Re: [HACKERS] Windows warnings from VS 2017

On 2017-09-21 09:30:31 -0400, Tom Lane wrote:
> Andrew Dunstan <andrew.dunstan@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.

Greetings,

Andres Freund


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