* toplev.h (flag_delete_null_pointer_checks): Move from here to...

        * flags.h (flag_delete_null_pointer_checks): Here.
        * tree-flow.h (cprop_into_successor_phis): Add argument to prototype.
        * tree-phinodes.c (resize_phi_node): Initialize PHI_ARG_NONZERO.
        (add_phi_arg, remove_phi_arg_num): Similarly.
        * tree-ssa-copy.c (cprop_into_successor_phis): Propagate nonzero
        property into PHI nodes.
        * tree-ssa-dom.c: Remove redundant inclusion of flags.h.
        (record_equivalences_from_phis): If all PHI arguments are known to be
        nonzero, then the result must be nonzero as well.
        (cprop_into_phis): Pass nonzero_vars bitmap to cprop_into_successor_phis        (record_equivalences_from_stmt): Check flag_delete_null_pointer_checks
        appropriately.  Walk the USE-DEF chains and propagate nonzero property
        as appropriate.
        * tree.h (PHI_ARG_NONZERO): Define.
        (phi_arg_d): Add nonzero flag.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@81968 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 4 insertions, 0 deletions

diff --git a/gcc/flags.h b/gcc/flags.h
index 8778b635392..6f8f5f67ea3 100644
--- a/gcc/flags.h
+++ b/gcc/flags.h
@@ -323,6 +323,10 @@ extern int flag_cse_skip_blocks;
    perform miscellaneous relatively-expensive optimizations.  */
 extern int flag_expensive_optimizations;
 
+/* Nonzero means to use global dataflow analysis to eliminate
+   useless null pointer tests.  */
+extern int flag_delete_null_pointer_checks;
+
 /* Nonzero means don't put addresses of constant functions in registers.
    Used for compiling the Unix kernel, where strange substitutions are
    done on the assembly output.  */