2007-01-08 Richard Guenther <rguenther@suse.de>

2007-01-08  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/23603
        * tree-vrp.c (set_value_range_to_truthvalue): New function.
        (extract_range_from_binary): Fall back to truthvalue instead of
        varying for TRUTH_*_EXPR.
        (extract_range_from_comparison): Fall back to truthvalue instead of
        varying.
        (vrp_visit_phi_node): Don't adjust new range bounds to +INF/-INF
        if all visited PHI values were constant.

        * gcc.dg/tree-ssa/vrp31.c: New testcase.
        * gcc.dg/tree-ssa/vrp32.c: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120578 138bc75d-0d04-0410-961f-82ee72b054a4