[Bug target/65171] New: [5 Regression] r214254 causes thousands of std::length_errors running boost testsuite on ppc64le

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65171

            Bug ID: 65171
           Summary: [5 Regression] r214254 causes thousands of
                    std::length_errors running boost testsuite on ppc64le
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: wschmidt at gcc dot gnu.org
              Host: powerpc64le-unknown-linux-gnu
            Target: powerpc64le-unknown-linux-gnu
             Build: powerpc64le-unknown-linux-gnu

Created attachment 34842
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34842&action=edit
unreduced testcase

Starting with r214254 thousands of std::length_errors are thrown
during a boost testsuite run on powerpc64le.
ppc64 big-endian is fine.

See: http://www.boost.org/development/tests/develop/developer/summary.html
trippels_power8_gcc-5.0_c++11 (big-endian) vs.
trippels_powerpc64le_gcc-5.0_c++11 (little-endian)

e.g.:

trippels@gcc2-power8 tools % g++ -w -ftemplate-depth-128 -O3 -finline-functions
-Wno-inline -Wall -fPIC -std=c++11 -mcpu=power8 -DBOOST_ALL_NO_LIB=1 -DNDEBUG
-I".." -I"../.." "../libs/sort/test/float_sort_test.cpp"
trippels@gcc2-power8 tools % ./a.out
Running 1 test case...
unknown location(0): fatal error: in "test_main_caller( argc, argv )":
std::length_error: basic_string::assign
../libs/sort/test/float_sort_test.cpp(68): last checkpoint

*** 1 failure detected in test module "Test Program"

Sorry, but reducing seems to be impossible.