[Bug libgomp/42829] New: TLS detection in ./configure is wrong.

["jos dot de_laender at telenet dot be" <gcc-bugzilla at gcc dot gnu dot org>]

In attachment, you find the code that is used inside the configure m4 macro for
detecting the presence of TLS.

This check is unreliable.

When compiled with -O2 (as done in configure) the result might be that the
compiler reports same adress due to optimization and decides there is no TLS.

When compiled with -O0, it yields the correct result.

This is an optimization artefact. Please extend the test with the two lines I
put in comment. This way the test succeeds correctly, even after optimization.


-- 
           Summary: TLS detection in ./configure is wrong.
           Product: gcc
           Version: 4.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jos dot de_laender at telenet dot be
  GCC host triplet: i686-pc-mingw32
GCC target triplet: mingw64 - see description.


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42829