runtime.assert(E|I)2TOK returns a typed bool, but due
+			// to spec changes, the boolean result of i.(T) is now untyped
+			// so we make it the same type as the variable on the lhs.
+			if(!isblank(n->list->next->n))
+				fn->type->type->down->type->type = n->list->next->n->type;
 			ll = list1(typename(r->type));
 			ll = list(ll, r->left);
 			argtype(fn, r->left->type);
@@ -821,9 +842,7 @@ walkexpr(Node **np, NodeList **init)
 		walkexpr(&n->left, init);
 
 		// Optimize convT2E as a two-word copy when T is uintptr-shaped.
-		if(!isinter(n->left->type) && isnilinter(n->type) &&
-		   (n->left->type->width == widthptr) &&
-		   isint[simsimtype(n->left->type)]) {
+		if(isnilinter(n->type) && isdirectiface(n->left->type) && n->left->type->width == widthptr && isint[simsimtype(n->left->type)]) {
 			l = nod(OEFACE, typename(n->left->type), n->left);
 			l->type = n->type;
 			l->typecheck = n->typecheck;
@@ -865,14 +884,13 @@ walkexpr(Node **np, NodeList **init)
 				l->class = PEXTERN;
 				l->xoffset = 0;
 				sym->def = l;
-				ggloblsym(sym, widthptr, 1, 0);
+				ggloblsym(sym, widthptr, DUPOK|NOPTR);
 			}
 			l = nod(OADDR, sym->def, N);
 			l->addable = 1;
 			ll = list(ll, l);
 
-			if(n->left->type->width == widthptr &&
-		   	   isint[simsimtype(n->left->type)]) {
+			if(isdirectiface(n->left->type) && n->left->type->width == widthptr && isint[simsimtype(n->left->type)]) {
 				/* For pointer types, we can make a special form of optimization
 				 *
 				 * These statements are put onto the expression init list:
@@ -1073,7 +1091,7 @@ walkexpr(Node **np, NodeList **init)
 
 		t = n->left->type;
 		p = nil;
-		if(t->type->width <= 128) {  // Check ../../pkg/runtime/hashmap.c:MAXVALUESIZE before changing.
+		if(t->type->width <= 128) {  // Check ../../runtime/hashmap.c:MAXVALUESIZE before changing.
 			switch(simsimtype(t->down)) {
 			case TINT32:
 			case TUINT32:
@@ -1371,7 +1389,6 @@ walkexpr(Node **np, NodeList **init)
 	case OMAPLIT:
 	case OSTRUCTLIT:
 	case OPTRLIT:
-		// XXX TODO do we need to clear var?
 		var = temp(n->type);
 		anylit(0, n, var, init);
 		n = var;
@@ -1471,8 +1488,13 @@ ascompatee(int op, NodeList *nl, NodeList *nr, NodeList **init)
 static int
 fncall(Node *l, Type *rt)
 {
+	Node r;
+
 	if(l->ullman >= UINF || l->op == OINDEXMAP)
 		return 1;
+	memset(&r, 0, sizeof r);
+	if(needwritebarrier(l, &r))
+		return 1;
 	if(eqtype(l->type, rt))
 		return 0;
 	return 1;
@@ -1523,8 +1545,10 @@ ascompatet(int op, NodeList *nl, Type **nr, int fp, NodeList **init)
 		a = nod(OAS, l, nodarg(r, fp));
 		a = convas(a, init);
 		ullmancalc(a);
-		if(a->ullman >= UINF)
+		if(a->ullman >= UINF) {
+			dump("ascompatet ucount", a);
 			ucount++;
+		}
 		nn = list(nn, a);
 		r = structnext(&saver);
 	}
@@ -1732,7 +1756,7 @@ ret:
 
 // generate code for print
 static Node*
-walkprint(Node *nn, NodeList **init, int defer)
+walkprint(Node *nn, NodeList **init)
 {
 	Node *r;
 	Node *n;
@@ -1740,31 +1764,17 @@ walkprint(Node *nn, NodeList **init, int defer)
 	Node *on;
 	Type *t;
 	int notfirst, et, op;
-	NodeList *calls, *intypes, *args;
-	Fmt fmt;
+	NodeList *calls;
 
 	on = nil;
 	op = nn->op;
 	all = nn->list;
 	calls = nil;
 	notfirst = 0;
-	intypes = nil;
-	args = nil;
-
-	memset(&fmt, 0, sizeof fmt);
-	if(defer) {
-		// defer print turns into defer printf with format string
-		fmtstrinit(&fmt);
-		intypes = list(intypes, nod(ODCLFIELD, N, typenod(types[TSTRING])));
-		args = list1(nod(OXXX, N, N));
-	}
 
 	for(l=all; l; l=l->next) {
 		if(notfirst) {
-			if(defer)
-				fmtprint(&fmt, " ");
-			else
-				calls = list(calls, mkcall("printsp", T, init));
+			calls = list(calls, mkcall("printsp", T, init));
 		}
 		notfirst = op == OPRINTN;
 
@@ -1792,119 +1802,63 @@ walkprint(Node *nn, NodeList **init, int defer)
 		t = n->type;
 		et = n->type->etype;
 		if(isinter(n->type)) {
-			if(defer) {
-				if(isnilinter(n->type))
-					fmtprint(&fmt, "%%e");
-				else
-					fmtprint(&fmt, "%%i");
-			} else {
-				if(isnilinter(n->type))
-					on = syslook("printeface", 1);
-				else
-					on = syslook("printiface", 1);
-				argtype(on, n->type);		// any-1
-			}
+			if(isnilinter(n->type))
+				on = syslook("printeface", 1);
+			else
+				on = syslook("printiface", 1);
+			argtype(on, n->type);		// any-1
 		} else if(isptr[et] || et == TCHAN || et == TMAP || et == TFUNC || et == TUNSAFEPTR) {
-			if(defer) {
-				fmtprint(&fmt, "%%p");
-			} else {
-				on = syslook("printpointer", 1);
-				argtype(on, n->type);	// any-1
-			}
+			on = syslook("printpointer", 1);
+			argtype(on, n->type);	// any-1
 		} else if(isslice(n->type)) {
-			if(defer) {
-				fmtprint(&fmt, "%%a");
-			} else {
-				on = syslook("printslice", 1);
-				argtype(on, n->type);	// any-1
-			}
+			on = syslook("printslice", 1);
+			argtype(on, n->type);	// any-1
 		} else if(isint[et]) {
-			if(defer) {
-				if(et == TUINT64)
-					fmtprint(&fmt, "%%U");
-				else {
-					fmtprint(&fmt, "%%D");
-					t = types[TINT64];
-				}
-			} else {
-				if(et == TUINT64)
-					on = syslook("printuint", 0);
+			if(et == TUINT64) {
+				if((t->sym->pkg == runtimepkg || compiling_runtime) && strcmp(t->sym->name, "hex") == 0)
+					on = syslook("printhex", 0);
 				else
-					on = syslook("printint", 0);
-			}
-		} else if(isfloat[et]) {
-			if(defer) {
-				fmtprint(&fmt, "%%f");
-				t = types[TFLOAT64];
+					on = syslook("printuint", 0);
 			} else
-				on = syslook("printfloat", 0);
+				on = syslook("printint", 0);
+		} else if(isfloat[et]) {
+			on = syslook("printfloat", 0);
 		} else if(iscomplex[et]) {
-			if(defer) {
-				fmtprint(&fmt, "%%C");
-				t = types[TCOMPLEX128];
-			} else
-				on = syslook("printcomplex", 0);
+			on = syslook("printcomplex", 0);
 		} else if(et == TBOOL) {
-			if(defer)
-				fmtprint(&fmt, "%%t");
-			else
-				on = syslook("printbool", 0);
+			on = syslook("printbool", 0);
 		} else if(et == TSTRING) {
-			if(defer)
-				fmtprint(&fmt, "%%S");
-			else
-				on = syslook("printstring", 0);
+			on = syslook("printstring", 0);
 		} else {
 			badtype(OPRINT, n->type, T);
 			continue;
 		}
 
-		if(!defer) {
-			t = *getinarg(on->type);
-			if(t != nil)
-				t = t->type;
-			if(t != nil)
-				t = t->type;
-		}
+		t = *getinarg(on->type);
+		if(t != nil)
+			t = t->type;
+		if(t != nil)
+			t = t->type;
 
 		if(!eqtype(t, n->type)) {
 			n = nod(OCONV, n, N);
 			n->type = t;
 		}
 
-		if(defer) {
-			intypes = list(intypes, nod(ODCLFIELD, N, typenod(t)));
-			args = list(args, n);
-		} else {
-			r = nod(OCALL, on, N);
-			r->list = list1(n);
-			calls = list(calls, r);
-		}
+		r = nod(OCALL, on, N);
+		r->list = list1(n);
+		calls = list(calls, r);
 	}
 
-	if(defer) {
-		if(op == OPRINTN)
-			fmtprint(&fmt, "\n");
-		on = syslook("goprintf", 1);
-		on->type = functype(nil, intypes, nil);
-		args->n = nod(OLITERAL, N, N);
-		args->n->val.ctype = CTSTR;
-		args->n->val.u.sval = strlit(fmtstrflush(&fmt));
-		r = nod(OCALL, on, N);
-		r->list = args;
-		typecheck(&r, Etop);
-		walkexpr(&r, init);
-	} else {
-		if(op == OPRINTN)
-			calls = list(calls, mkcall("printnl", T, nil));
-		typechecklist(calls, Etop);
-		walkexprlist(calls, init);
+	if(op == OPRINTN)
+		calls = list(calls, mkcall("printnl", T, nil));
+	typechecklist(calls, Etop);
+	walkexprlist(calls, init);
 
-		r = nod(OEMPTY, N, N);
-		typecheck(&r, Etop);
-		walkexpr(&r, init);
-		r->ninit = calls;
-	}
+	r = nod(OEMPTY, N, N);
+	typecheck(&r, Etop);
+	walkexpr(&r, init);
+	r->ninit = calls;
 	return r;
 }
 
@@ -1914,11 +1868,166 @@ callnew(Type *t)
 	Node *fn;
 
 	dowidth(t);
-	fn = syslook("new", 1);
+	fn = syslook("newobject", 1);
 	argtype(fn, t);
 	return mkcall1(fn, ptrto(t), nil, typename(t));
 }
 
+static int
+isstack(Node *n)
+{
+	while(n->op == ODOT || n->op == OPAREN || n->op == OCONVNOP || n->op == OINDEX && isfixedarray(n->left->type))
+		n = n->left;
+	
+	switch(n->op) {
+	case OINDREG:
+		// OINDREG only ends up in walk if it's indirect of SP.
+		return 1;
+
+	case ONAME:
+		switch(n->class) {
+		case PAUTO:
+		case PPARAM:
+		case PPARAMOUT:
+			return 1;
+		}
+		break;
+	}
+	
+	return 0;
+}
+
+static int
+isglobal(Node *n)
+{
+	while(n->op == ODOT || n->op == OPAREN || n->op == OCONVNOP || n->op == OINDEX && isfixedarray(n->left->type))
+		n = n->left;
+	
+	switch(n->op) {
+	case ONAME:
+		switch(n->class) {
+		case PEXTERN:
+			return 1;
+		}
+		break;
+	}
+	
+	return 0;
+}
+
+// Do we need a write barrier for the assignment l = r?
+int
+needwritebarrier(Node *l, Node *r)
+{
+	if(!use_writebarrier)
+		return 0;
+
+	if(l == N || isblank(l))
+		return 0;
+
+	// No write barrier for write of non-pointers.
+	dowidth(l->type);
+	if(!haspointers(l->type))
+		return 0;
+
+	// No write barrier for write to stack.
+	if(isstack(l))
+		return 0;
+
+	// No write barrier for implicit or explicit zeroing.
+	if(r == N || iszero(r))
+		return 0;
+
+	// No write barrier for initialization to constant.
+	if(r->op == OLITERAL)
+		return 0;
+
+	// No write barrier for storing static (read-only) data.
+	if(r->op == ONAME && strncmp(r->sym->name, "statictmp_", 10) == 0)
+		return 0;
+
+	// No write barrier for storing address of stack values,
+	// which are guaranteed only to be written to the stack.
+	if(r->op == OADDR && isstack(r->left))
+		return 0;
+
+	// No write barrier for storing address of global, which
+	// is live no matter what.
+	if(r->op == OADDR && isglobal(r->left))
+		return 0;
+
+	// No write barrier for reslice: x = x[0:y] or x = append(x, ...).
+	// Both are compiled to modify x directly.
+	// In the case of append, a write barrier may still be needed
+	// if the underlying array grows, but the append code can
+	// generate the write barrier directly in that case.
+	// (It does not yet, but the cost of the write barrier will be
+	// small compared to the cost of the allocation.)
+	if(r->reslice) {
+		switch(r->op) {
+		case OSLICE:
+		case OSLICE3:
+		case OSLICESTR:
+		case OAPPEND:
+			break;
+		default:
+			dump("bad reslice-l", l);
+			dump("bad reslice-r", r);
+			break;
+		}
+		return 0;
+	}
+
+	// Otherwise, be conservative and use write barrier.
+	return 1;
+}
+
+// TODO(rsc): Perhaps componentgen should run before this.
+static Node*
+applywritebarrier(Node *n, NodeList **init)
+{
+	Node *l, *r;
+	Type *t;
+
+	if(n->left && n->right && needwritebarrier(n->left, n->right)) {
+		t = n->left->type;
+		l = nod(OADDR, n->left, N);
+		l->etype = 1; // addr does not escape
+		if(t->width == widthptr) {
+			n = mkcall1(writebarrierfn("writebarrierptr", t, n->right->type), T, init,
+				l, n->right);
+		} else if(t->etype == TSTRING) {
+			n = mkcall1(writebarrierfn("writebarrierstring", t, n->right->type), T, init,
+				l, n->right);
+		} else if(isslice(t)) {
+			n = mkcall1(writebarrierfn("writebarrierslice", t, n->right->type), T, init,
+				l, n->right);
+		} else if(isinter(t)) {
+			n = mkcall1(writebarrierfn("writebarrieriface", t, n->right->type), T, init,
+				l, n->right);
+		} else if(t->width == 2*widthptr) {
+			n = mkcall1(writebarrierfn("writebarrierfat2", t, n->right->type), T, init,
+				l, nodnil(), n->right);
+		} else if(t->width == 3*widthptr) {
+			n = mkcall1(writebarrierfn("writebarrierfat3", t, n->right->type), T, init,
+				l, nodnil(), n->right);
+		} else if(t->width == 4*widthptr) {
+			n = mkcall1(writebarrierfn("writebarrierfat4", t, n->right->type), T, init,
+				l, nodnil(), n->right);
+		} else {
+			r = n->right;
+			while(r->op == OCONVNOP)
+				r = r->left;
+			r = nod(OADDR, r, N);
+			r->etype = 1; // addr does not escape
+			//warnl(n->lineno, "writebarrierfat %T %N", t, r);
+			n = mkcall1(writebarrierfn("writebarrierfat", t, r->left->type), T, init,
+				typename(t), l, r);
+		}
+	}
+	return n;
+}
+
 static Node*
 convas(Node *n, NodeList **init)
 {
@@ -1958,11 +2067,10 @@ convas(Node *n, NodeList **init)
 		goto out;
 	}
 
-	if(eqtype(lt, rt))
-		goto out;
-
-	n->right = assignconv(n->right, lt, "assignment");
-	walkexpr(&n->right, init);
+	if(!eqtype(lt, rt)) {
+		n->right = assignconv(n->right, lt, "assignment");
+		walkexpr(&n->right, init);
+	}
 
 out:
 	ullmancalc(n);
@@ -2355,6 +2463,8 @@ paramstoheap(Type **argin, int out)
 			continue;
 
 		// generate allocation & copying code
+		if(compiling_runtime)
+			yyerror("%N escapes to heap, not allowed in runtime.", v);
 		if(v->alloc == nil)
 			v->alloc = callnew(v->type);
 		nn = list(nn, nod(OAS, v->heapaddr, v->alloc));
@@ -2512,6 +2622,17 @@ mapfndel(char *name, Type *t)
 }
 
 static Node*
+writebarrierfn(char *name, Type *l, Type *r)
+{
+	Node *fn;
+
+	fn = syslook(name, 1);
+	argtype(fn, l);
+	argtype(fn, r);
+	return fn;
+}
+
+static Node*
 addstr(Node *n, NodeList **init)
 {
 	Node *r, *cat, *slice;
@@ -2620,7 +2741,7 @@ appendslice(Node *n, NodeList **init)
 		if(l2->type->etype == TSTRING)
 			fn = syslook("slicestringcopy", 1);
 		else
-			fn = syslook("copy", 1);
+			fn = syslook("slicecopy", 1);
 		argtype(fn, l1->type);
 		argtype(fn, l2->type);
 		nt = mkcall1(fn, types[TINT], &l,
@@ -2758,7 +2879,7 @@ copyany(Node *n, NodeList **init, int runtimecall)
 		if(n->right->type->etype == TSTRING)
 			fn = syslook("slicestringcopy", 1);
 		else
-			fn = syslook("copy", 1);
+			fn = syslook("slicecopy", 1);
 		argtype(fn, n->left->type);
 		argtype(fn, n->right->type);
 		return mkcall1(fn, n->type, init,
@@ -2863,14 +2984,14 @@ sliceany(Node* n, NodeList **init)
 			lb = N;
 	}
 
-	// dynamic checks convert all bounds to unsigned to save us the bound < 0 comparison
-	// generate
-	//     if hb > bound || lb > hb { panicslice() }
+	// Checking src[lb:hb:cb] or src[lb:hb].
+	// if chk0 || chk1 || chk2 { panicslice() }
 	chk = N;
-	chk0 = N;
-	chk1 = N;
-	chk2 = N;
+	chk0 = N; // cap(src) < cb
+	chk1 = N; // cb < hb for src[lb:hb:cb]; cap(src) < hb for src[lb:hb]
+	chk2 = N; // hb < lb
 
+	// All comparisons are unsigned to avoid testing < 0.
 	bt = types[simtype[TUINT]];
 	if(cb != N && cb->type->width > 4)
 		bt = types[TUINT64];
@@ -3010,10 +3131,10 @@ eqfor(Type *t)
 	n = newname(sym);
 	n->class = PFUNC;
 	ntype = nod(OTFUNC, N, N);
-	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(ptrto(types[TBOOL]))));
-	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(types[TUINTPTR])));
 	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(ptrto(t))));
 	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(ptrto(t))));
+	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(types[TUINTPTR])));
+	ntype->rlist = list(ntype->rlist, nod(ODCLFIELD, N, typenod(types[TBOOL])));
 	typecheck(&ntype, Etype);
 	n->type = ntype->type;
 	return n;
@@ -3034,10 +3155,9 @@ countfield(Type *t)
 static void
 walkcompare(Node **np, NodeList **init)
 {
-	Node *n, *l, *r, *fn, *call, *a, *li, *ri, *expr;
+	Node *n, *l, *r, *call, *a, *li, *ri, *expr, *cmpl, *cmpr;
 	int andor, i;
 	Type *t, *t1;
-	static Node *tempbool;
 	
 	n = *np;
 	
@@ -3055,17 +3175,25 @@ walkcompare(Node **np, NodeList **init)
 		break;
 	}
 	
-	if(!islvalue(n->left) || !islvalue(n->right))
-		goto hard;
+	cmpl = n->left;
+	while(cmpl != N && cmpl->op == OCONVNOP)
+		cmpl = cmpl->left;
+	cmpr = n->right;
+	while(cmpr != N && cmpr->op == OCONVNOP)
+		cmpr = cmpr->left;
+	
+	if(!islvalue(cmpl) || !islvalue(cmpr)) {
+		fatal("arguments of comparison must be lvalues - %N %N", cmpl, cmpr);
+	}
 
 	l = temp(ptrto(t));
-	a = nod(OAS, l, nod(OADDR, n->left, N));
+	a = nod(OAS, l, nod(OADDR, cmpl, N));
 	a->right->etype = 1;  // addr does not escape
 	typecheck(&a, Etop);
 	*init = list(*init, a);
 
 	r = temp(ptrto(t));
-	a = nod(OAS, r, nod(OADDR, n->right, N));
+	a = nod(OAS, r, nod(OADDR, cmpr, N));
 	a->right->etype = 1;  // addr does not escape
 	typecheck(&a, Etop);
 	*init = list(*init, a);
@@ -3115,57 +3243,16 @@ walkcompare(Node **np, NodeList **init)
 		goto ret;
 	}
 
-	// Chose not to inline, but still have addresses.
-	// Call equality function directly.
-	// The equality function requires a bool pointer for
-	// storing its address, because it has to be callable
-	// from C, and C can't access an ordinary Go return value.
-	// To avoid creating many temporaries, cache one per function.
-	if(tempbool == N || tempbool->curfn != curfn)
-		tempbool = temp(types[TBOOL]);
-	
+	// Chose not to inline.  Call equality function directly.
 	call = nod(OCALL, eqfor(t), N);
-	a = nod(OADDR, tempbool, N);
-	a->etype = 1;  // does not escape
-	call->list = list(call->list, a);
-	call->list = list(call->list, nodintconst(t->width));
 	call->list = list(call->list, l);
 	call->list = list(call->list, r);
-	typecheck(&call, Etop);
-	walkstmt(&call);
-	*init = list(*init, call);
-
-	// tempbool cannot be used directly as multiple comparison
-	// expressions may exist in the same statement. Create another
-	// temporary to hold the value (its address is not taken so it can
-	// be optimized away).
-	r = temp(types[TBOOL]);
-	a = nod(OAS, r, tempbool);
-	typecheck(&a, Etop);
-	walkstmt(&a);
-	*init = list(*init, a);
-
+	call->list = list(call->list, nodintconst(t->width));
+	r = call;
 	if(n->op != OEQ)
 		r = nod(ONOT, r, N);
 	goto ret;
 
-hard:
-	// Cannot take address of one or both of the operands.
-	// Instead, pass directly to runtime helper function.
-	// Easier on the stack than passing the address
-	// of temporary variables, because we are better at reusing
-	// the argument space than temporary variable space.
-	fn = syslook("equal", 1);
-	l = n->left;
-	r = n->right;
-	argtype(fn, n->left->type);
-	argtype(fn, n->left->type);
-	r = mkcall1(fn, n->type, init, typename(n->left->type), l, r);
-	if(n->op == ONE) {
-		r = nod(ONOT, r, N);
-	}
-	goto ret;
-
 ret:
 	typecheck(&r, Erv);
 	walkexpr(&r, init);
@@ -3780,3 +3867,71 @@ candiscard(Node *n)
 	
 	return 1;
 }
+
+// rewrite
+//	print(x, y, z)
+// into
+//	func(a1, a2, a3) {
+//		print(a1, a2, a3)
+//	}(x, y, z)
+// and same for println.
+static void
+walkprintfunc(Node **np, NodeList **init)
+{
+	Node *n;
+	Node *a, *fn, *t, *oldfn;
+	NodeList *l, *printargs;
+	int num;
+	char buf[100];
+	static int prgen;
+	
+	n = *np;
+
+	if(n->ninit != nil) {
+		walkstmtlist(n->ninit);
+		*init = concat(*init, n->ninit);
+		n->ninit = nil;
+	}
+
+	t = nod(OTFUNC, N, N);
+	num = 0;
+	printargs = nil;
+	for(l=n->list; l != nil; l=l->next) {
+		snprint(buf, sizeof buf, "a%d", num++);
+		a = nod(ODCLFIELD, newname(lookup(buf)), typenod(l->n->type));
+		t->list = list(t->list, a);
+		printargs = list(printargs, a->left);
+	}
+
+	fn = nod(ODCLFUNC, N, N);
+	snprint(buf, sizeof buf, "print·%d", ++prgen);
+	fn->nname = newname(lookup(buf));
+	fn->nname->defn = fn;
+	fn->nname->ntype = t;
+	declare(fn->nname, PFUNC);
+
+	oldfn = curfn;
+	curfn = nil;
+	funchdr(fn);
+	
+	a = nod(n->op, N, N);
+	a->list = printargs;
+	typecheck(&a, Etop);
+	walkstmt(&a);
+	
+	fn->nbody = list1(a);
+
+	funcbody(fn);
+	
+	typecheck(&fn, Etop);
+	typechecklist(fn->nbody, Etop);
+	xtop = list(xtop, fn);
+	curfn = oldfn;
+
+	a = nod(OCALL, N, N);
+	a->left = fn->nname;
+	a->list = n->list;
+	typecheck(&a, Etop);
+	walkexpr(&a, init);
+	*np = a;
+}