func (n *miniNode) Sym() *types.Sym         { return nil }
func (n *miniNode) Val() constant.Value     { panic(n.no("Val")) }
func (n *miniNode) SetVal(v constant.Value) { panic(n.no("SetVal")) }
func (n *miniNode) NonNil() bool            { return false }

			tab.SetTypecheck(1)
			eqtype = ir.NewBinaryExpr(base.Pos, eq, tab, rtyp)
		} else {
			nonnil := ir.NewBinaryExpr(base.Pos, brcom(eq), typecheck.NodNil(), tab)
			match := ir.NewBinaryExpr(base.Pos, eq, itabType(tab), rtyp)
			eqtype = ir.NewLogicalExpr(base.Pos, andor, nonnil, match)
		}
		// Check for data equal.
		eqdata := ir.NewBinaryExpr(base.Pos, eq, ifaceData(n.Pos(), l, r.Type()), r)

		return s.newValue2(ssa.OpStringMake, n.Type(), ptr, len)
	case ir.OSTR2BYTESTMP:
		n := n.(*ir.ConvExpr)
		str := s.expr(n.X)
		ptr := s.newValue1(ssa.OpStringPtr, s.f.Config.Types.BytePtr, str)
		if !n.NonNil() {
			// We need to ensure []byte("") evaluates to []byte{}, and not []byte(nil).
			//
			// TODO(mdempsky): Investigate using "len != 0" instead of "ptr != nil".

	register("RecursivePanic3", RecursivePanic3)
	register("RecursivePanic4", RecursivePanic4)
	register("RecursivePanic5", RecursivePanic5)
	register("GoexitExit", GoexitExit)
	register("GoNil", GoNil)
	register("MainGoroutineID", MainGoroutineID)
	register("Breakpoint", Breakpoint)
	register("GoexitInPanic", GoexitInPanic)
	register("PanicAfterGoexit", PanicAfterGoexit)

// If pos.IsKnown(), it sets the source position of newly allocated Nodes to pos.
func DeepCopy(pos src.XPos, n Node) Node {
	var edit func(Node) Node
	edit = func(x Node) Node {
		switch x.Op() {
		case ONAME, ONONAME, OLITERAL, ONIL, OTYPE:
			return x
		}
		x = Copy(x)
		if pos.IsKnown() {
			x.SetPos(pos)
		}
		EditChildren(x, edit)
		return x
	}
	return edit(n)
}

		if loff != 0 || !types.Identical(typ, l.Type()) {
			dst = ir.NewNameOffsetExpr(base.Pos, l, loff, typ)
		}
		s.append(ir.NewAssignStmt(base.Pos, dst, typecheck.Conv(r, typ)))
		return true

	case ir.ONIL:
		return true

	case ir.OLITERAL:
		if ir.IsZero(r) {
			return true
		}
		staticdata.InitConst(l, loff, r, int(typ.Size()))
		return true

	case ir.OADDR:
		r := r.(*ir.AddrExpr)

		}
		return true
	case ir.OLITERAL, ir.ONIL:
		return true
	case ir.OCONVIFACE:
		// See staticassign's OCONVIFACE case for comments.
		n := n.(*ir.ConvExpr)
		val := ir.Node(n)
		for val.Op() == ir.OCONVIFACE {
			val = val.(*ir.ConvExpr).X
		}
		if val.Type().IsInterface() {
			return val.Op() == ir.ONIL
		}
		if types.IsDirectIface(val.Type()) && val.Op() == ir.ONIL {
			return true
		}

	// These implement IsNil.
	// Wrap in extra struct to hide interface type.
	doNil := []any{
		struct{ x *int }{},
		struct{ x any }{},
		struct{ x map[string]int }{},
		struct{ x func() bool }{},
		struct{ x chan int }{},
		struct{ x []string }{},
		struct{ x unsafe.Pointer }{},
	}
	for _, ts := range doNil {
		ty := TField(TypeOf(ts), 0)
		v := Zero(ty)
		v.IsNil() // panics if not okay to call

		ir.Dump("walk", n)
		base.Fatalf("walkExpr: switch 1 unknown op %+v", n.Op())
		panic("unreachable")

	case ir.OGETG, ir.OGETCALLERPC, ir.OGETCALLERSP:
		return n

	case ir.OTYPE, ir.ONAME, ir.OLITERAL, ir.ONIL, ir.OLINKSYMOFFSET:
		// TODO(mdempsky): Just return n; see discussion on CL 38655.
		// Perhaps refactor to use Node.mayBeShared for these instead.
		// If these return early, make sure to still call

		case ir.OMIN, ir.OMAX:
			// string or float requires runtime call, see (*ssagen.state).minmax method.
			return n.Type().IsString() || n.Type().IsFloat()

		case ir.OLITERAL, ir.ONIL, ir.ONAME, ir.OLINKSYMOFFSET, ir.OMETHEXPR,
			ir.OAND, ir.OANDNOT, ir.OLSH, ir.OOR, ir.ORSH, ir.OXOR, ir.OCOMPLEX, ir.OMAKEFACE,
			ir.OADDR, ir.OBITNOT, ir.ONOT, ir.OPLUS,
			ir.OCAP, ir.OIMAG, ir.OLEN, ir.OREAL,