[Bug c++/68476] New: microblaze: compilation of btSoftBody.cpp doesn't terminate with optimisation

[arnout at mind dot be]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68476

            Bug ID: 68476
           Summary: microblaze: compilation of btSoftBody.cpp doesn't
                    terminate with optimisation
           Product: gcc
           Version: 5.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: arnout at mind dot be
  Target Milestone: ---

In the buildroot automatic tests, we found that the compilation of one
particular file of the bullet package doesn't terminate. Note that this only
happens for the microblaze architecture.

To reproduce:
- configure gcc with --target=microblazeel-buildroot-linux-gnu
--disable-__cxa_atexit --with-gnu-ld --disable-libssp --disable-multilib
--disable-libquadmath --enable-tls --disable-libmudflap --enable-threads
--without-isl --without-cloog --disable-decimal-float --enable-shared
--disable-libgomp target_alias=microblazeel-buildroot-linux-gnu
--enable-languages=c,c++

- download bullet from https://github.com/bulletphysics/bullet3

- go to src/BulletSoftBody

- run microblazeel-buildroot-linux-gnu-g++ -DBulletSoftBody_EXPORTS
-DUSE_GRAPHICAL_BENCHMARK -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE
-D_FILE_OFFSET_BITS=64   -O1 -g -DNDEBUG -I..    -S btSoftBody.cpp

cc1plus will run indefinitely making no progress. If I run it with -da, the
last file produced is btSoftBody.cpp.192r.loop2_done


Note that it doesn't occur with -Os or no -O at all.


I don't work on bullet or microblaze, so it's difficult for me to provide more
information.