Created attachment 28512
gdb backtrace

Root cause:

PRE bases on the result of value numbering (run_scc_vn). At the end, it
free_scc_vn. But before free_scc_vn, it might call cleanup_tree_cfg ();

  if (do_eh_cleanup || do_ab_cleanup)
    cleanup_tree_cfg ();

cleanup_tree_cfg might call make_ssa_name which might reuse some "name"
from the FREE_SSANAMES list. If the VN_INFO of the "name" is NULL,
free_scc_vn will "Segmentation fault".

Richard's patch makes "do_eh_cleanup" to false. So cleanup_tree_cfg is
not called in PRE. Then no new ssa name will be created.

bt.log shows the gdb backtrace to create a new ssa name.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1065559

Title:
  [regression] cone ftbfs on armel/armhf using GCC 4.7

To manage notifications about this bug go to:
https://bugs.launchpad.net/gcc/+bug/1065559/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to