[Bug rtl-optimization/33796] valgrind error with -O2 for linux kernel code

["bergner at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from bergner at gcc dot gnu dot org  2007-10-17 14:21 -------
People using valgrind already have to deal with false positives and actual 
uninitialized uses (like this one) that are harmless.  If you look at your
valgrind install, you'll see that there are several error suppression files
installed with valgrind:

  bergner@begna:~/gcc/bugs> rpm -ql valgrind | grep '.supp$'
  /usr/lib64/valgrind/default.supp
  /usr/lib64/valgrind/glibc-2.2.supp
  /usr/lib64/valgrind/glibc-2.3.supp
  /usr/lib64/valgrind/glibc-2.4.supp
  /usr/lib64/valgrind/glibc-2.5.supp
  /usr/lib64/valgrind/xfree-3.supp
  /usr/lib64/valgrind/xfree-4.supp

To suppress this particular error/warning, you just need to create another
suppression file for this error with the contents below and pass
--suppressions=/path/to/sparseset.supp to valgrind and all should be well.

bergner@begna:~/gcc/bugs> cat sparseset.supp 

{
   SparseSet-Cond-0
   Memcheck:Cond
   fun:global_conflicts
   fun:rest_of_handle_global_alloc
   fun:execute_one_pass
   fun:execute_pass_list
   fun:execute_pass_list
   fun:tree_rest_of_compilation
   fun:cgraph_expand_function
   fun:cgraph_optimize
   fun:c_write_global_declarations
   fun:toplev_main
   fun:main
}

{
   SparseSet-Value4-0
   Memcheck:Value4
   fun:global_conflicts
   fun:rest_of_handle_global_alloc
   fun:execute_one_pass
   fun:execute_pass_list
   fun:execute_pass_list
   fun:tree_rest_of_compilation
   fun:cgraph_expand_function
   fun:cgraph_optimize
   fun:c_write_global_declarations
   fun:toplev_main
   fun:main
}


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33796