Messages in this thread | | | Date | Sat, 9 May 2009 05:13:08 -0400 | From | Theodore Tso <> | Subject | Re: Linux and LLVM |
| |
On Fri, May 08, 2009 at 09:50:04PM +0200, Grozdan wrote: > 2009/5/8 Jeff Garzik <jeff@garzik.org>: > > Grozdan wrote: > >> > > It is highly unlikely we will switch compilers away from gcc -- we have > > enough problems just supporting multiple gcc versions. > > > > That said, you could join the effort to get LLVM to compile under the > > kernel. Here is a meta-bug for that: > > http://llvm.org/bugs/show_bug.cgi?id=4068 > > > > It is a moot question until LLVM can actually build a bootable kernel :) > > Thanks for the quick answer! I was not aware that currently there's > lots of work until CLANG can compile a bootable Linux kernel. Thanks > for the link too. I'll dig through it
Note also that the list of architectures currently supported by Linux:
http://en.wikipedia.org/wiki/Linux_kernel_portability_and_supported_architectures
Seems to be a superset of the architectures supported by LLVM, and the CLANG web page states that it is production quality only on the x86 and x86_64 architectures. So "switch away from" seems to be a rather ambitious goal.
As Jeff has suggested, getting CLANG to at least be able to compile a single Linux kernel, on one architecture is clearly the first step.
The next step will be to work on fixing regressions on a wide variety of different kernel configurations such that in people's mind, that when a kernel bug is submitted, the probability that it is a compiler bug must be roughly the same as in GCC --- in other words, that for any give bug report submitted, P(LLVM/CLANG compiler bug) must be less than P(GCC compiler bug). At that point, assuming there is a large enough community of users who prefer to use LLVM/CLANG (presumably because its code generator is proving itself superior to gcc), it would be possible to call LLVM/CLANG "supported" under Linux.
I suspect we have quite a ways to go before we get to that point, and even then there is the issue of the architectures which aren't yet supported by LLVM.
Regards,
- Ted -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |