On 2/21/10, Steven Bosscher <stevenb....@gmail.com> wrote: > It is interesting how this conflicts with your signature: > > "You can't buy a computer these days with less that a gigabyte." > > -- A.S.Tanenbaum, trying to defend Minix's fixed-size kernel arrays > > at FOSDEM 2010 > I take it you disagree with this? Because most people do not expect to > need 1GB for a Minix installation. ;-) It's a straw man, another example of bogus reasoning. Of course you can buy new computers with 64MB, and they are particularly suitable for simple kernels. The embedded Linux/BSD crowd at the presentation didn't seem very impressed either.
> You want to cater for a minority with old hardware. I > actually expect you'll find that those users are less naive than the > average gcc user. I want to cater for everyone, especially youngsters, learners and the poor struggling with whatever they can get their hands on. It's not even a rich country/poor country thing: I live in a run down industrial area of England where the local kids are gagging for anything that works. > Can you name these distributions? I can only name Debian > (http://lists.debian.org/debian-arm/2006/06/msg00015.html) A quick search for "unbreak-armv4t.patch" shows, at a glance on the first ten hits, fedora, openembedded, slind, openmoko, mamona, android-porting. I'll leave you to peruse page two on :) > Ubuntu also requires i686 or later. Ubuntu also needs 384MB to work these days, so it is a reasonable application-specific choice for that distro. GCC should not be tailored to high-end desktop, laptop and server machines. > But anyway, bringing ARM into this discussion is neither here nor there. It is a specific example of a pointlessly higher cpu default (for "arm-*") where such a decision was made in GCC and the annoyances it causes. which is what this thread had drifted into. > Your naive users (and mine) don't even know about -mcpu and -march. Exactly, so they go "cc hello.c; a.out" and get "Illegal instruction" unless they have a relatively new first-world PC. > >, which doesn't require them to recompile the compiler > Neither does compiling for i386/i486 or armv4 if you have a > cross-compiler for another default -- you can use -mcpu to "downgrade" > too. Of course. However it does bite cross-compilers because people end up distributing the C library compiled for a high-end CPU, so no program will run even when you do drop the -mcpu level. Raising it instead still works for everyone. > (**/me mumbles something incoherent about Pareto, etc...***) Moore's Law suggests that we should optimise most intensely for the physically slower processors, where sloth or speed translates into more real time, but I forgot that point in the last post :) Actually, this is irrelevant to the thread, since one always has to specify a CPU model in the tuple when configuring for i?86, and the thread was about an i686-* configuration tuple still producing a compiler that outputs i386 code by default, which does seem silly. Happy Sunday. M
