value %= divisor
			}
		case lex.LSH:
			p.next()
			shift := p.factor()
			if int64(shift) < 0 {
				p.errorf("negative left shift count")
			}
			return value << shift
		case lex.RSH:
			p.next()
			shift := p.term()
			if int64(shift) < 0 {
				p.errorf("negative right shift count")
			}
			if int64(value) < 0 {
				p.errorf("right shift of value with high bit set")
			}