Table schema:
CREATE TABLE table_name_98 (sign INTEGER, total_bits VARCHAR, bits_precision VARCHAR, type VARCHAR)

Question: What's the sum of sign with more than 53 bits precision, double extended (80-bit) type, and more than 80 total bits?
SQL: SELECT SUM(sign) FROM table_name_98 WHERE bits_precision > 53 AND type = "double extended (80-bit)" AND total_bits > 80