[Bug tree-optimization/60770] disappearing clobbers

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60770

--- Comment #10 from Marc Glisse <glisse at gcc dot gnu.org> ---
Author: glisse
Date: Mon Nov  3 10:47:04 2014
New Revision: 217034

URL: https://gcc.gnu.org/viewcvs?rev=217034&root=gcc&view=rev
Log:
2014-11-03  Marc Glisse  <marc.gli...@inria.fr>

    PR tree-optimization/60770
gcc/
    * tree-into-ssa.c (rewrite_update_stmt): Return whether the
    statement should be removed.
    (maybe_register_def): Likewise. Replace clobbers with default
    definitions.
    (rewrite_dom_walker::before_dom_children): Remove statement if
    rewrite_update_stmt says so.
    * tree-ssa-live.c: Include tree-ssa.h.
    (set_var_live_on_entry): Do not mark undefined variables as live.
    (verify_live_on_entry): Do not check undefined variables.
    * tree-ssa.h (ssa_undefined_value_p): New parameter for the case
    of partially undefined variables.
    * tree-ssa.c (ssa_undefined_value_p): Likewise.
    (execute_update_addresses_taken): Do not drop clobbers.

gcc/testsuite/
    * gcc.dg/tree-ssa/pr60770-1.c: New file.


Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr60770-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-into-ssa.c
    trunk/gcc/tree-ssa-live.c
    trunk/gcc/tree-ssa.c
    trunk/gcc/tree-ssa.h