[Bug c/87242] optimize -O2 incorrect output

[rpluim at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87242

rpluim at gmail dot com changed:

           What    |Removed                     |Added
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                 CC|                            |rpluim at gmail dot com

--- Comment #6 from rpluim at gmail dot com ---
Based on my bisection of gcc using the same emacs test case, this was fixed by:

    commit e98da821c1ee4450bbe40a0278cd75803706aa7c (HEAD, refs/bisect/new)
    Author: hubicka <address@hidden>
    Date:   Sun Dec 20 05:50:29 2015 +0000

                PR middle-end/65337
                * tree-ssa-dce.c (bb_postorder): New static var.
                (forward_edge_to_pdom): Remove.
                (remove_dead_stmt): Instead of redirecting edges only keep an 
edge
                on a path to nearest live BB.
                (eliminate_unnecessary_stmts): Free bb_postorder.
                * cfganal.c (dfs_find_deadend): Add START_POINTES.
                * cfganal.h (inverted_post_order_compute): Update prototype.


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