[Bug lto/47532] New: valgrind errors while compiling with -flto

["Joost.VandeVondele at pci dot uzh.ch" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47532

           Summary: valgrind errors while compiling with -flto
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: Joost.VandeVondele@pci.uzh.ch


Created attachment 23162
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23162
testcase, compile under valgrind to see error

==5789== Conditional jump or move depends on uninitialised value(s)
==5789==    at 0xC5E14A: longest_match (deflate.c:1140)
==5789==    by 0xC5E6F1: deflate_slow (deflate.c:1595)
==5789==    by 0xC5F5F0: deflate (deflate.c:790)
==5789==    by 0xB931B1: lto_end_compression (lto-compress.c:195)
==5789==    by 0xB90F34: lto_end_section (lto-section-out.c:148)
==5789==    by 0xB9146E: lto_destroy_simple_output_block
(lto-section-out.c:512)
==5789==    by 0xB83FE9: output_cgraph (lto-cgraph.c:1008)
==5789==    by 0xB900B5: lto_output (lto-streamer-out.c:2252)
==5789==    by 0x7236E2: ipa_write_summaries_2 (passes.c:1648)
==5789==    by 0x723EE5: ipa_write_summaries (passes.c:1678)
==5789==    by 0x92E4A9: cgraph_optimize (cgraphunit.c:1797)
==5789==    by 0x92E5C9: cgraph_finalize_compilation_unit (cgraphunit.c:1083)

compile the attached testcase with 

valgrind --tool=memcheck --trace-children=yes gfortran -flto -c test.f90


-v details : 

sing built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc/configure
--prefix=/data03/vondele/gnu/gcc_trunk/install --enable-languages=c,c++,fortran
--disable-multilib --enable-plugins --enable-cloog-backend=isl
--with-ppl=/data03/vondele/gnu/ppl-0.11/install
--with-cloog=/data03/vondele/gnu/cloog-0.16.1/install/
--with-libelf=/data03/vondele/gnu/libelf-0.8.13/install --enable-gold
--enable-checking=release
Thread model: posix
gcc version 4.6.0 20110128 (experimental) [trunk revision 169358] (GCC) 
COLLECT_GCC_OPTIONS='-v' '-c' '-flto' '-mtune=generic' '-march=x86-64'

/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/f951
test.f90 -quiet -dumpbase test.f90 -mtune=generic -march=x86-64 -auxbase test
-version -flto -fintrinsic-modules-path
/data03/vondele/gnu/gcc_trunk/install/lib/gcc/x86_64-unknown-linux-gnu/4.6.0/finclude
-o /dev/shm/vondele/ccfZ59wz.s
GNU Fortran (GCC) version 4.6.0 20110128 (experimental) [trunk revision 169358]
(x86_64-unknown-linux-gnu)
        compiled by GNU C version 4.6.0 20110128 (experimental) [trunk revision
169358], GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU Fortran (GCC) version 4.6.0 20110128 (experimental) [trunk revision 169358]
(x86_64-unknown-linux-gnu)
        compiled by GNU C version 4.6.0 20110128 (experimental) [trunk revision
169358], GMP version 4.3.2, MPFR version 2.4.2, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
COLLECT_GCC_OPTIONS='-v' '-c' '-flto' '-mtune=generic' '-march=x86-64'
 as --64 -o test.o /dev/shm/vondele/ccfZ59wz.s
COMPILER_PATH=/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/:/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/:/data03/vondele/gnu/gcc_trunk/install/libexec/gcc/x86_64-unknown-linux-gnu/:/data03/vondele/gnu/gcc_trunk/install/lib/gcc/x86_64-unknown-linux-gnu/4.6.0/:/data03/vondele/gnu/gcc_trunk/install/lib/gcc/x86_64-unknown-linux-gnu/
LIBRARY_PATH=/data03/vondele/gnu/gcc_trunk/install/lib/gcc/x86_64-unknown-linux-gnu/4.6.0/:/data03/vondele/gnu/gcc_trunk/install/lib/gcc/x86_64-unknown-linux-gnu/4.6.0/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/data03/vondele/gnu/gcc_trunk/install/lib/gcc/x86_64-unknown-linux-gnu/4.6.0/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-c' '-flto' '-mtune=generic' '-march=x86-64'