D on next-gen consoles and for game development

[Dmitry Olshansky]

24-May-2013 18:35, Manu пишет:
> On 24 May 2013 19:40, Dmitry Olshansky <dmitry.olsh at gmail.com
> <mailto:dmitry.olsh at gmail.com>> wrote:
>
>     24-May-2013 09:02, Manu пишет:
>
>         On 24 May 2013 14:11, Marco Leise <Marco.Leise at gmx.de
>         <mailto:Marco.Leise at gmx.de>
>         <mailto:Marco.Leise at gmx.de <mailto:Marco.Leise at gmx.de>>> wrote:
>
>              Am Thu, 23 May 2013 20:21:47 -0400
>              schrieb "Jonathan M Davis" <jmdavisProg at gmx.com
>         <mailto:jmdavisProg at gmx.com>
>              <mailto:jmdavisProg at gmx.com <mailto:jmdavisProg at gmx.com>>>:
>
>
>               > At some point, we're probably going to need to
>               > benchmark stuff more agressively and optimize Phobos in
>         general
>              more, because
>               > it's the standard library. And eliminating unnecessary
>         memory
>              allocations
>               > definitely goes along with that.
>               >
>               > - Jonathan M Davis
>
>              On a related note, a while back I benchmarked the naive Phobos
>              approach to create a Windows API (wchar) string from a D
>              string with using alloca to convert the string on a piece of
>              stack memory like this: http://dpaste.1azy.net/__b60d37d4
>         <http://dpaste.1azy.net/b60d37d4>
>              IIRC it was 13(!) times faster for ~100 chars of English text
>              and 5 times for some multi-byte characters.
>              I think this approach is too hackish for Phobos, but it
>              demonstrates that there is much room.
>
>
>         I don't think it's hack-ish at all, that's precisely what the
>         stack is
>         there for. It would be awesome for people to use alloca in
>         places that
>         it makes sense.
>         Especially in cases where the function is a leaf or leaf-stem
>         (ie, if
>         there is no possibility of recursion), then using the stack
>         should be
>         encouraged.
>         For safety, obviously phobos should do something like:
>             void[] buffer = bytes < reasonable_anticipated_buffer___size ?
>         alloca(bytes) : new void[bytes];
>
>         toStringz is a very common source of allocations. This alloca
>         approach
>         would be great in those cases, filenames in particular.
>
>
>     Alternatively just make a TLS buffer as scratchpad and use that
>     everywhere.
>
>
> How is that any different than just using the stack in practise?

Can pass across function boundaries up/down. Can grow arbitrary large 
without blowing up.

-- 
Dmitry Olshansky