On 09/21/2017 09:41 PM, Andres Freund wrote: > On 2017-09-21 09:30:31 -0400, Tom Lane wrote: >> Andrew Dunstan <andrew.duns...@2ndquadrant.com> writes: >>> The speed of memset is hardly going to be the dominating factor in a >>> 'CREATE DATABASE' command, so we could certainly afford to change to >>> plain memset calls here. >> Another thought is that it may be time for our decennial debate about >> whether MemSet is worth the electrons it's printed on. I continue to >> think that any modern compiler+libc ought to do an equivalent or better >> optimization given just a plain memset(). If that seems to be true >> for recent MSVC, we could consider putting an #if into c.h to define >> MemSet as just memset for MSVC. Maybe later that could be extended >> to other compilers. > +many. glibc's memset is nearly an order of magnitude faster than MemSet > on my machine for medium+ length copies, and still 3-4 four times ~100 > bytes. And both gcc and clang optimize way the memcpy entirely when the > length is a fixed short length.
Perhaps we need some sort of small benchmark program that we can run on a representative set of platforms? I presume if you can make that assertion you already have something along those lines? cheers andrew -- Andrew Dunstan https://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers