Compile time of Expression Templates in C++

[Richard Guenther]

On 10/10/06, Jochen Haerdtlein
<jochen.haerdtlein@informatik.uni-erlangen.de> wrote:
> Hello,
>
>     I am a PhD student working on the extended use of
> expression templates for solving partial differential equations.
> Thus, I did a lot of studying of expression templates papers,
> articles and expression templates implementations. Actually,
> I had some ideas for improving them for high performance
> platforms.
>
>    Since compile time of huge expression template programs is
> a severe problem, I am interested in the mechanisms within g++
> that are necessary to resolve the nested template constructs.
> Unfortunately, it is pretty hard (for me) to find any hints on that. Is
> there any documentation concerning the policies within gcc how
> the templates are resolved, instatiated, etc. ?
> Where is the time spent during compiling? I already started
> the -ftime-report option and got some information. Concerning that,
> about one third of the time is needed by the parser. But I would like
> to understand it in more detail, if possible.
>
>     First I would be happy for any reaction of you, just telling me
> whether my interests are complete nonsense or unsolvable.
> Maybe,  you can give me some hints, where I can find some
> answers, or somebody I can annoy.

You may want to look at PR29433.

Richard.