diff --git a/src/cmd/compile/internal/gc/closure.go b/src/cmd/compile/internal/gc/closure.go
index e07ed4cd24..1f4bf969ad 100644
--- a/src/cmd/compile/internal/gc/closure.go
+++ b/src/cmd/compile/internal/gc/closure.go
@@ -76,7 +76,7 @@ func (p *noder) funcLit(expr *syntax.FuncLit) ir.Node {
 // function associated with the closure.
 // TODO: This creation of the named function should probably really be done in a
 // separate pass from type-checking.
-func typecheckclosure(clo ir.Node, top int) {
+func typecheckclosure(clo *ir.ClosureExpr, top int) {
 	fn := clo.Func()
 	// Set current associated iota value, so iota can be used inside
 	// function in ConstSpec, see issue #22344
@@ -327,13 +327,13 @@ func transformclosure(fn *ir.Func) {
 
 // hasemptycvars reports whether closure clo has an
 // empty list of captured vars.
-func hasemptycvars(clo ir.Node) bool {
+func hasemptycvars(clo *ir.ClosureExpr) bool {
 	return len(clo.Func().ClosureVars) == 0
 }
 
 // closuredebugruntimecheck applies boilerplate checks for debug flags
 // and compiling runtime
-func closuredebugruntimecheck(clo ir.Node) {
+func closuredebugruntimecheck(clo *ir.ClosureExpr) {
 	if base.Debug.Closure > 0 {
 		if clo.Esc() == EscHeap {
 			base.WarnfAt(clo.Pos(), "heap closure, captured vars = %v", clo.Func().ClosureVars)
@@ -349,7 +349,7 @@ func closuredebugruntimecheck(clo ir.Node) {
 // closureType returns the struct type used to hold all the information
 // needed in the closure for clo (clo must be a OCLOSURE node).
 // The address of a variable of the returned type can be cast to a func.
-func closureType(clo ir.Node) *types.Type {
+func closureType(clo *ir.ClosureExpr) *types.Type {
 	// Create closure in the form of a composite literal.
 	// supposing the closure captures an int i and a string s
 	// and has one float64 argument and no results,
diff --git a/src/cmd/compile/internal/gc/dcl.go b/src/cmd/compile/internal/gc/dcl.go
index bcd127b5f1..558bdbef92 100644
--- a/src/cmd/compile/internal/gc/dcl.go
+++ b/src/cmd/compile/internal/gc/dcl.go
@@ -892,6 +892,7 @@ func (c *nowritebarrierrecChecker) findExtraCalls(nn ir.Node) {
 	case ir.ONAME:
 		callee = arg.Name().Defn.(*ir.Func)
 	case ir.OCLOSURE:
+		arg := arg.(*ir.ClosureExpr)
 		callee = arg.Func()
 	default:
 		base.Fatalf("expected ONAME or OCLOSURE node, got %+v", arg)
diff --git a/src/cmd/compile/internal/gc/escape.go b/src/cmd/compile/internal/gc/escape.go
index 3351cfe968..6510dfc4b3 100644
--- a/src/cmd/compile/internal/gc/escape.go
+++ b/src/cmd/compile/internal/gc/escape.go
@@ -678,6 +678,7 @@ func (e *Escape) exprSkipInit(k EscHole, n ir.Node) {
 		}
 
 	case ir.OCLOSURE:
+		n := n.(*ir.ClosureExpr)
 		k = e.spill(k, n)
 
 		// Link addresses of captured variables to closure.
@@ -879,7 +880,7 @@ func (e *Escape) call(ks []EscHole, call, where ir.Node) {
 			case v.Op() == ir.ONAME && v.(*ir.Name).Class() == ir.PFUNC:
 				fn = v.(*ir.Name)
 			case v.Op() == ir.OCLOSURE:
-				fn = v.Func().Nname
+				fn = v.(*ir.ClosureExpr).Func().Nname
 			}
 		case ir.OCALLMETH:
 			fn = methodExprName(call.Left())
@@ -1883,7 +1884,7 @@ func heapAllocReason(n ir.Node) string {
 		return "too large for stack"
 	}
 
-	if n.Op() == ir.OCLOSURE && closureType(n).Size() >= maxImplicitStackVarSize {
+	if n.Op() == ir.OCLOSURE && closureType(n.(*ir.ClosureExpr)).Size() >= maxImplicitStackVarSize {
 		return "too large for stack"
 	}
 	if n.Op() == ir.OCALLPART && partialCallType(n.(*ir.CallPartExpr)).Size() >= maxImplicitStackVarSize {
diff --git a/src/cmd/compile/internal/gc/iimport.go b/src/cmd/compile/internal/gc/iimport.go
index 358fdef294..5f72cedb66 100644
--- a/src/cmd/compile/internal/gc/iimport.go
+++ b/src/cmd/compile/internal/gc/iimport.go
@@ -630,7 +630,7 @@ func (r *importReader) varExt(n ir.Node) {
 	r.symIdx(n.Sym())
 }
 
-func (r *importReader) funcExt(n ir.Node) {
+func (r *importReader) funcExt(n *ir.Name) {
 	r.linkname(n.Sym())
 	r.symIdx(n.Sym())
 
@@ -654,7 +654,7 @@ func (r *importReader) methExt(m *types.Field) {
 	if r.bool() {
 		m.SetNointerface(true)
 	}
-	r.funcExt(ir.AsNode(m.Nname))
+	r.funcExt(m.Nname.(*ir.Name))
 }
 
 func (r *importReader) linkname(s *types.Sym) {
diff --git a/src/cmd/compile/internal/gc/initorder.go b/src/cmd/compile/internal/gc/initorder.go
index 1b21d92f4b..c9c3361d3c 100644
--- a/src/cmd/compile/internal/gc/initorder.go
+++ b/src/cmd/compile/internal/gc/initorder.go
@@ -296,6 +296,7 @@ func (d *initDeps) visit(n ir.Node) {
 		}
 
 	case ir.OCLOSURE:
+		n := n.(*ir.ClosureExpr)
 		d.inspectList(n.Func().Body())
 
 	case ir.ODOTMETH, ir.OCALLPART:
diff --git a/src/cmd/compile/internal/gc/inl.go b/src/cmd/compile/internal/gc/inl.go
index fde4d6910a..fc020000c7 100644
--- a/src/cmd/compile/internal/gc/inl.go
+++ b/src/cmd/compile/internal/gc/inl.go
@@ -237,7 +237,7 @@ func caninl(fn *ir.Func) {
 
 	n.Func().Inl = &ir.Inline{
 		Cost: inlineMaxBudget - visitor.budget,
-		Dcl:  pruneUnusedAutos(n.Defn.Func().Dcl, &visitor),
+		Dcl:  pruneUnusedAutos(n.Defn.(*ir.Func).Func().Dcl, &visitor),
 		Body: ir.DeepCopyList(src.NoXPos, fn.Body().Slice()),
 	}
 
@@ -677,6 +677,7 @@ func inlCallee(fn ir.Node) *ir.Func {
 			return fn.Func()
 		}
 	case ir.OCLOSURE:
+		fn := fn.(*ir.ClosureExpr)
 		c := fn.Func()
 		caninl(c)
 		return c
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index 80b17ebbf8..94b4e0e674 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -270,9 +270,12 @@ func Main(archInit func(*Arch)) {
 	// before walk reaches a call of a closure.
 	timings.Start("fe", "xclosures")
 	for _, n := range Target.Decls {
-		if n.Op() == ir.ODCLFUNC && n.Func().OClosure != nil {
-			Curfn = n.(*ir.Func)
-			transformclosure(Curfn)
+		if n.Op() == ir.ODCLFUNC {
+			n := n.(*ir.Func)
+			if n.Func().OClosure != nil {
+				Curfn = n
+				transformclosure(n)
+			}
 		}
 	}
 
diff --git a/src/cmd/compile/internal/gc/scc.go b/src/cmd/compile/internal/gc/scc.go
index 6e63d5287a..8fe20a80fd 100644
--- a/src/cmd/compile/internal/gc/scc.go
+++ b/src/cmd/compile/internal/gc/scc.go
@@ -56,8 +56,11 @@ func visitBottomUp(list []ir.Node, analyze func(list []*ir.Func, recursive bool)
 	v.analyze = analyze
 	v.nodeID = make(map[*ir.Func]uint32)
 	for _, n := range list {
-		if n.Op() == ir.ODCLFUNC && !n.Func().IsHiddenClosure() {
-			v.visit(n.(*ir.Func))
+		if n.Op() == ir.ODCLFUNC {
+			n := n.(*ir.Func)
+			if !n.Func().IsHiddenClosure() {
+				v.visit(n)
+			}
 		}
 	}
 }
@@ -109,6 +112,7 @@ func (v *bottomUpVisitor) visit(n *ir.Func) uint32 {
 				}
 			}
 		case ir.OCLOSURE:
+			n := n.(*ir.ClosureExpr)
 			if m := v.visit(n.Func()); m < min {
 				min = m
 			}
diff --git a/src/cmd/compile/internal/gc/scope.go b/src/cmd/compile/internal/gc/scope.go
index fe4e1d185a..8dd44b1dd4 100644
--- a/src/cmd/compile/internal/gc/scope.go
+++ b/src/cmd/compile/internal/gc/scope.go
@@ -28,7 +28,7 @@ func findScope(marks []ir.Mark, pos src.XPos) ir.ScopeID {
 	return marks[i-1].Scope
 }
 
-func assembleScopes(fnsym *obj.LSym, fn ir.Node, dwarfVars []*dwarf.Var, varScopes []ir.ScopeID) []dwarf.Scope {
+func assembleScopes(fnsym *obj.LSym, fn *ir.Func, dwarfVars []*dwarf.Var, varScopes []ir.ScopeID) []dwarf.Scope {
 	// Initialize the DWARF scope tree based on lexical scopes.
 	dwarfScopes := make([]dwarf.Scope, 1+len(fn.Func().Parents))
 	for i, parent := range fn.Func().Parents {
diff --git a/src/cmd/compile/internal/gc/sinit.go b/src/cmd/compile/internal/gc/sinit.go
index 9ef2bd56eb..79c7215d4d 100644
--- a/src/cmd/compile/internal/gc/sinit.go
+++ b/src/cmd/compile/internal/gc/sinit.go
@@ -269,6 +269,7 @@ func (s *InitSchedule) staticassign(l *ir.Name, loff int64, r ir.Node, typ *type
 		break
 
 	case ir.OCLOSURE:
+		r := r.(*ir.ClosureExpr)
 		if hasemptycvars(r) {
 			if base.Debug.Closure > 0 {
 				base.WarnfAt(r.Pos(), "closure converted to global")
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index cc5df3ebae..bb658999e5 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -95,9 +95,12 @@ func TypecheckPackage() {
 	// because variables captured by value do not escape.
 	timings.Start("fe", "capturevars")
 	for _, n := range Target.Decls {
-		if n.Op() == ir.ODCLFUNC && n.Func().OClosure != nil {
-			Curfn = n.(*ir.Func)
-			capturevars(Curfn)
+		if n.Op() == ir.ODCLFUNC {
+			n := n.(*ir.Func)
+			if n.Func().OClosure != nil {
+				Curfn = n
+				capturevars(n)
+			}
 		}
 	}
 	capturevarscomplete = true
@@ -2078,6 +2081,7 @@ func typecheck1(n ir.Node, top int) (res ir.Node) {
 		return n
 
 	case ir.OCLOSURE:
+		n := n.(*ir.ClosureExpr)
 		typecheckclosure(n, top)
 		if n.Type() == nil {
 			return n
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index 5545dcb345..87f08f41c3 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -649,11 +649,12 @@ func walkexpr1(n ir.Node, init *ir.Nodes) ir.Node {
 			// transformclosure already did all preparation work.
 
 			// Prepend captured variables to argument list.
-			n.PtrList().Prepend(n.Left().Func().ClosureEnter.Slice()...)
-			n.Left().Func().ClosureEnter.Set(nil)
+			clo := n.Left().(*ir.ClosureExpr)
+			n.PtrList().Prepend(clo.Func().ClosureEnter.Slice()...)
+			clo.Func().ClosureEnter.Set(nil)
 
 			// Replace OCLOSURE with ONAME/PFUNC.
-			n.SetLeft(n.Left().Func().Nname)
+			n.SetLeft(clo.Func().Nname)
 
 			// Update type of OCALLFUNC node.
 			// Output arguments had not changed, but their offsets could.
diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
index 6f15645813..76bb35f971 100644
--- a/src/cmd/compile/internal/ir/fmt.go
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -1189,6 +1189,7 @@ func dumpNode(w io.Writer, n Node, depth int) {
 	case ODCLFUNC:
 		// Func has many fields we don't want to print.
 		// Bypass reflection and just print what we want.
+		n := n.(*Func)
 		fmt.Fprintf(w, "%+v", n.Op())
 		dumpNodeHeader(w, n)
 		fn := n.Func()
diff --git a/src/cmd/compile/internal/ir/func.go b/src/cmd/compile/internal/ir/func.go
index 8aa6daed6f..62ac5791d1 100644
--- a/src/cmd/compile/internal/ir/func.go
+++ b/src/cmd/compile/internal/ir/func.go
@@ -213,10 +213,21 @@ func (f *Func) SetWBPos(pos src.XPos) {
 
 // funcname returns the name (without the package) of the function n.
 func FuncName(n Node) string {
-	if n == nil || n.Func() == nil || n.Func().Nname == nil {
+	var f *Func
+	switch n := n.(type) {
+	case *Func:
+		f = n
+	case *Name:
+		f = n.Func()
+	case *CallPartExpr:
+		f = n.Func()
+	case *ClosureExpr:
+		f = n.Func()
+	}
+	if f == nil || f.Nname == nil {
 		return "<nil>"
 	}
-	return n.Func().Nname.Sym().Name
+	return f.Nname.Sym().Name
 }
 
 // pkgFuncName returns the name of the function referenced by n, with package prepended.
@@ -231,10 +242,19 @@ func PkgFuncName(n Node) string {
 	if n.Op() == ONAME {
 		s = n.Sym()
 	} else {
-		if n.Func() == nil || n.Func().Nname == nil {
+		var f *Func
+		switch n := n.(type) {
+		case *CallPartExpr:
+			f = n.Func()
+		case *ClosureExpr:
+			f = n.Func()
+		case *Func:
+			f = n
+		}
+		if f == nil || f.Nname == nil {
 			return "<nil>"
 		}
-		s = n.Func().Nname.Sym()
+		s = f.Nname.Sym()
 	}
 	pkg := s.Pkg