Messages in this thread | | | Date | Sun, 15 Nov 1998 10:50:25 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: Linux-asm (was A patch for linux 2.1.127) |
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On Sun, 15 Nov 1998, Riccardo Facchetti wrote:
> On Sat, 14 Nov 1998, Richard B. Johnson wrote: [SNIPPED] > > I have read your paper, the C code and the Assembly code. > > No problems understanding C code but Assembly ... I have programmed in 16 > bit Intel Assembly long time ago (but I am not a real Assembly programmer) > and I am able to follow (sort of) the instruction paths. IMHO the real > problem is that Assembly need an Assembly programmer to be fully > understood and mantained while C is much more easy to mantain. Even more, > an Assembly programmer can mantain C code while a C programmer may not be > able to mantain asm code. We need a portable and mantainable kernel. Of > course I can imagine that for some well defined code paths (like fast > default cases) or counting functions (like checksumming) asm equivalents > can be the best solution, but there is a limit at this one too: > fast asm code for i386 != i486 != P5 != P6 so there should be something > like: > > #if defined(i386) > #include "fasti386.S" > #elif defined(i486) > #include "fasti486.S" > #elif defined(P5) > #include "fastP5.S" > #elif defined(P6) > #include "fastP6.S" > else > #include "slow.c" > #endif > This might be a bit extreme, but I get your point!
> and we need someone that is willing to mantain all the different > implementations in C and in asm and maybe write new ones for P7, P8 etc > etc. To add more complexity someone should provide Alpha assembly version > and MIPS and SPARC32 and SPARC64 and motorola etc etc. This is okay for > something like checksumming but IMHO it will be a real pain if someone > will come out rewriting e.g. filesystem code in Assembly. > In this case I say slow C code is better than superfast Assembly code. > > OTOH I've enjoyed your paper Assembly Language, good work :) > > Ciao, > Riccardo. > Thanks!
Cheers, Dick Johnson ***** FILE SYSTEM WAS MODIFIED ***** Penguin : Linux version 2.1.127 on an i586 machine (66.15 BogoMips). Warning : It's hard to remain at the trailing edge of technology.
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