[Bug middle-end/66276] [5/6 Regression] internal compiler error: in get_loop_body, at cfgloop.c:856

[martin.sjolund at liu dot se]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66276

--- Comment #6 from Martin Sjölund  ---
Thank you. I can confirm our compiler again bootstraps using gcc 5 branch using
-O2. Sadly, -O2 gives different behaviour than -O1, so I will need to
investigate and possibly file another bug report.

[Bug middle-end/66276] New: [5 regression] internal compiler error: in get_loop_body, at cfgloop.c:856

[martin.sjolund at liu dot se]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66276

Bug ID: 66276
   Summary: [5 regression] internal compiler error: in
get_loop_body, at cfgloop.c:856
   Product: gcc
   Version: 5.1.0
   URL: https://github.com/OpenModelica/OMCompiler
Status: UNCONFIRMED
  Severity: critical
  Priority: P3
 Component: middle-end
  Assignee: unassigned at gcc dot gnu.org
  Reporter: martin.sjolund at liu dot se
CC: martin.sjolund at liu dot se
  Target Milestone: ---
  Host: x86_64-unknown-linux-gnu
Target: x86_64-unknown-linux-gnu
 Build: x86_64-unknown-linux-gnu

Created attachment 35618
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35618&action=edit
File triggering the bug (pre-processed and slightly trimmed down from the
original)

Configured with: ./configure --prefix=/opt/gcc-5.1.0
gcc version 5.1.0 (GCC) 

$ /opt/gcc-5.1.0/bin/gcc -O2 Matching.c
Matching.c: In function ‘omc_Matching_PR__FIFO__FAIRrelabel’:
Matching.c:3319:1: internal compiler error: in get_loop_body, at cfgloop.c:856
 }
 ^
0x6ba046 get_loop_body(loop const*)
../.././gcc/cfgloop.c:856
0x9358b0 predict_loops
../.././gcc/predict.c:1580
0x9358b0 tree_estimate_probability()
../.././gcc/predict.c:2371
0x936542 execute
../.././gcc/predict.c:3066

The original code compiles fine in gcc 4.4-4.9 and clang. It crashes in 5.1.0,
the svn 5 branch and svn trunk.

Does not seem to be related to
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65517