[Bug regression/53442] New: llvm 2.9 tblgen executable possibly miscompiled with gcc 4.7.0

["ncahill_alt at yahoo dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53442

             Bug #: 53442
           Summary: llvm 2.9 tblgen executable possibly miscompiled with
                    gcc 4.7.0
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: regression
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ncahill_alt@yahoo.com


This is a most complex problem, but an executable fails with gcc 4.7.0, giving
a segmentation fault.  But when linked with gcc 4.5.3, it works.  I say linked
because the same object files are involved, only the version of gcc for linking
changes.

It does appear the problem is with the executable itself, but it is so complex
that I am unable to generate a test case.  My suggestion to anyone trying to
reproduce this is to get a source release of llvm-2.9 for 32-bit x86, and if it
builds successfully, problem solved.  I give the configure command for the
package below.  This is not a bug yet, but a reported, possible bug occurrence,
and it may be that it happens elsewhere.  

In case this turns out to be something, I wanted it to be noted for now.

It occurs with the Release/bin/tblgen executable, which is generated in the
build process, and the error occurs after this line of output: Building
Intrinsics.gen.tmp from Intrinsics.td.

Thank you.
Neil.



The package was configured the package as follows:

configure --prefix=/usr --build=i686-pc-linux-gnu --host=i686-pc-linux-gnu
--mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share
--sysconfdir=/etc --localstatedir=/var/lib --enable-shared
--with-optimize-option= --enable-optimized --disable-assertions
--disable-expensive-checks --enable-targets=host-only
--with-llvmgccdir=/dev/null --with-llvmgcc=nope --with-llvmgxx=nope
--enable-bindings=none --enable-libffi


gcc -v...

Using built-in specs.
COLLECT_GCC=/usr/i686-pc-linux-gnu/gcc-bin/4.7.0/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i686-pc-linux-gnu/4.7.0/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: ../gcc-4.7.0/configure --disable-bootstrap --disable-libada
--disable-ld --disable-gold --enable-lto --enable-libssp
--enable-cloog-backend=isl --without-cloog --prefix=/usr
--bindir=/usr/i686-pc-linux-gnu/gcc-bin/4.7.0
--includedir=/usr/lib/gcc/i686-pc-linux-gnu/4.7.0/include
--datadir=/usr/share/gcc-data/i686-pc-linux-gnu/4.7.0
--mandir=/usr/share/gcc-data/i686-pc-linux-gnu/4.7.0/man
--infodir=/usr/share/gcc-data/i686-pc-linux-gnu/4.7.0/info
--with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/4.7.0/include/g++-v4
--host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --disable-altivec
--disable-fixed-point --without-ppl --enable-nls --without-included-gettext
--with-system-zlib --disable-werror --enable-secureplt --disable-multilib
--enable-libmudflap --disable-libgomp
--with-python-dir=/share/gcc-data/i686-pc-linux-gnu/4.7.0/python
--enable-checking=release --disable-libgcj --enable-languages=c,c++,fortran,lto
--enable-shared --enable-threads=posix --enable-__cxa_atexit
--enable-clocale=gnu --with-bugurl=http://bugs.gentoo.org/
Thread model: posix
gcc version 4.7.0 (GCC)