runtime: convert interface routines from C to Go.

LGTM=dvyukov
R=golang-codereviews, dave, bradfitz, dvyukov, khr
CC=golang-codereviews
https://codereview.appspot.com/98510044

10 files changed, 535 insertions, 390 deletions

diff --git a/src/cmd/api/goapi.go b/src/cmd/api/goapi.go
index fe3c257a5..38bf9592f 100644
--- a/src/cmd/api/goapi.go
+++ b/src/cmd/api/goapi.go
@@ -378,7 +378,7 @@ func (w *Walker) parseFile(dir, file string) (*ast.File, error) {
 	}
 	if w.context != nil && file == fmt.Sprintf("zruntime_defs_%s_%s.go", w.context.GOOS, w.context.GOARCH) {
 		// Just enough to keep the api checker happy.
-		src := "package runtime; type maptype struct{}; type _type struct{}; type alg struct{}; type mspan struct{}; type m struct{}; type lock struct{}; type slicetype struct{}; type iface struct{}; type eface struct{}"
+		src := "package runtime; type maptype struct{}; type _type struct{}; type alg struct{}; type mspan struct{}; type m struct{}; type lock struct{}; type slicetype struct{}; type iface struct{}; type eface struct{}; type interfacetype struct{}; type itab struct{}"
 		f, err = parser.ParseFile(fset, filename, src, 0)
 		if err != nil {
 			log.Fatalf("incorrect generated file: %s", err)
diff --git a/src/pkg/reflect/asm_386.s b/src/pkg/reflect/asm_386.s
index 18b348adc..a53862408 100644
--- a/src/pkg/reflect/asm_386.s
+++ b/src/pkg/reflect/asm_386.s
@@ -46,3 +46,9 @@ TEXT ·maplen(SB),NOSPLIT,$0-0
 	JMP	runtime·reflect_maplen(SB)
 TEXT ·ismapkey(SB),NOSPLIT,$0-0
 	JMP	runtime·reflect_ismapkey(SB)
+TEXT ·ifaceE2I(SB),NOSPLIT,$0-0
+	JMP	runtime·reflect_ifaceE2I(SB)
+TEXT ·unsafe_New(SB),NOSPLIT,$0-0
+	JMP	runtime·newobject(SB)
+TEXT ·unsafe_NewArray(SB),NOSPLIT,$0-0
+	JMP	runtime·newarray(SB)
diff --git a/src/pkg/reflect/asm_amd64.s b/src/pkg/reflect/asm_amd64.s
index 9a9eed02a..12a8879b7 100644
--- a/src/pkg/reflect/asm_amd64.s
+++ b/src/pkg/reflect/asm_amd64.s
@@ -46,3 +46,9 @@ TEXT ·maplen(SB),NOSPLIT,$0-0
 	JMP	runtime·reflect_maplen(SB)
 TEXT ·ismapkey(SB),NOSPLIT,$0-0
 	JMP	runtime·reflect_ismapkey(SB)
+TEXT ·ifaceE2I(SB),NOSPLIT,$0-0
+	JMP	runtime·reflect_ifaceE2I(SB)
+TEXT ·unsafe_New(SB),NOSPLIT,$0-0
+	JMP	runtime·newobject(SB)
+TEXT ·unsafe_NewArray(SB),NOSPLIT,$0-0
+	JMP	runtime·newarray(SB)
diff --git a/src/pkg/reflect/asm_amd64p32.s b/src/pkg/reflect/asm_amd64p32.s
index 18b348adc..a53862408 100644
--- a/src/pkg/reflect/asm_amd64p32.s
+++ b/src/pkg/reflect/asm_amd64p32.s
@@ -46,3 +46,9 @@ TEXT ·maplen(SB),NOSPLIT,$0-0
 	JMP	runtime·reflect_maplen(SB)
 TEXT ·ismapkey(SB),NOSPLIT,$0-0
 	JMP	runtime·reflect_ismapkey(SB)
+TEXT ·ifaceE2I(SB),NOSPLIT,$0-0
+	JMP	runtime·reflect_ifaceE2I(SB)
+TEXT ·unsafe_New(SB),NOSPLIT,$0-0
+	JMP	runtime·newobject(SB)
+TEXT ·unsafe_NewArray(SB),NOSPLIT,$0-0
+	JMP	runtime·newarray(SB)
diff --git a/src/pkg/reflect/asm_arm.s b/src/pkg/reflect/asm_arm.s
index 1db6b9b9d..69e4ab488 100644
--- a/src/pkg/reflect/asm_arm.s
+++ b/src/pkg/reflect/asm_arm.s
@@ -46,3 +46,9 @@ TEXT ·maplen(SB),NOSPLIT,$-4-0
 	B	runtime·reflect_maplen(SB)
 TEXT ·ismapkey(SB),NOSPLIT,$-4-0
 	B	runtime·reflect_ismapkey(SB)
+TEXT ·ifaceE2I(SB),NOSPLIT,$0-0
+	B	runtime·reflect_ifaceE2I(SB)
+TEXT ·unsafe_New(SB),NOSPLIT,$0-0
+	B	runtime·newobject(SB)
+TEXT ·unsafe_NewArray(SB),NOSPLIT,$0-0
+	B	runtime·newarray(SB)
diff --git a/src/pkg/runtime/alg.goc b/src/pkg/runtime/alg.goc
index 70c877ebb..6207ae526 100644
--- a/src/pkg/runtime/alg.goc
+++ b/src/pkg/runtime/alg.goc
@@ -308,6 +308,7 @@ runtime·nilintercopy(uintptr s, void *a, void *b)
 }
 
 extern uintptr runtime·nohashcode;
+extern uintptr runtime·noequalcode;
 
 void
 runtime·noequal(bool *eq, uintptr s, void *a, void *b)
@@ -371,6 +372,8 @@ void
 runtime·hashinit(void)
 {
 	runtime·nohashcode = (uintptr)runtime·nohash;
+	runtime·noequalcode = (uintptr)runtime·noequal;
+
         if(NaCl)
                 return;
 
diff --git a/src/pkg/runtime/iface.go b/src/pkg/runtime/iface.go
new file mode 100644
index 000000000..d3428e5a9
--- /dev/null
+++ b/src/pkg/runtime/iface.go
@@ -0,0 +1,469 @@
+// Copyright 2014 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 runtime
+
+import (
+	"unsafe"
+)
+
+const (
+	hashSize = 1009
+)
+
+var (
+	ifaceLock lock // lock for accessing hash
+	hash      [hashSize]*itab
+)
+
+// fInterface is our standard non-empty interface.  We use it instead
+// of interface{f()} in function prototypes because gofmt insists on
+// putting lots of newlines in the otherwise concise interface{f()}.
+type fInterface interface {
+	f()
+}
+
+func getitab(inter *interfacetype, typ *_type, canfail bool) *itab {
+	if len(inter.mhdr) == 0 {
+		gothrow("internal error - misuse of itab")
+	}
+
+	// easy case
+	x := typ.x
+	if x == nil {
+		if canfail {
+			return nil
+		}
+		i := (*imethod)(add(unsafe.Pointer(inter), unsafe.Sizeof(interfacetype{})))
+		panic(&TypeAssertionError{"", *typ._string, *inter.typ._string, *i.name})
+	}
+
+	// compiler has provided some good hash codes for us.
+	h := inter.typ.hash
+	h += 17 * typ.hash
+	// TODO(rsc): h += 23 * x.mhash ?
+	h %= hashSize
+
+	// look twice - once without lock, once with.
+	// common case will be no lock contention.
+	var m *itab
+	var locked int
+	for locked = 0; locked < 2; locked++ {
+		if locked != 0 {
+			golock(&ifaceLock)
+		}
+		for m = (*itab)(goatomicloadp(unsafe.Pointer(&hash[h]))); m != nil; m = m.link {
+			if m.inter == inter && m._type == typ {
+				if m.bad != 0 {
+					m = nil
+					if !canfail {
+						// this can only happen if the conversion
+						// was already done once using the , ok form
+						// and we have a cached negative result.
+						// the cached result doesn't record which
+						// interface function was missing, so jump
+						// down to the interface check, which will
+						// do more work but give a better error.
+						goto search
+					}
+				}
+				if locked != 0 {
+					gounlock(&ifaceLock)
+				}
+				return m
+			}
+		}
+	}
+
+	m = (*itab)(gopersistentalloc(unsafe.Sizeof(itab{}) + uintptr(len(inter.mhdr))*ptrSize))
+	m.inter = inter
+	m._type = typ
+
+search:
+	// both inter and typ have method sorted by name,
+	// and interface names are unique,
+	// so can iterate over both in lock step;
+	// the loop is O(ni+nt) not O(ni*nt).
+	ni := len(inter.mhdr)
+	nt := len(x.mhdr)
+	j := 0
+	for k := 0; k < ni; k++ {
+		i := (*imethod)(add(unsafe.Pointer(inter), unsafe.Sizeof(interfacetype{})+uintptr(k)*unsafe.Sizeof(imethod{})))
+		iname := i.name
+		ipkgpath := i.pkgpath
+		itype := i._type
+		for ; j < nt; j++ {
+			t := (*method)(add(unsafe.Pointer(x), unsafe.Sizeof(uncommontype{})+uintptr(j)*unsafe.Sizeof(method{})))
+			if t.mtyp == itype && t.name == iname && t.pkgpath == ipkgpath {
+				if m != nil {
+					f := (*func())(add(unsafe.Pointer(m), unsafe.Sizeof(itab{})+uintptr(k)*ptrSize))
+					*f = t.ifn
+				}
+				goto nextimethod
+			}
+		}
+		// didn't find method
+		if !canfail {
+			if locked != 0 {
+				gounlock(&ifaceLock)
+			}
+			panic(&TypeAssertionError{"", *typ._string, *inter.typ._string, *iname})
+		}
+		m.bad = 1
+		break
+	nextimethod:
+	}
+	if locked == 0 {
+		gothrow("invalid itab locking")
+	}
+	m.link = hash[h]
+	goatomicstorep(unsafe.Pointer(&hash[h]), unsafe.Pointer(m))
+	gounlock(&ifaceLock)
+	if m.bad != 0 {
+		return nil
+	}
+	return m
+}
+
+func typ2Itab(t *_type, inter *interfacetype, cache **itab) *itab {
+	tab := getitab(inter, t, false)
+	goatomicstorep(unsafe.Pointer(cache), unsafe.Pointer(tab))
+	return tab
+}
+
+func convT2E(t *_type, elem unsafe.Pointer) (e interface{}) {
+	size := uintptr(t.size)
+	ep := (*eface)(unsafe.Pointer(&e))
+	if size <= ptrSize {
+		ep._type = t
+		memmove(unsafe.Pointer(&ep.data), elem, size)
+	} else {
+		x := newobject(t)
+		// TODO: We allocate a zeroed object only to overwrite it with
+		// actual data.  Figure out how to avoid zeroing.  Also below in convT2I.
+		memmove(x, elem, size)
+		ep._type = t
+		ep.data = x
+	}
+	return
+}
+
+func convT2I(t *_type, inter *interfacetype, cache **itab, elem unsafe.Pointer) (i fInterface) {
+	tab := (*itab)(goatomicloadp(unsafe.Pointer(cache)))
+	if tab == nil {
+		tab = getitab(inter, t, false)
+		goatomicstorep(unsafe.Pointer(cache), unsafe.Pointer(tab))
+	}
+	size := uintptr(t.size)
+	pi := (*iface)(unsafe.Pointer(&i))
+	if size <= ptrSize {
+		pi.tab = tab
+		memmove(unsafe.Pointer(&pi.data), elem, size)
+	} else {
+		x := newobject(t)
+		memmove(x, elem, size)
+		pi.tab = tab
+		pi.data = x
+	}
+	return
+}
+
+// TODO: give these routines a pointer to the result area instead of writing
+// extra data in the outargs section.  Then we can get rid of go:nosplit.
+//go:nosplit
+func assertI2T(t *_type, i fInterface) (r struct{}) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		panic(&TypeAssertionError{"", "", *t._string, ""})
+	}
+	if tab._type != t {
+		panic(&TypeAssertionError{*tab.inter.typ._string, *tab._type._string, *t._string, ""})
+	}
+	size := uintptr(t.size)
+	if size <= ptrSize {
+		memmove(unsafe.Pointer(&r), unsafe.Pointer(&ip.data), size)
+	} else {
+		memmove(unsafe.Pointer(&r), ip.data, size)
+	}
+	return
+}
+
+//go:nosplit
+func assertI2T2(t *_type, i fInterface) (r byte) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	size := uintptr(t.size)
+	ok := (*bool)(add(unsafe.Pointer(&r), size))
+	tab := ip.tab
+	if tab == nil || tab._type != t {
+		*ok = false
+		memclr(unsafe.Pointer(&r), size)
+		return
+	}
+	*ok = true
+	if size <= ptrSize {
+		memmove(unsafe.Pointer(&r), unsafe.Pointer(&ip.data), size)
+	} else {
+		memmove(unsafe.Pointer(&r), ip.data, size)
+	}
+	return
+}
+
+func assertI2TOK(t *_type, i fInterface) bool {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	return tab != nil && tab._type == t
+}
+
+//go:nosplit
+func assertE2T(t *_type, e interface{}) (r struct{}) {
+	ep := (*eface)(unsafe.Pointer(&e))
+	if ep._type == nil {
+		panic(&TypeAssertionError{"", "", *t._string, ""})
+	}
+	if ep._type != t {
+		panic(&TypeAssertionError{"", *ep._type._string, *t._string, ""})
+	}
+	size := uintptr(t.size)
+	if size <= ptrSize {
+		memmove(unsafe.Pointer(&r), unsafe.Pointer(&ep.data), size)
+	} else {
+		memmove(unsafe.Pointer(&r), ep.data, size)
+	}
+	return
+}
+
+//go:nosplit
+func assertE2T2(t *_type, e interface{}) (r byte) {
+	ep := (*eface)(unsafe.Pointer(&e))
+	size := uintptr(t.size)
+	ok := (*bool)(add(unsafe.Pointer(&r), size))
+	if ep._type != t {
+		*ok = false
+		memclr(unsafe.Pointer(&r), size)
+		return
+	}
+	*ok = true
+	if size <= ptrSize {
+		memmove(unsafe.Pointer(&r), unsafe.Pointer(&ep.data), size)
+	} else {
+		memmove(unsafe.Pointer(&r), ep.data, size)
+	}
+	return
+}
+
+func assertE2TOK(t *_type, e interface{}) bool {
+	ep := (*eface)(unsafe.Pointer(&e))
+	return t == ep._type
+}
+
+func convI2E(i fInterface) (r interface{}) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		return
+	}
+	rp := (*eface)(unsafe.Pointer(&r))
+	rp._type = tab._type
+	rp.data = ip.data
+	return
+}
+
+func assertI2E(inter *interfacetype, i fInterface) (r interface{}) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		// explicit conversions require non-nil interface value.
+		panic(&TypeAssertionError{"", "", *inter.typ._string, ""})
+	}
+	rp := (*eface)(unsafe.Pointer(&r))
+	rp._type = tab._type
+	rp.data = ip.data
+	return
+}
+
+func assertI2E2(inter *interfacetype, i fInterface) (r interface{}, ok bool) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		return
+	}
+	rp := (*eface)(unsafe.Pointer(&r))
+	rp._type = tab._type
+	rp.data = ip.data
+	ok = true
+	return
+}
+
+func convI2I(inter *interfacetype, i fInterface) (r fInterface) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		return
+	}
+	rp := (*iface)(unsafe.Pointer(&r))
+	if tab.inter == inter {
+		rp.tab = tab
+		rp.data = ip.data
+		return
+	}
+	rp.tab = getitab(inter, tab._type, false)
+	rp.data = ip.data
+	return
+}
+
+func assertI2I(inter *interfacetype, i fInterface) (r fInterface) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		// explicit conversions require non-nil interface value.
+		panic(&TypeAssertionError{"", "", *inter.typ._string, ""})
+	}
+	rp := (*iface)(unsafe.Pointer(&r))
+	if tab.inter == inter {
+		rp.tab = tab
+		rp.data = ip.data
+		return
+	}
+	rp.tab = getitab(inter, tab._type, false)
+	rp.data = ip.data
+	return
+}
+
+func assertI2I2(inter *interfacetype, i fInterface) (r fInterface, ok bool) {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		return
+	}
+	rp := (*iface)(unsafe.Pointer(&r))
+	if tab.inter == inter {
+		rp.tab = tab
+		rp.data = ip.data
+		ok = true
+		return
+	}
+	tab = getitab(inter, tab._type, true)
+	if tab == nil {
+		rp.data = nil
+		rp.tab = nil
+		ok = false
+		return
+	}
+	rp.tab = tab
+	rp.data = ip.data
+	ok = true
+	return
+}
+
+func assertE2I(inter *interfacetype, e interface{}) (r fInterface) {
+	ep := (*eface)(unsafe.Pointer(&e))
+	t := ep._type
+	if t == nil {
+		// explicit conversions require non-nil interface value.
+		panic(&TypeAssertionError{"", "", *inter.typ._string, ""})
+	}
+	rp := (*iface)(unsafe.Pointer(&r))
+	rp.tab = getitab(inter, t, false)
+	rp.data = ep.data
+	return
+}
+
+func assertE2I2(inter *interfacetype, e interface{}) (r fInterface, ok bool) {
+	ep := (*eface)(unsafe.Pointer(&e))
+	t := ep._type
+	if t == nil {
+		return
+	}
+	tab := getitab(inter, t, true)
+	if tab == nil {
+		return
+	}
+	rp := (*iface)(unsafe.Pointer(&r))
+	rp.tab = tab
+	rp.data = ep.data
+	ok = true
+	return
+}
+
+func reflect_ifaceE2I(inter *interfacetype, e interface{}, dst *fInterface) {
+	*dst = assertE2I(inter, e)
+}
+
+func assertE2E(inter *interfacetype, e interface{}) interface{} {
+	ep := (*eface)(unsafe.Pointer(&e))
+	if ep._type == nil {
+		// explicit conversions require non-nil interface value.
+		panic(&TypeAssertionError{"", "", *inter.typ._string, ""})
+	}
+	return e
+}
+
+func assertE2E2(inter *interfacetype, e interface{}) (interface{}, bool) {
+	ep := (*eface)(unsafe.Pointer(&e))
+	if ep._type == nil {
+		return nil, false
+	}
+	return e, true
+}
+
+func efaceeq(e1 interface{}, e2 interface{}) bool {
+	p1 := (*eface)(unsafe.Pointer(&e1))
+	p2 := (*eface)(unsafe.Pointer(&e2))
+	t := p1._type
+	if t != p2._type {
+		return false
+	}
+	if t == nil {
+		return true
+	}
+
+	if *(*uintptr)(unsafe.Pointer(&t.alg.equal)) == noequalcode {
+		panic(errorString("comparing uncomparable type " + *t._string))
+	}
+	size := uintptr(t.size)
+	if size <= ptrSize {
+		return goeq(t.alg, unsafe.Pointer(&p1.data), unsafe.Pointer(&p2.data), size)
+	}
+	return goeq(t.alg, p1.data, p2.data, size)
+}
+
+func ifaceeq(i1 fInterface, i2 fInterface) bool {
+	p1 := (*iface)(unsafe.Pointer(&i1))
+	p2 := (*iface)(unsafe.Pointer(&i2))
+	tab := p1.tab
+	if tab != p2.tab {
+		return false
+	}
+	if tab == nil {
+		return true
+	}
+	t := tab._type
+	if *(*uintptr)(unsafe.Pointer(&t.alg.equal)) == noequalcode {
+		panic(errorString("comparing uncomparable type " + *t._string))
+	}
+	size := uintptr(t.size)
+	if size <= ptrSize {
+		return goeq(t.alg, unsafe.Pointer(&p1.data), unsafe.Pointer(&p2.data), size)
+	}
+	return goeq(t.alg, p1.data, p2.data, size)
+}
+
+func ifacethash(i fInterface) uint32 {
+	ip := (*iface)(unsafe.Pointer(&i))
+	tab := ip.tab
+	if tab == nil {
+		return 0
+	}
+	return tab._type.hash
+}
+
+func efacethash(e interface{}) uint32 {
+	ep := (*eface)(unsafe.Pointer(&e))
+	t := ep._type
+	if t == nil {
+		return 0
+	}
+	return t.hash
+}
diff --git a/src/pkg/runtime/iface.goc b/src/pkg/runtime/iface.goc
index 719d11588..a2e968faf 100644
--- a/src/pkg/runtime/iface.goc
+++ b/src/pkg/runtime/iface.goc
@@ -10,9 +10,10 @@ package runtime
 #include "malloc.h"
 #include "../../cmd/ld/textflag.h"
 
-static	Itab*	hash[1009];
-static	Lock	ifacelock;
+extern	Itab*	runtime·hash[1009];
+extern	Lock	runtime·ifaceLock;
 
+// TODO: delete this when no longer used (ifaceE2I2 is all that's left)
 static Itab*
 itab(InterfaceType *inter, Type *type, int32 canfail)
 {
@@ -45,14 +46,14 @@ itab(InterfaceType *inter, Type *type, int32 canfail)
 	h = inter->typ.hash;
 	h += 17 * type->hash;
 	// TODO(rsc): h += 23 * x->mhash ?
-	h %= nelem(hash);
+	h %= nelem(runtime·hash);
 
 	// look twice - once without lock, once with.
 	// common case will be no lock contention.
 	for(locked=0; locked<2; locked++) {
 		if(locked)
-			runtime·lock(&ifacelock);
-		for(m=runtime·atomicloadp(&hash[h]); m!=nil; m=m->link) {
+			runtime·lock(&runtime·ifaceLock);
+		for(m=runtime·atomicloadp(&runtime·hash[h]); m!=nil; m=m->link) {
 			if(m->inter == inter && m->type == type) {
 				if(m->bad) {
 					m = nil;
@@ -68,7 +69,7 @@ itab(InterfaceType *inter, Type *type, int32 canfail)
 					}
 				}
 				if(locked)
-					runtime·unlock(&ifacelock);
+					runtime·unlock(&runtime·ifaceLock);
 				return m;
 			}
 		}
@@ -101,7 +102,7 @@ search:
 						nil, type->string, inter->typ.string,
 						iname, &err);
 					if(locked)
-						runtime·unlock(&ifacelock);
+						runtime·unlock(&runtime·ifaceLock);
 					runtime·panic(err);
 					return nil;	// not reached
 				}
@@ -118,9 +119,9 @@ search:
 out:
 	if(!locked)
 		runtime·panicstring("invalid itab locking");
-	m->link = hash[h];
-	runtime·atomicstorep(&hash[h], m);
-	runtime·unlock(&ifacelock);
+	m->link = runtime·hash[h];
+	runtime·atomicstorep(&runtime·hash[h], m);
+	runtime·unlock(&runtime·ifaceLock);
 	if(m->bad)
 		return nil;
 	return m;
@@ -133,295 +134,16 @@ runtime·iterate_itabs(void (*callback)(Itab*))
 	int32 i;
 	Itab *tab;
 
-	for(i = 0; i < nelem(hash); i++) {
-		for(tab = hash[i]; tab != nil; tab = tab->link) {
+	for(i = 0; i < nelem(runtime·hash); i++) {
+		for(tab = runtime·hash[i]; tab != nil; tab = tab->link) {
 			callback(tab);
 		}
 	}
 }
 
-static void
-copyin(Type *t, void *src, void **dst)
-{
-	uintptr size;
-	void *p;
-	Alg *alg;
-
-	size = t->size;
-	alg = t->alg;
-
-	if(size <= sizeof(*dst))
-		alg->copy(size, dst, src);
-	else {
-		p = runtime·cnew(t);
-		alg->copy(size, p, src);
-		*dst = p;
-	}
-}
-
-static void
-copyout(Type *t, void **src, void *dst)
-{
-	uintptr size;
-	Alg *alg;
-
-	size = t->size;
-	alg = t->alg;
-
-	if(size <= sizeof(*src))
-		alg->copy(size, dst, src);
-	else
-		alg->copy(size, dst, *src);
-}
-
-#pragma textflag NOSPLIT
-func typ2Itab(t *Type, inter *InterfaceType, cache **Itab) (tab *Itab) {
-	tab = itab(inter, t, 0);
-	runtime·atomicstorep(cache, tab);
-}
-
-#pragma textflag NOSPLIT
-func convT2I(t *Type, inter *InterfaceType, cache **Itab, elem *byte) (ret Iface) {
-	Itab *tab;
-
-	tab = runtime·atomicloadp(cache);
-	if(!tab) {
-		tab = itab(inter, t, 0);
-		runtime·atomicstorep(cache, tab);
-	}
-	ret.tab = tab;
-	copyin(t, elem, &ret.data);
-}
-
-#pragma textflag NOSPLIT
-func convT2E(t *Type, elem *byte) (ret Eface) {
-	ret.type = t;
-	copyin(t, elem, &ret.data);
-}
-
-static void assertI2Tret(Type *t, Iface i, byte *ret);
-
-/*
- * NOTE: Cannot use 'func' here, because we have to declare
- * a return value, the only types we have are at least 1 byte large,
- * goc2c will zero the return value, and the actual return value
- * might have size 0 bytes, in which case the zeroing of the
- * 1 or more bytes would be wrong.
- * Using C lets us control (avoid) the initial zeroing.
- */
-#pragma textflag NOSPLIT
-void
-runtime·assertI2T(Type *t, Iface i, GoOutput retbase)
-{
-	assertI2Tret(t, i, (byte*)&retbase);
-}
-
-static void
-assertI2Tret(Type *t, Iface i, byte *ret)
-{
-	Itab *tab;
-	Eface err;
-
-	tab = i.tab;
-	if(tab == nil) {
-		runtime·newTypeAssertionError(
-			nil, nil, t->string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	if(tab->type != t) {
-		runtime·newTypeAssertionError(
-			tab->inter->typ.string, tab->type->string, t->string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	copyout(t, &i.data, ret);
-}
-
-#pragma textflag NOSPLIT
-func assertI2T2(t *Type, i Iface) (ret byte, ...) {
-	bool *ok;
-	int32 wid;
-
-	wid = t->size;
-	ok = (bool*)(&ret + wid);
-
-	if(i.tab == nil || i.tab->type != t) {
-		*ok = false;
-		runtime·memclr(&ret, wid);
-		return;
-	}
-
-	*ok = true;
-	copyout(t, &i.data, &ret);
-}
-
-func assertI2TOK(t *Type, i Iface) (ok bool) {
-	ok = i.tab!=nil && i.tab->type==t;
-}
-
-static void assertE2Tret(Type *t, Eface e, byte *ret);
-
-/*
- * NOTE: Cannot use 'func' here. See assertI2T above.
- */
-#pragma textflag NOSPLIT
-void
-runtime·assertE2T(Type *t, Eface e, GoOutput retbase)
-{
-	assertE2Tret(t, e, (byte*)&retbase);
-}
-
-static void
-assertE2Tret(Type *t, Eface e, byte *ret)
-{
-	Eface err;
-
-	if(e.type == nil) {
-		runtime·newTypeAssertionError(
-			nil, nil, t->string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	if(e.type != t) {
-		runtime·newTypeAssertionError(
-			nil, e.type->string, t->string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	copyout(t, &e.data, ret);
-}
-
-#pragma textflag NOSPLIT
-func assertE2T2(t *Type, e Eface) (ret byte, ...) {
-	bool *ok;
-	int32 wid;
-
-	wid = t->size;
-	ok = (bool*)(&ret + wid);
-
-	if(t != e.type) {
-		*ok = false;
-		runtime·memclr(&ret, wid);
-		return;
-	}
-
-	*ok = true;
-	copyout(t, &e.data, &ret);
-}
-
-func assertE2TOK(t *Type, e Eface) (ok bool) {
-	ok = t==e.type;
-}
-
-func convI2E(i Iface) (ret Eface) {
-	Itab *tab;
-
-	ret.data = i.data;
-	if((tab = i.tab) == nil)
-		ret.type = nil;
-	else
-		ret.type = tab->type;
-}
-
-func assertI2E(inter *InterfaceType, i Iface) (ret Eface) {
-	Itab *tab;
-	Eface err;
-
-	tab = i.tab;
-	if(tab == nil) {
-		// explicit conversions require non-nil interface value.
-		runtime·newTypeAssertionError(
-			nil, nil, inter->typ.string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	ret.data = i.data;
-	ret.type = tab->type;
-}
-
-func assertI2E2(inter *InterfaceType, i Iface) (ret Eface, ok bool) {
-	Itab *tab;
-
-	USED(inter);
-	tab = i.tab;
-	if(tab == nil) {
-		ret.type = nil;
-		ok = 0;
-	} else {
-		ret.type = tab->type;
-		ok = 1;
-	}
-	ret.data = i.data;
-}
-
-func convI2I(inter *InterfaceType, i Iface) (ret Iface) {
-	Itab *tab;
-
-	ret.data = i.data;
-	if((tab = i.tab) == nil)
-		ret.tab = nil;
-	else if(tab->inter == inter)
-		ret.tab = tab;
-	else
-		ret.tab = itab(inter, tab->type, 0);
-}
-
-void
-runtime·ifaceI2I(InterfaceType *inter, Iface i, Iface *ret)
-{
-	Itab *tab;
-	Eface err;
-
-	tab = i.tab;
-	if(tab == nil) {
-		// explicit conversions require non-nil interface value.
-		runtime·newTypeAssertionError(
-			nil, nil, inter->typ.string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	ret->data = i.data;
-	ret->tab = itab(inter, tab->type, 0);
-}
-
-func assertI2I(inter *InterfaceType, i Iface) (ret Iface) {
-	runtime·ifaceI2I(inter, i, &ret);
-}
-
-func assertI2I2(inter *InterfaceType, i Iface) (ret Iface, ok bool) {
-	Itab *tab;
-
-	tab = i.tab;
-	if(tab != nil && (tab->inter == inter || (tab = itab(inter, tab->type, 1)) != nil)) {
-		ret.data = i.data;
-		ret.tab = tab;
-		ok = 1;
-	} else {
-		ret.data = 0;
-		ret.tab = 0;
-		ok = 0;
-	}
-}
-
-void
-runtime·ifaceE2I(InterfaceType *inter, Eface e, Iface *ret)
-{
-	Type *t;
-	Eface err;
-
-	t = e.type;
-	if(t == nil) {
-		// explicit conversions require non-nil interface value.
-		runtime·newTypeAssertionError(
-			nil, nil, inter->typ.string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	ret->data = e.data;
-	ret->tab = itab(inter, t, 0);
-}
-
+// Still in C because it is called from C for finalizers.  This will
+// get converted to Go in a separate CL.  This is the last user of
+// the C version of itab().
 bool
 runtime·ifaceE2I2(InterfaceType *inter, Eface e, Iface *ret)
 {
@@ -432,49 +154,6 @@ runtime·ifaceE2I2(InterfaceType *inter, Eface e, Iface *ret)
 	return true;
 }
 
-func reflect·ifaceE2I(inter *InterfaceType, e Eface, dst *Iface) {
-	runtime·ifaceE2I(inter, e, dst);
-}
-
-func assertE2I(inter *InterfaceType, e Eface) (ret Iface) {
-	runtime·ifaceE2I(inter, e, &ret);
-}
-
-func assertE2I2(inter *InterfaceType, e Eface) (ret Iface, ok bool) {
-	if(e.type == nil) {
-		ok = 0;
-		ret.data = nil;
-		ret.tab = nil;
-	} else if((ret.tab = itab(inter, e.type, 1)) == nil) {
-		ok = 0;
-		ret.data = nil;
-	} else {
-		ok = 1;
-		ret.data = e.data;
-	}
-}
-
-func assertE2E(inter *InterfaceType, e Eface) (ret Eface) {
-	Type *t;
-	Eface err;
-
-	t = e.type;
-	if(t == nil) {
-		// explicit conversions require non-nil interface value.
-		runtime·newTypeAssertionError(
-			nil, nil, inter->typ.string,
-			nil, &err);
-		runtime·panic(err);
-	}
-	ret = e;
-}
-
-func assertE2E2(inter *InterfaceType, e Eface) (ret Eface, ok bool) {
-	USED(inter);
-	ret = e;
-	ok = e.type != nil;
-}
-
 static bool
 ifaceeq1(void *data1, void *data2, Type *t)
 {
@@ -520,54 +199,3 @@ runtime·efaceeq_c(Eface e1, Eface e2)
 		return true;
 	return ifaceeq1(e1.data, e2.data, e1.type);
 }
-
-func ifaceeq(i1 Iface, i2 Iface) (ret bool) {
-	ret = runtime·ifaceeq_c(i1, i2);
-}
-
-func efaceeq(e1 Eface, e2 Eface) (ret bool) {
-	ret = runtime·efaceeq_c(e1, e2);
-}
-
-func ifacethash(i1 Iface) (ret uint32) {
-	Itab *tab;
-
-	ret = 0;
-	tab = i1.tab;
-	if(tab != nil)
-		ret = tab->type->hash;
-}
-
-func efacethash(e1 Eface) (ret uint32) {
-	Type *t;
-
-	ret = 0;
-	t = e1.type;
-	if(t != nil)
-		ret = t->hash;
-}
-
-func reflect·unsafe_Typeof(e Eface) (ret Eface) {
-	if(e.type == nil) {
-		ret.type = nil;
-		ret.data = nil;
-	} else {
-		ret = *(Eface*)(e.type);
-	}
-}
-
-func reflect·unsafe_New(t *Type) (ret *byte) {
-	ret = runtime·cnew(t);
-}
-
-func reflect·unsafe_NewArray(t *Type, n int) (ret *byte) {
-	ret = runtime·cnewarray(t, n);
-}
-
-func reflect·typelinks() (ret Slice) {
-	extern Type *typelink[], *etypelink[];
-	static int32 first = 1;
-	ret.array = (byte*)typelink;
-	ret.len = etypelink - typelink;
-	ret.cap = ret.len;
-}
diff --git a/src/pkg/runtime/stubs.go b/src/pkg/runtime/stubs.go
index fee18f047..77eece943 100644
--- a/src/pkg/runtime/stubs.go
+++ b/src/pkg/runtime/stubs.go
@@ -72,6 +72,7 @@ var (
 
 // memclr clears n bytes starting at ptr.
 // in memclr_*.s
+//go:noescape
 func memclr(ptr unsafe.Pointer, n uintptr)
 
 func racemalloc(p unsafe.Pointer, size uintptr)
@@ -79,6 +80,7 @@ func tracealloc(p unsafe.Pointer, size uintptr, typ *_type)
 
 // memmove copies n bytes from "from" to "to".
 // in memmove_*.s
+//go:noescape
 func memmove(to unsafe.Pointer, from unsafe.Pointer, n uintptr)
 
 // in asm_*.s
@@ -124,8 +126,9 @@ var hashLoad = loadFactor
 //go:noescape
 func gomemeq(a, b unsafe.Pointer, size uintptr) bool
 
-// Code pointer for the nohash algorithm. Used for producing better error messages.
+// Code pointers for the nohash/noequal algorithms. Used for producing better error messages.
 var nohashcode uintptr
+var noequalcode uintptr
 
 // Go version of runtime.throw.
 // in panic.c
@@ -159,3 +162,7 @@ func noescape(p unsafe.Pointer) unsafe.Pointer {
 	x := uintptr(p)
 	return unsafe.Pointer(x ^ 0)
 }
+
+// gopersistentalloc allocates a permanent (not garbage collected)
+// memory region of size n.  Use wisely!
+func gopersistentalloc(n uintptr) unsafe.Pointer
diff --git a/src/pkg/runtime/stubs.goc b/src/pkg/runtime/stubs.goc
index 42a4bf143..8a043c63b 100644
--- a/src/pkg/runtime/stubs.goc
+++ b/src/pkg/runtime/stubs.goc
@@ -89,3 +89,17 @@ func GCMask(x Eface) (mask Slice) {
 	runtime·getgcmask(x.data, x.type, &mask.array, &mask.len);
 	mask.cap = mask.len;
 }
+
+#pragma textflag NOSPLIT
+func gopersistentalloc(size uintptr) (x *void) {
+	// TODO: used only for itabs for now.  Need to make &mstats.other_sys arg parameterized.
+	x = runtime·persistentalloc(size, 0, &mstats.other_sys);
+}
+
+#pragma textflag NOSPLIT
+func reflect·typelinks() (ret Slice) {
+        extern Type *typelink[], *etypelink[];
+        ret.array = (byte*)typelink;
+        ret.len = etypelink - typelink;
+        ret.cap = ret.len;
+}