So regarding my assumptions about translating the D front end expressions to GCC? Is that all simpler than I imagine? Do you think GDC generates optimal code comparable to C code?
What about pure functions, can you make good on optimisations like caching results of pure functions, moving them outside loops, etc? On 6 January 2012 00:03, Iain Buclaw <ibuc...@ubuntu.com> wrote: > On 5 January 2012 16:49, Manu <turkey...@gmail.com> wrote: > >> D is not a compiler, it is a language. Furthermore it is not true that > >> DMDs backend is rubbish and there are already more backends than just > the > >> DMC backend. > > > > > > Sorry, I was generalising a little general in that claim. And where I say > > 'rubbish', I was drawing comparison to the maturity of C compilers for > x86, > > which STILL have trouble and make lots of mistakes with centuries of man > > hours of work. > > DMD has inferior code gen (there was a post last night comparing some > > disassemblies of trivial programs with GDC), will probably never rival > GCC, > > that's fine, it's a reference, I get that. > > But to say that using GDC will magically fix code gen is also false. I'm > not > > familiar with the GCC code, so I may be wrong, but my understanding is > that > > there is frontend work, and frontend-GCC glue work that will allow for > back > > end optimisation (which GCC can do quite well) to work properly. This is > > still a lot of work for a small OSS team. > > I also wonder if the D language provides some opportunities for > optimisation > > that aren't expressible in other languages, and therefore may not already > > have an expression in the GCC back end... so I can imagine some of future > > optimisations frequently discussed in this forum won't just magically > appear > > with GCC/LLVM maturity. I can't imagine Iain and co extending the GCC > back > > end to support some obscure D optimisations happening any time soon. > > > > Actually, it's just me. ;) > > So far I have come across no D optimisations that aren't supported in > GCC. Infact, most of the time I find myself thinking of how I can use > obscure GCC optimisation X to improve D. One example is an > interesting feature of Fortran, though written with C++ in mind. Seems > like something that could be right up D's street. > > > http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D&article_id=147822 > > -- > Iain Buclaw > > *(p < e ? p++ : p) = (c & 0x0f) + '0'; >
