On Fri, Jan 14, 2011 at 7:52 AM, Peter Blok <peter.b...@bsd4all.org> wrote: > Hi Ryan, > > Well I think gcc should not generate movdqa if it cannot guarantee the area > it is working on is aligned. If the stack is not aligned, it should generate > – probably less efficient – code that works.
Well that's the trouble, in Linux at least it *can* guarantee that the area is aligned. And it seems that according to kib, FreeBSD also intended to guarantee that alignment, but due to a bug always produced an unaligned stack(which explains why the hack I tried to fix the alignment didn't work -- the bug happened after we got to userland). > What is this area, if it is not a local variable allocated somewhere? Is it > some sort of stack probing? Is alloca used? Are variable length arrays used? To be honest I'm really not sure. It was dying somewhere in the constructor of a C++ class. Unfortunately due to a lot of inlining and gdb being a total piece of garbage, I wasn't able to suss out exactly what C++ code the instruction corresponded to, and once I understood the problem with movdqa I stopped digging in the C++ code. _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
