e848c3799cUpdate sage files for new formulae (Peter Dettman)d64bb5d4f3Add fe_half tests for worst-case inputs (Peter Dettman)4eb8b932ffFurther improve doubling formula using fe_half (Peter Dettman)557b31fac3Doubling formula using fe_half (Pieter Wuille)2cbb4b1a42Run more iterations of run_field_misc (Pieter Wuille)9cc5c257edAdd test for secp256k1_fe_half (Pieter Wuille)925f78d55eAdd _fe_half and use in _gej_add_ge (Peter Dettman) Pull request description: - Trades 1 _half for 3 _mul_int and 2 _normalize_weak Gives around 2-3% faster signing and ECDH, depending on compiler/platform. ACKs for top commit: sipa: utACKe848c3799cjonasnick: ACKe848c3799creal-or-random: ACKe848c3799cTree-SHA512: 81a6c93b3d983f1b48ec8e8b6f262ba914215045a95415147f41ee6e85296aa4d0cbbad9f370cdf475571447baad861d2cc8e0b04a71202d48959cb8a098f584