f0705bb628
There are many areas in the code where we need to determine the next highest power of 2 of a given number. We tend to always do that in an ad-hoc way each time, generally with some tight for loop which performs a bitshift left once per loop and goes until it finds a number above the given number. Here we add two generic functions which make use of the existing pg_leftmost_one_pos* functions which, when available, will allow us to calculate the next power of 2 without any looping. Here we don't add any code which uses these new functions. That will be done in follow-up commits. Author: David Fetter, with some minor adjustments by me Reviewed-by: John Naylor, Jesse Zhang Discussion: https://postgr.es/m/20200114173553.GE32763%40fetter.org
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/.