[PATCH] Fix PR34263: Cleaning up latch blocks

[Revital1 Eres <ERES at il dot ibm dot com>]

Hello,

Following the RFC message
(http://gcc.gnu.org/ml/gcc/2007-12/msg00015.html), this patch tries
to clean up latch blocks in the out-of-ssa phase for the purpose of
restoring single-basic-block loops.  This can be helpful not only in the
SMS perspective. Given the fact we are in stage 3 I can alternatively
address this inside the SMS (and not in out-of-ssa).

The patch was successfully tested a week ago (when I posted the RFC
message) on ppc64 and I am re-checking it now to verify it is still OK.

OK for mainline once testing completes?

:ADDPATCH <tree-opt>:

Thanks,
Revital


      2007-12-06  Andrew Pinski  <andrew_pinski@playstation.sony.com>
            Mircea Namolaru  <namolaru@il.ibm.com>
            Vladimir Yanovsky  <yanov@il.ibm.com>>

        * tree-outof-ssa.c (analyze_edges_for_bb): Try to empty the
        latch bloack of a single-basic-block loop.
        (contains_tree_r): New function.

(See attached file: patch_empty_latch_6_12.txt)

Attachment: patch_empty_latch_6_12.txt
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