On Thu, Mar 15, 2007 at 05:30:48PM -0700, Mark Mitchell wrote: > Joe Buck wrote: > > >> For what it's worth, I bootstrapped on a few different GNU/Linux > >> systems with different kernels and base compilers. I only saw > >> bootstrap comparison failures on one; that one was running Red Hat 9 > >> and had gcc 3.2.2 installed in /usr/bin. On that one, a bootstrap4 > >> worked. So I assumed that that one was due to some miscompilation of > >> stage1. > > > > Yes, this has been reported before (I've also seen bootstrap failures > > when using Red Hat's version 3.2.3 on an x86 RHEL3 box). > > I do indeed generally build GCC releases on an RHEL3 box. However, I > believe that I was using a version of GCC 3.4.x (built by CodeSourcery) > as the bootstrap compiler. It does seem like a suspiciously similar > situation, though; I'm sure that Joseph will be able to tell us if the > problem is reproducible with GCC 3.4.x.
The problem does not happen with 3.4.x at least for x==2. I regularly use gcc 3.4.2 as the bootstrap compiler for my gcc testing. Here's last night's run for the 4.2 branch: http://gcc.gnu.org/ml/gcc-testresults/2007-03/msg00710.html At one point I considered trying a search to see which files get miscompiled, by combining stage1 object files from a run with 3.2.3 and 3.4.2 and trying to do the rest of the bootstrap with that, then varying which .o files come from which compilers. But then I got much busier and lost the motivation.
