HP-UX/PA_RISC gcc-4.4.5 multiple libgomp failures, help please

["Peter O'Gorman" <pogma at thewrittenword dot com>]

Hi,

We built gcc-4.4.5 on all our systems, but on hppa2.0w-hp-hpux11.31 (a
32 bit build of gcc) we found that, though the compiler was able to
build perl-5.12.2, the resulting perl did not pass its tests.

So, we ran the gcc testsuite, and it passed nearly everything until it
came to libgomp:
Running /opt/build/gcc-4.4.5/libgomp/testsuite/libgomp.c/c.exp ...
FAIL: libgomp.c/copyin-1.c execution test
FAIL: libgomp.c/copyin-3.c execution test
FAIL: libgomp.c/nested-2.c execution test
FAIL: libgomp.c/pr24455.c execution test
FAIL: libgomp.c/pr29947-2.c execution test
FAIL: libgomp.c/pr42942.c execution test
Running /opt/build/gcc-4.4.5/libgomp/testsuite/libgomp.c++/c++.exp ...
Pid 23693 in trap loop, signal 11
[snip]
Pid 771 in trap loop, signal 11
FAIL: libgomp.c++/ctor-9.C  -O3 -fomit-frame-pointer -funroll-loops
execution test
FAIL: libgomp.c++/for-1.C  -O1  execution test
FAIL: libgomp.c++/for-1.C  -O2  execution test
FAIL: libgomp.c++/for-1.C  -O3 -fomit-frame-pointer  execution test
Pid 930 in trap loop, signal 11
FAIL: libgomp.c++/for-1.C  -O3 -fomit-frame-pointer -funroll-loops
execution test
[snip]
Pid 15005 in trap loop, signal 11
FAIL: libgomp.fortran/task1.f90  -O0  execution test
Pid 15641 in trap loop, signal 11
Test Run By pogma on Thu Dec  2 19:18:38 2010
Native configuration is hppa2.0-hp-hpux11.31
                === libgomp Summary ===

# of expected passes            2285
# of unexpected failures        173
# of unsupported tests          9

GCC 4.4.5 on hppa-hp-hpux11.23 built with the same options etc, reports:
                === libgomp Summary ===

# of expected passes            2458
# of unsupported tests          9

On hpux11.31, running the 11.23 built gcc etc. a lot of libgomp tests
fail again (the same gcc binaries that pass all their tests when run on
11.23).

Perl built with gcc-4.2.4 on hpux11.31 passes all its tests.

Perl built with gcc-4.4.5 and linked with -Wl,-B,immediate (similar
effect to setting LD_BIND_NOW at runtime) passes all its tests.
Similarly, export LDOPTS="-B immediate"; gmake check in libgomp passes
the tests.

Running individual tests does not fail, different tests fail on
different runs of the full libgomp testsuite (same with the perl
testsuite).

I would appreciate any hints etc. for where to look to find the
incompatibility between gcc-4.4 and hppa-hp-hpux11.31. I *think* it's
something to do with pthreads, but that's really just a guess, and I
don't know where to go from here.

Thanks,
Peter
-- 
Peter O'Gorman
pogma@thewrittenword.com