n := n.(*ir.BinaryExpr)
		a := s.expr(n.X)
		b := s.expr(n.Y)
		bt := b.Type
		if bt.IsSigned() {
			cmp := s.newValue2(s.ssaOp(ir.OLE, bt), types.Types[types.TBOOL], s.zeroVal(bt), b)
			s.check(cmp, ir.Syms.Panicshift)
			bt = bt.ToUnsigned()
		}
		return s.newValue2(s.ssaShiftOp(n.Op(), n.Type(), bt), a.Type, a, b)
	case ir.OANDAND, ir.OOROR:
		// To implement OANDAND (and OOROR), we introduce a