On Sun, Jun 21, 2009 at 4:21 PM, John David Anglin<dave@xxxxxxxxxxxxxxxxxx> wrote: >> Sorry, this turns out not to be correct, after tracing the assembly >> completely (including loads in delayed branches) it looks like the >> location read from the pid through ptrace might be wrong. I'll have to >> keep debugging this. > > Delayed branches are a nasty invention. I am testing a patch to > fix a problem that appeared last week. Interesting. > When a conditional branch with an unfilled delay slot is followed > by an asm, bad things may end up in the delay slot. Even worse, > the branch may branch into the delay slot. GCC has no idea what's > in an asm. So, I'm trying to add a nop in the delay slot when a > conditional branch is followed by an asm. There is an on-and-off-again bug in glibc's vfprintf.c implementation that causes DBR to miscompile that file, but it comes and goes depending on the gcc version. I filed a bug once, but because I couldn't produce a reduced testcase Pinski closed it. If I see it again I'll try again to produce a reduced testcase. How's 4.4 on hppa? Cheers, Carlos. -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
