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Formerly div_var() had "fast path" short division code that was significantly faster when the divisor was just one base-NBASE digit, but otherwise used long division. This commit adds a new function div_var_int() that divides by an arbitrary 32-bit integer, using the fast short division algorithm, and updates both div_var() and div_var_fast() to use it for one and two digit divisors. In the case of div_var(), this is slightly faster in the one-digit case, because it avoids some digit array copying, and is much faster in the two-digit case where it replaces long division. For div_var_fast(), it is much faster in both cases because the main div_var_fast() algorithm is optimised for larger inputs. Additionally, optimise exp() and ln() by using div_var_int(), allowing a NumericVar to be replaced by an int in a couple of places, most notably in the Taylor series code. This produces a significant speedup of exp(), ln() and the numeric_big regression test. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCVwsBi-ND-t82Cuuh1=8ee6jdOpzsmGN+CUZB6yjLg9jw@mail.gmail.com
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.