[Tinycc-devel] RE :Re: modern c++ compiler written in C (food forthought)

[Christian JULLIEN]

Hum, sorry I still don't understand quite well your exact motivation with Cfront.

motivation-1) POC to make Cfront usable with TCC toolchain.
- A funny toy project. Change Cfront so that it compiles with TCC *and possibliy* change CFront C code generator so that unmodified TCC can compile and run Cfront valid programs (nowhere here I use C++ term or I speak about speed)

motivation-2) produce the world fastest CFront compiler ever.
 - change Cfront so that it compiles with gcc -O3  *and possibliy* change 
CFront C code generator so that unmodified TCC can compile and run 
Cfront valid programs (nowhere here I use C++ term). For sure, this is the fastest way to produce Cfront programs that execute something.

motivation-3) have an object oriented C extension on top of TCC
- Cfront is an object oriented C extension which allows a kind of OOP programming (sometimes very close to ISO C++). Btw why do you need this as, due to license limitation, you will not be able to ship anything unless you limit yourself to the common subset of both 'modern c++' and Cfront, even stream ios are different.

motivation-4) have a modern c++ compiler written in C.
- Cfront is definitely not a modern c++, it will take age to make it c++ compliant, even with C++98

other motivation?

Christian
> ----- message d'origine -----
> De : "Jared Maddox" <address@hidden>
> date mar. 03/11/2015 00:03 (GMT +01:00)
> À : "address@hidden" <address@hidden>
> Objet : Re: [Tinycc-devel] modern c++ compiler written in C (food forthought)
>
> > Date: Sun, 1 Nov 2015 07:30:14 +0100
> > From: "Christian Jullien" <address@hidden>
> > To: <address@hidden>
> > Subject: Re: [Tinycc-devel] modern c++ compiler written in C (food      for
> >         thought)
> > Message-ID: <address@hidden>
> > Content-Type: text/plain;       charset="us-ascii"
> >
> >> : in fact, Comeau C/C++ compiles to C, and until recently was the ONLY
> > major compiler to support some C++ features.
> >
> > Sure, C backend as interim code generator works well provided you rely on C
> > optimizer to polish the code. I do the same with my OpenLisp compiler (see
> > how it works here https://en.wikipedia.org/wiki/OpenLisp#Compiler).
> > The idea is to first optimize as much as you can and then target a so simple
> > C code that it's a piece of cake for C optimizer to finish the job.
> > My compiler beats native "Lisp->bare metal assembler" compilers because it
> > uses all tricks -O3 is able to do. It achieves good performances at the
> > price of a very long optimization analysis (sometimes, a single lisp file
> > generates half megabyte non commented C file!!).
> >
> > NOW
> >
> > What is "funny" with tinycc is that, due to the lack of optimization,
> > compiled code is twice as SLOW as interpreted code and remember that my lisp
> > compiler already does branch tension, dead code elimination, constant
> > folding, redundant store elimination and few other optimization before C
> > code generation.
> >
> > I bet it would be even worse with the code Cfront generates.
> >
>
> If you read my previous email, you'll see that at no point did I say
> that low speed of resulting programs should be considered a reason for
> this project to stop. This is because low speed of resulting programs
> should not be considered a reason for this project to stop. TCC has
> never been about producing fast programs, but instead has always been
> about producing those programs quickly. The only relevant question is
> whether it can compile programs quicker than the common C++ compilers,
> everything else is a distraction.
>
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