Messages in this thread | | | Subject | Re: what libc+compiler is in use for development? | Date | Sun, 18 Jul 1999 17:59:27 -0400 | From | Horst von Brand <> |
| |
Steve Dodd <dirk@loth.demon.co.uk> said: > On Sun, Jul 18, 1999 at 01:15:49PM -0400, Horst von Brand wrote:
[...]
> > gcc-2.95 is around the corner, its prereleases generate _much_ better code > > than gcc-2.7.2.
> I was under the impression that Linus has disputed the code generation thing,
What Linus has been questioning (AFAIU him :) is that he knows exactly (more or less) what code gcc-2.7.2 will generate, and this isn't true with later versions. You'd have to understand that Linus is a efficiency freak, he wants minute control over the object code. The changed code generation algorithms, new and rewamped optimizations, and assorted other changes in the compiler mean that the certain way of writing code that used to give the fastest object doesn't necessarily do so so anymore. I'd also say that the linux kernel is _the_ piece of code that most uses (and stresses) the different extensions (and quirks, even bugs) of the gcc compiler. So the push towards more standards conformance, even the elimination of bugs in the compiler got at odds with Linus. A famous case was the bug in ia32 that allowed to write illegal asm statements (sadly in a way that was quite logical). Linus does have a point, but the egcs people have to care not just for the linux-kernel-compiler, they have to care for a general purpose tool, even a host of other languages (The current GCC (GNU Compiler Collection) includes C, C++, Objective C, FORTRAN 77, Java, and chill. More are to come, at least Pascal is supposed to be integrated soon AFAIK). I'd say that you loose somewhat locally, but the overall quality of the code is much better. And the egcs folks _do_ care for the kernel, a bug in the compiler exposed by the kernel is high priority; also caveats and workarounds for problems compiling the kernel are routinely posted in the compiler FAQ. -- Horst von Brand vonbrand@sleipnir.valparaiso.cl Casilla 9G, Viña del Mar, Chile +56 32 672616
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |