On Mon, Jul 13, 2009 at 07:16:16PM -0300, Matt Turner wrote: > On Mon, Jul 13, 2009 at 6:17 PM, Aurelien Jarno<aurelien@xxxxxxxxxxx> wrote: > > On Mon, Jul 13, 2009 at 02:24:00PM -0400, Carlos O'Donell wrote: > >> On Mon, Jul 13, 2009 at 1:31 PM, Aurelien Jarno<aurelien@xxxxxxxxxxx> wrote: > >> > With a lot of patches (E)GLIBC 2.10 builds on alpha, but it fails on the > >> > testsuite for the memchr() function, which is an optimized assembly code > >> > on alpha. Unfortunately I don't speak alpha assembly very well, so help > >> > is needed. > >> > > >> > The problem is that the memchr() function on alpha uses prefetch, which > >> > can cause a page boundary to be crossed, while the standards (POSIX and > >> > C99) says it should stop when a match is found. > >> > > >> > I have built a small testcase (see file attached), which contains the > >> > code to trigger the bug and the assembly code of the memchr() function, > >> > copied from EGLIBC. > >> > > >> > It would be nice if someone can fix the assembly code so that the > >> > prefetching does not create memory faults. Thanks in advance. > >> > >> If you remove: > >> ./sysdeps/alpha/alphaev6/memchr.S > >> ./sysdeps/alpha/memchr.S > >> and allow the build to fallback on string/memchr.c do the tests pass? > >> > >> You can always add memchr.S routines back in a later release if you > >> need an immediate workaround. > > > > Yeah, it works, and that's actually my plan if I get no answer. But I > > would really like to see this fixed now, as otherwise, it will most > > probably stay like that indefinitely. > > > > -- > > Aurelien Jarno GPG: 1024D/F1BCDB73 > > aurelien@xxxxxxxxxxx http://www.aurel32.net > > > > I'm copying Richard Henderson and Ivan Kokshayshy on this, as they are > without a doubt the most knowledgeable people about this sort of > thing. Thanks. > As an aside, please make sure these two bugs are fixed in eglibc (I > don't know if they exist in eglibc, but I do realize that you filed > them against glibc yourself -- so this is just a reminder). > > http://sources.redhat.com/bugzilla/show_bug.cgi?id=5350 > http://sources.redhat.com/bugzilla/show_bug.cgi?id=5400 > I have already put a first set of patches needed for alpha in a git repository [1], and sent a pull request on the libc-ports mailing list. I hope it will work better than filling bug reports. If it also fails, I'll send them to EGLIBC. [1] http://git.aurel32.net/?p=glibc-ports.git;a=shortlog;h=refs/heads/alpha-for-upstream -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@xxxxxxxxxxx http://www.aurel32.net -- To unsubscribe from this list: send the line "unsubscribe linux-alpha" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
