[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Re: [f-cpu] Winograd DCT on my seul.org account

>On Fri, Apr 19, 2002 at 09:09:49AM +0200, djrom wrote:
>> it cause the problem of gcc to (re)raise. optimisations for FC0 are very
>> different from usual optimisations, even for RISC processors. I don't
>> know the real structure of gcc, but I guess it'll be very difficult to
>> put FC0 tricks without breaking the portability, no ? I even wonder if
>> rewriting a new compiler won't be much easier than trying to add such
>> things in gcc, if we want the compiler to be good. we don't want to see
>> the F-Cpu ends like the PIV, used at less than 30%, right ?

>I guess that writing a new C compiler will indeed be easier than
>hacking gcc.

that's what I meant. 

>> moreover, we should perhaps think about another langage to be used
>> on modern processors. C is very limited in his expressivity, so the
>> operations like SIMD or "real" optimisations put a ton of work on the
>> compiler's shoulders. it shouldn't just try to optimise, but it must even
>> try to *understand* what the programmers meant. is there a langage really
>> usable for modern RISC processors ? maybe we should try to return to lisp
>> or ML, or something like that, no ? that's could also be a way to promote
>> new langages: I don't want 2030's processors to be always coded in C ! :-)

>And I don't want to be unable to code in C in 2030. I like lisp, but...
I haven't said, that we should stop to write C compilers ! :-) I was talking about the *main* langage. 

>C is very limited in its expressivity? Huh?

yes. you use a lots of tricks in C (casting, use of void *, "bare metal" objects with structures, intensive use of macros, ...) to hide the limited level of abstraction of the langage. look at a macro-assembler (like nasm), you'll see that C is very near of that, with just the portability advantage. I'm not saying, that C is at the same level than assembly langage, but it's clear, that C is too low-level for a modern computer, who's more complex than a old one, right ? so, as the complexity increase, you need a more abstracted langage, to avoid the necessity of very nasty tricks. if a langage needs these tricks, he's limited in its expressivity. C needs these tricks. 

>> if *we* don't promote new langages, we won't be able to count on Intel
>> to do it ! :-)

>Our goal is not to promote programming languages. Neither is it Intel's.
Our goal is to improve computer science isn't it ? :-)

 Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
 "All I wanna do is have a little fun before I die"
To unsubscribe, send an e-mail to majordomo@seul.org with
unsubscribe f-cpu       in the body. http://f-cpu.seul.org/
To unsubscribe, send an e-mail to majordomo@seul.org with
unsubscribe f-cpu       in the body. http://f-cpu.seul.org/