diff --git a/src/cmd/compile/internal/gc/const.go b/src/cmd/compile/internal/gc/const.go
index 8771d82cfa..9aa65f97b6 100644
--- a/src/cmd/compile/internal/gc/const.go
+++ b/src/cmd/compile/internal/gc/const.go
@@ -115,22 +115,12 @@ func convlit1(n ir.Node, t *types.Type, explicit bool, context func() string) ir
 		return n
 	}
 
-	if n.Op() == ir.OLITERAL || n.Op() == ir.ONIL {
-		// Can't always set n.Type directly on OLITERAL nodes.
-		// See discussion on CL 20813.
-		old := n
-		n = ir.Copy(old)
-		if old.Op() == ir.OLITERAL {
-			// Keep untyped constants in their original untyped syntax for error messages.
-			n.(ir.OrigNode).SetOrig(old)
-		}
-	}
-
 	// Nil is technically not a constant, so handle it specially.
 	if n.Type().Kind() == types.TNIL {
 		if n.Op() != ir.ONIL {
 			base.Fatalf("unexpected op: %v (%v)", n, n.Op())
 		}
+		n = ir.Copy(n)
 		if t == nil {
 			base.Errorf("use of untyped nil")
 			n.SetDiag(true)
@@ -158,10 +148,11 @@ func convlit1(n ir.Node, t *types.Type, explicit bool, context func() string) ir
 	case ir.OLITERAL:
 		v := convertVal(n.Val(), t, explicit)
 		if v.Kind() == constant.Unknown {
+			n = ir.NewConstExpr(n.Val(), n)
 			break
 		}
+		n = ir.NewConstExpr(v, n)
 		n.SetType(t)
-		n.SetVal(v)
 		return n
 
 	case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT, ir.OREAL, ir.OIMAG:
@@ -541,8 +532,9 @@ func evalConst(n ir.Node) ir.Node {
 					i2++
 				}
 
-				nl := origConst(s[i], constant.MakeString(strings.Join(strs, "")))
-				nl.(ir.OrigNode).SetOrig(nl) // it's bigger than just s[i]
+				nl := ir.Copy(n)
+				nl.PtrList().Set(s[i:i2])
+				nl = origConst(nl, constant.MakeString(strings.Join(strs, "")))
 				newList = append(newList, nl)
 				i = i2 - 1
 			} else {
@@ -645,12 +637,7 @@ func origConst(n ir.Node, v constant.Value) ir.Node {
 		return n
 	}
 
-	orig := n
-	n = ir.NodAt(orig.Pos(), ir.OLITERAL, nil, nil)
-	n.(ir.OrigNode).SetOrig(orig)
-	n.SetType(orig.Type())
-	n.SetVal(v)
-	return n
+	return ir.NewConstExpr(v, n)
 }
 
 func origBoolConst(n ir.Node, v bool) ir.Node {
diff --git a/src/cmd/compile/internal/ir/expr.go b/src/cmd/compile/internal/ir/expr.go
index 2a7211cfda..412b7a18f0 100644
--- a/src/cmd/compile/internal/ir/expr.go
+++ b/src/cmd/compile/internal/ir/expr.go
@@ -9,6 +9,7 @@ import (
 	"cmd/compile/internal/types"
 	"cmd/internal/src"
 	"fmt"
+	"go/constant"
 )
 
 // A miniStmt is a miniNode with extra fields common to expressions.
@@ -300,6 +301,30 @@ func (n *CompLitExpr) SetOp(op Op) {
 	}
 }
 
+type ConstExpr struct {
+	miniExpr
+	val  constant.Value
+	orig Node
+}
+
+func NewConstExpr(val constant.Value, orig Node) Node {
+	n := &ConstExpr{orig: orig, val: val}
+	n.op = OLITERAL
+	n.pos = orig.Pos()
+	n.SetType(orig.Type())
+	n.SetTypecheck(orig.Typecheck())
+	n.SetDiag(orig.Diag())
+	return n
+}
+
+func (n *ConstExpr) String() string                { return fmt.Sprint(n) }
+func (n *ConstExpr) Format(s fmt.State, verb rune) { FmtNode(n, s, verb) }
+func (n *ConstExpr) rawCopy() Node                 { c := *n; return &c }
+func (n *ConstExpr) Sym() *types.Sym               { return n.orig.Sym() }
+func (n *ConstExpr) Orig() Node                    { return n.orig }
+func (n *ConstExpr) SetOrig(orig Node)             { n.orig = orig }
+func (n *ConstExpr) Val() constant.Value           { return n.val }
+
 // A ConvExpr is a conversion Type(X).
 // It may end up being a value or a type.
 type ConvExpr struct {