diff --git a/src/cmd/gc/builtin.c.boot b/src/cmd/gc/builtin.c.boot
index 3fb75f8649..1d881c9d8e 100644
--- a/src/cmd/gc/builtin.c.boot
+++ b/src/cmd/gc/builtin.c.boot
@@ -1,6 +1,6 @@
 char *runtimeimport =
 	"package runtime\n"
-	"func \"\".mal (? int32) (? *any)\n"
+	"func \"\".mal (? int32) *any\n"
 	"func \"\".throwindex ()\n"
 	"func \"\".throwreturn ()\n"
 	"func \"\".throwinit ()\n"
@@ -16,17 +16,18 @@ char *runtimeimport =
 	"func \"\".printslice (? any)\n"
 	"func \"\".printnl ()\n"
 	"func \"\".printsp ()\n"
-	"func \"\".catstring (? string, ? string) (? string)\n"
-	"func \"\".cmpstring (? string, ? string) (? int)\n"
-	"func \"\".slicestring (? string, ? int, ? int) (? string)\n"
-	"func \"\".slicestring1 (? string, ? int) (? string)\n"
-	"func \"\".indexstring (? string, ? int) (? uint8)\n"
-	"func \"\".intstring (? int64) (? string)\n"
-	"func \"\".slicebytetostring (? []uint8) (? string)\n"
-	"func \"\".sliceinttostring (? []int) (? string)\n"
-	"func \"\".stringiter (? string, ? int) (? int)\n"
+	"func \"\".printf ()\n"
+	"func \"\".catstring (? string, ? string) string\n"
+	"func \"\".cmpstring (? string, ? string) int\n"
+	"func \"\".slicestring (? string, ? int, ? int) string\n"
+	"func \"\".slicestring1 (? string, ? int) string\n"
+	"func \"\".indexstring (? string, ? int) uint8\n"
+	"func \"\".intstring (? int64) string\n"
+	"func \"\".slicebytetostring (? []uint8) string\n"
+	"func \"\".sliceinttostring (? []int) string\n"
+	"func \"\".stringiter (? string, ? int) int\n"
 	"func \"\".stringiter2 (? string, ? int) (retk int, retv int)\n"
-	"func \"\".slicecopy (to any, fr any, wid uint32) (? int)\n"
+	"func \"\".slicecopy (to any, fr any, wid uint32) int\n"
 	"func \"\".ifaceI2E (iface any) (ret any)\n"
 	"func \"\".ifaceE2I (typ *uint8, iface any) (ret any)\n"
 	"func \"\".ifaceT2E (typ *uint8, elem any) (ret any)\n"
@@ -58,7 +59,7 @@ char *runtimeimport =
 	"func \"\".chansend1 (hchan chan<- any, elem any)\n"
 	"func \"\".chansend2 (hchan chan<- any, elem any) (pres bool)\n"
 	"func \"\".closechan (hchan any)\n"
-	"func \"\".closedchan (hchan any) (? bool)\n"
+	"func \"\".closedchan (hchan any) bool\n"
 	"func \"\".newselect (size int) (sel *uint8)\n"
 	"func \"\".selectsend (sel *uint8, hchan chan<- any, elem any) (selected bool)\n"
 	"func \"\".selectrecv (sel *uint8, hchan <-chan any, elem *any) (selected bool)\n"
@@ -69,24 +70,24 @@ char *runtimeimport =
 	"func \"\".sliceslice (old []any, lb int, hb int, width int) (ary []any)\n"
 	"func \"\".slicearray (old *any, nel int, lb int, hb int, width int) (ary []any)\n"
 	"func \"\".closure ()\n"
-	"func \"\".int64div (? int64, ? int64) (? int64)\n"
-	"func \"\".uint64div (? uint64, ? uint64) (? uint64)\n"
-	"func \"\".int64mod (? int64, ? int64) (? int64)\n"
-	"func \"\".uint64mod (? uint64, ? uint64) (? uint64)\n"
-	"func \"\".float64toint64 (? float64) (? int64)\n"
-	"func \"\".int64tofloat64 (? int64) (? float64)\n"
+	"func \"\".int64div (? int64, ? int64) int64\n"
+	"func \"\".uint64div (? uint64, ? uint64) uint64\n"
+	"func \"\".int64mod (? int64, ? int64) int64\n"
+	"func \"\".uint64mod (? uint64, ? uint64) uint64\n"
+	"func \"\".float64toint64 (? float64) int64\n"
+	"func \"\".int64tofloat64 (? int64) float64\n"
 	"\n"
 	"$$\n";
 char *unsafeimport =
 	"package unsafe\n"
 	"type \"\".Pointer *any\n"
-	"func \"\".Offsetof (? any) (? int)\n"
-	"func \"\".Sizeof (? any) (? int)\n"
-	"func \"\".Alignof (? any) (? int)\n"
+	"func \"\".Offsetof (? any) int\n"
+	"func \"\".Sizeof (? any) int\n"
+	"func \"\".Alignof (? any) int\n"
 	"func \"\".Typeof (i interface { }) (typ interface { })\n"
 	"func \"\".Reflect (i interface { }) (typ interface { }, addr \"\".Pointer)\n"
 	"func \"\".Unreflect (typ interface { }, addr \"\".Pointer) (ret interface { })\n"
-	"func \"\".New (typ interface { }) (? \"\".Pointer)\n"
-	"func \"\".NewArray (typ interface { }, n int) (? \"\".Pointer)\n"
+	"func \"\".New (typ interface { }) \"\".Pointer\n"
+	"func \"\".NewArray (typ interface { }, n int) \"\".Pointer\n"
 	"\n"
 	"$$\n";
diff --git a/src/cmd/gc/runtime.go b/src/cmd/gc/runtime.go
index 880b9c9d8d..4b9b97136b 100644
--- a/src/cmd/gc/runtime.go
+++ b/src/cmd/gc/runtime.go
@@ -27,6 +27,7 @@ func printeface(any)
 func printslice(any)
 func printnl()
 func printsp()
+func printf()
 
 func catstring(string, string) string
 func cmpstring(string, string) int
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index acccbec2c9..e142814f7b 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -4,7 +4,7 @@
 
 #include	"go.h"
 
-static	Node*	walkprint(Node*, NodeList**);
+static	Node*	walkprint(Node*, NodeList**, int);
 static	Node*	conv(Node*, Type*);
 static	Node*	mapfn(char*, Type*);
 static	Node*	makenewvar(Type*, NodeList**, Node**);
@@ -355,7 +355,18 @@ walkstmt(Node **np)
 
 	case ODEFER:
 		hasdefer = 1;
-		walkexpr(&n->left, &n->ninit);
+		switch(n->left->op) {
+		case OPRINT:
+		case OPRINTN:
+		case OPANIC:
+		case OPANICN:
+			walkexprlist(n->left->list, &n->ninit);
+			n->left = walkprint(n->left, &n->ninit, 1);
+			break;
+		default:
+			walkexpr(&n->left, &n->ninit);
+			break;
+		}
 		break;
 
 	case OFOR:
@@ -539,7 +550,7 @@ walkexpr(Node **np, NodeList **init)
 	case OPANIC:
 	case OPANICN:
 		walkexprlist(n->list, init);
-		n = walkprint(n, init);
+		n = walkprint(n, init, 0);
 		goto ret;
 
 	case OLITERAL:
@@ -1510,7 +1521,7 @@ ret:
 
 // generate code for print
 static Node*
-walkprint(Node *nn, NodeList **init)
+walkprint(Node *nn, NodeList **init, int defer)
 {
 	Node *r;
 	Node *n;
@@ -1518,16 +1529,32 @@ walkprint(Node *nn, NodeList **init)
 	Node *on;
 	Type *t;
 	int notfirst, et, op;
-	NodeList *calls;
+	NodeList *calls, *intypes, *args;
+	Fmt fmt;
 
+	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)
-			calls = list(calls, mkcall("printsp", T, init));
+		if(notfirst) {
+			if(defer)
+				fmtprint(&fmt, " ");
+			else
+				calls = list(calls, mkcall("printsp", T, init));
+		}
 		notfirst = op == OPRINTN || op == OPANICN;
 
 		n = l->n;
@@ -1548,62 +1575,121 @@ walkprint(Node *nn, NodeList **init)
 		if(n->type == T || n->type->etype == TFORW)
 			continue;
 
+		t = n->type;
 		et = n->type->etype;
 		if(isinter(n->type)) {
-			if(isnilinter(n->type))
-				on = syslook("printeface", 1);
-			else
-				on = syslook("printiface", 1);
-			argtype(on, n->type);		// any-1
+			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
+			}
 		} else if(isptr[et] || et == TCHAN || et == TMAP || et == TFUNC) {
-			on = syslook("printpointer", 1);
-			argtype(on, n->type);	// any-1
+			if(defer) {
+				fmtprint(&fmt, "%%p");
+			} else {
+				on = syslook("printpointer", 1);
+				argtype(on, n->type);	// any-1
+			}
 		} else if(isslice(n->type)) {
-			on = syslook("printslice", 1);
-			argtype(on, n->type);	// any-1
+			if(defer) {
+				fmtprint(&fmt, "%%a");
+			} else {
+				on = syslook("printslice", 1);
+				argtype(on, n->type);	// any-1
+			}
 		} else if(isint[et]) {
-			if(et == TUINT64)
-				on = syslook("printuint", 0);
-			else
-				on = syslook("printint", 0);
+			if(defer) {
+				if(et == TUINT64)
+					fmtprint(&fmt, "%%U");
+				else {
+					fmtprint(&fmt, "%%D");
+					t = types[TINT64];
+				}
+			} else {
+				if(et == TUINT64)
+					on = syslook("printuint", 0);
+				else
+					on = syslook("printint", 0);
+			}
 		} else if(isfloat[et]) {
-			on = syslook("printfloat", 0);
+			if(defer) {
+				fmtprint(&fmt, "%%f");
+				t = types[TFLOAT64];
+			} else
+				on = syslook("printfloat", 0);
 		} else if(et == TBOOL) {
-			on = syslook("printbool", 0);
+			if(defer)
+				fmtprint(&fmt, "%%t");
+			else
+				on = syslook("printbool", 0);
 		} else if(et == TSTRING) {
-			on = syslook("printstring", 0);
+			if(defer)
+				fmtprint(&fmt, "%%S");
+			else
+				on = syslook("printstring", 0);
 		} else {
 			badtype(OPRINT, n->type, T);
 			continue;
 		}
 
-		t = *getinarg(on->type);
-		if(t != nil)
-			t = t->type;
-		if(t != nil)
-			t = t->type;
+		if(!defer) {
+			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;
 		}
-		r = nod(OCALL, on, N);
-		r->list = list1(n);
-		calls = list(calls, r);
+		
+		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);
+		}
 	}
 
-	if(op == OPRINTN)
-		calls = list(calls, mkcall("printnl", T, nil));
-	typechecklist(calls, Etop);
-	walkexprlist(calls, init);
-
-	if(op == OPANIC || op == OPANICN)
-		r = mkcall("panicl", T, nil);
-	else
-		r = nod(OEMPTY, N, N);
-	typecheck(&r, Etop);
-	walkexpr(&r, init);
-	r->ninit = calls;
+	if(defer) {
+		if(op == OPRINTN)
+			fmtprint(&fmt, "\n");
+		if(op == OPANIC || op == OPANICN)
+			fmtprint(&fmt, "%%!");
+		on = syslook("printf", 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 == OPANIC || op == OPANICN)
+			r = mkcall("panicl", T, nil);
+		else
+			r = nod(OEMPTY, N, N);
+		typecheck(&r, Etop);
+		walkexpr(&r, init);
+		r->ninit = calls;
+	}
 	return r;
 }
 
diff --git a/src/pkg/runtime/print.c b/src/pkg/runtime/print.c
index 68a9f1e0a7..1214fed51d 100644
--- a/src/pkg/runtime/print.c
+++ b/src/pkg/runtime/print.c
@@ -6,6 +6,8 @@
 
 //static Lock debuglock;
 
+static void vprintf(int8*, byte*);
+
 void
 dump(byte *p, int32 n)
 {
@@ -29,18 +31,35 @@ prints(int8 *s)
 	write(fd, s, findnull((byte*)s));
 }
 
-// Very simple printf.  Only for debugging prints.
-// Do not add to this without checking with Rob.
+#pragma textflag 7
 void
 printf(int8 *s, ...)
+{
+	byte *arg;
+
+	arg = (byte*)(&s+1);
+	vprintf(s, arg);
+}
+
+static byte*
+vrnd(byte *p, int32 x)
+{
+	if((uint32)(uintptr)p&(x-1))
+		p += x - ((uint32)(uintptr)p&(x-1));
+	return p;
+}
+
+// Very simple printf.  Only for debugging prints.
+// Do not add to this without checking with Rob.
+static void
+vprintf(int8 *s, byte *arg)
 {
 	int8 *p, *lp;
-	byte *arg, *narg;
+	byte *narg;
 
 //	lock(&debuglock);
 
 	lp = p = s;
-	arg = (byte*)(&s+1);
 	for(; *p; p++) {
 		if(*p != '%')
 			continue;
@@ -49,40 +68,58 @@ printf(int8 *s, ...)
 		p++;
 		narg = nil;
 		switch(*p) {
+		case 't':
+			narg = arg + 1;
+			break;
 		case 'd':	// 32-bit
 		case 'x':
+			arg = vrnd(arg, 4);
 			narg = arg + 4;
 			break;
 		case 'D':	// 64-bit
+		case 'U':
 		case 'X':
-			if(sizeof(uintptr) == 8 && ((uint32)(uint64)arg)&4)
-				arg += 4;
+		case 'f':
+			arg = vrnd(arg, sizeof(uintptr));
 			narg = arg + 8;
 			break;
 		case 'p':	// pointer-sized
 		case 's':
-			if(sizeof(uintptr) == 8 && ((uint32)(uint64)arg)&4)
-				arg += 4;
+			arg = vrnd(arg, sizeof(uintptr));
 			narg = arg + sizeof(uintptr);
 			break;
 		case 'S':	// pointer-aligned but bigger
-			if(sizeof(uintptr) == 8 && ((uint32)(uint64)arg)&4)
-				arg += 4;
+			arg = vrnd(arg, sizeof(uintptr));
 			narg = arg + sizeof(String);
 			break;
+		case 'a':	// pointer-aligned but bigger
+			arg = vrnd(arg, sizeof(uintptr));
+			narg = arg + sizeof(Slice);
+			break;
+		case 'i':	// pointer-aligned but bigger
+		case 'e':
+			arg = vrnd(arg, sizeof(uintptr));
+			narg = arg + sizeof(Eface);
+			break;
 		}
 		switch(*p) {
+		case 'a':
+			·printslice(*(Slice*)arg);
+			break;
 		case 'd':
 			·printint(*(int32*)arg);
 			break;
 		case 'D':
 			·printint(*(int64*)arg);
 			break;
-		case 'x':
-			·printhex(*(uint32*)arg);
+		case 'e':
+			·printeface(*(Eface*)arg);
 			break;
-		case 'X':
-			·printhex(*(uint64*)arg);
+		case 'f':
+			·printfloat(*(float64*)arg);
+			break;
+		case 'i':
+			·printiface(*(Iface*)arg);
 			break;
 		case 'p':
 			·printpointer(*(void**)arg);
@@ -93,6 +130,20 @@ printf(int8 *s, ...)
 		case 'S':
 			·printstring(*(String*)arg);
 			break;
+		case 't':
+			·printbool(*(bool*)arg);
+			break;
+		case 'U':
+			·printuint(*(uint64*)arg);
+			break;
+		case 'x':
+			·printhex(*(uint32*)arg);
+			break;
+		case 'X':
+			·printhex(*(uint64*)arg);
+			break;
+		case '!':
+			·panicl(-1);
 		}
 		arg = narg;
 		lp = p+1;
@@ -103,6 +154,14 @@ printf(int8 *s, ...)
 //	unlock(&debuglock);
 }
 
+void
+·printf(String s, ...)
+{
+	// Can assume s has terminating NUL because only
+	// the Go compiler generates calls to ·printf, using
+	// string constants, and all the string constants have NULs.
+	vprintf((int8*)s.str, (byte*)(&s+1));
+}
 
 void
 ·printpc(void *p)
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index d09975eef1..03b54fc264 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -487,6 +487,7 @@ void	runtime_printpointer(void*);
 void	runtime_printuint(uint64);
 void	runtime_printhex(uint64);
 void	runtime_printslice(Slice);
+void	·panicl(int32);
 
 /*
  * wrapped for go users
diff --git a/test/deferprint.go b/test/deferprint.go
new file mode 100644
index 0000000000..f1e75266f7
--- /dev/null
+++ b/test/deferprint.go
@@ -0,0 +1,14 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func main() {
+	defer println(42, true, false, true, 1.5, "world", (chan int)(nil), []int(nil), (map[string]int)(nil), (func())(nil), byte(255))
+	defer println(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
+//	defer panic("dead")
+	defer print("printing: ")
+}
diff --git a/test/golden.out b/test/golden.out
index 59a83e7a88..72719ab33e 100644
--- a/test/golden.out
+++ b/test/golden.out
@@ -25,6 +25,10 @@ throw: interface hash
 
 panic PC=xxx
 
+=========== ./deferprint.go
+printing: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
+42 true false true +1.500000e+000 world 0x0 [0/0]0x0 0x0 0x0 255
+
 =========== ./helloworld.go
 hello, world