[cfe-dev] mpfr 3.1.0 vs clang 3.0svn

[Jack Howarth]

Eric,
   I have opened radr://10291355, "Xcode 4.2 miscompiles tls support in MPFR 3.1.0", in radar.
The radar has an attached darwin11_clang_tls_bug.tar.bz2 test case which contains the libmpfr.4.dylib
and libfrtests.a libraries from MPFR built at -O0 as well as the preprocessed source for the
failing texceptions test case. The bad_build shell script demonstrates the miscompiled tls support
when texceptions.i is compiled by clang at -O2 and the good_build shell script demonstraties the
disappearance of the issue when texceptions.i is compiled by clang at -O0. This is as small a test
case that I can puzzle out.
   Hopefully the problem lies in clang and not the cctools from Xcode 4.2. If that is the case, I
can test any proposed fixes to clang svn (so that I can create additional test cases if tls-related
regressions in the MPFR testsuite remain).
             Jack