[llvm-bugs] [Bug 30292] New: infinite loop (?) in -simplifycfg

via llvm-bugs llvm-bugs at lists.llvm.org
Tue Sep 6 07:34:59 PDT 2016


            Bug ID: 30292
           Summary: infinite loop (?) in -simplifycfg
           Product: new-bugs
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: new bugs
          Assignee: unassignedbugs at nondot.org
          Reporter: willdtz at gmail.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

Created attachment 17215
  --> https://llvm.org/bugs/attachment.cgi?id=17215&action=edit
bitcode demonstrating bug, from libevent

Encountered this starting about a week ago on trunk, occurred when building

With the attached bc file:

$ opt event.bc -simplifycfg -disable-output -debug-pass=Executions
[2016-09-06 09:38:06.956737000] 0x3838f10     Executing Pass 'Simplify the CFG'
on Function 'event_base_loop'...

And it proceeds to never complete this pass (hours+).

I'm not sure what the best way to reduce a timing-related bug is, apologies for
the non-reduced test-case.  Even getting this bitcode was more trouble than I
expected (tips welcome, is there a better way?): I ended up using
-print-before=simplifycfg and kludging the function printing pass to dump the
entire module instead.

LMK if you have any questions or problems reproducing on trunk, thanks!

You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20160906/d335983b/attachment.html>

More information about the llvm-bugs mailing list