Add functions to calculate the next power of 2 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 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/f0705bb6286d8a24e08ddd99641264ba947ebd03 Modified Files -------------- src/include/port/pg_bitutils.h | 72 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+)
