diff --git a/src/go/types/call.go b/src/go/types/call.go
index 2fa29dd439..98a8fda9d1 100644
--- a/src/go/types/call.go
+++ b/src/go/types/call.go
@@ -112,7 +112,7 @@ func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
 					break
 				}
 				if t := asInterface(T); t != nil {
-					if t.IsConstraint() {
+					if !t.IsMethodSet() {
 						check.errorf(call, _Todo, "cannot use interface %s in conversion (contains type list or is comparable)", T)
 						break
 					}
diff --git a/src/go/types/decl.go b/src/go/types/decl.go
index d0809f5a6e..3c68bbfb20 100644
--- a/src/go/types/decl.go
+++ b/src/go/types/decl.go
@@ -586,7 +586,7 @@ func (check *Checker) isImportedConstraint(typ Type) bool {
 		return false
 	}
 	u, _ := named.under().(*Interface)
-	return u != nil && u.IsConstraint()
+	return u != nil && !u.IsMethodSet()
 }
 
 func (check *Checker) typeDecl(obj *TypeName, tdecl *ast.TypeSpec, def *Named) {
diff --git a/src/go/types/interface.go b/src/go/types/interface.go
index ccea1f6dcc..866a3427ca 100644
--- a/src/go/types/interface.go
+++ b/src/go/types/interface.go
@@ -106,12 +106,7 @@ func (t *Interface) IsComparable() bool { return t.typeSet().IsComparable() }
 
 // IsMethodSet reports whether the interface t is fully described by its method
 // set.
-func (t *Interface) IsMethodSet() bool { return !t.typeSet().IsConstraint() }
-
-// IsConstraint reports whether interface t is not just a method set.
-//
-// TODO(rfindley): remove this method.
-func (t *Interface) IsConstraint() bool { return t.typeSet().IsConstraint() }
+func (t *Interface) IsMethodSet() bool { return t.typeSet().IsMethodSet() }
 
 // Complete computes the interface's type set. It must be called by users of
 // NewInterfaceType and NewInterface after the interface's embedded types are
diff --git a/src/go/types/signature.go b/src/go/types/signature.go
index c26437afe4..9bb6ec2f4f 100644
--- a/src/go/types/signature.go
+++ b/src/go/types/signature.go
@@ -82,15 +82,9 @@ func (s *Signature) Recv() *Var { return s.recv }
 // TypeParams returns the type parameters of signature s, or nil.
 func (s *Signature) TypeParams() *TypeParamList { return s.tparams }
 
-// SetTypeParams sets the type parameters of signature s.
-func (s *Signature) SetTypeParams(tparams []*TypeParam) { s.tparams = bindTParams(tparams) }
-
 // RecvTypeParams returns the receiver type parameters of signature s, or nil.
 func (s *Signature) RecvTypeParams() *TypeParamList { return s.rparams }
 
-// SetRecvTypeParams sets the receiver type params of signature s.
-func (s *Signature) SetRecvTypeParams(rparams []*TypeParam) { s.rparams = bindTParams(rparams) }
-
 // Params returns the parameters of signature s, or nil.
 func (s *Signature) Params() *Tuple { return s.params }
 
diff --git a/src/go/types/typeset.go b/src/go/types/typeset.go
index 3e59155e5c..b447799862 100644
--- a/src/go/types/typeset.go
+++ b/src/go/types/typeset.go
@@ -28,8 +28,8 @@ func (s *_TypeSet) IsEmpty() bool { return s.terms.isEmpty() }
 // IsAll reports whether type set s is the set of all types (corresponding to the empty interface).
 func (s *_TypeSet) IsAll() bool { return !s.comparable && len(s.methods) == 0 && s.terms.isAll() }
 
-// IsConstraint reports whether type set s is not just a set of methods.
-func (s *_TypeSet) IsConstraint() bool { return s.comparable || !s.terms.isAll() }
+// IsMethodSet reports whether the interface t is fully described by its method set.
+func (s *_TypeSet) IsMethodSet() bool { return !s.comparable && s.terms.isAll() }
 
 // IsComparable reports whether each type in the set is comparable.
 func (s *_TypeSet) IsComparable() bool {
diff --git a/src/go/types/typexpr.go b/src/go/types/typexpr.go
index 505c639444..c4e4bc3dfe 100644
--- a/src/go/types/typexpr.go
+++ b/src/go/types/typexpr.go
@@ -139,7 +139,7 @@ func (check *Checker) varType(e ast.Expr) Type {
 	check.later(func() {
 		if t := asInterface(typ); t != nil {
 			tset := computeInterfaceTypeSet(check, e.Pos(), t) // TODO(gri) is this the correct position?
-			if tset.IsConstraint() {
+			if !tset.IsMethodSet() {
 				if tset.comparable {
 					check.softErrorf(e, _Todo, "interface is (or embeds) comparable")
 				} else {