[Bug tree-optimization/55124] [4.8 Regression] ICE in find_or_generate_expression, at tree-ssa-pre.c:2803

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55124

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> 2012-12-04 09:19:25 UTC ---
Author: rguenth
Date: Tue Dec  4 09:19:05 2012
New Revision: 194125

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=194125
Log:
2012-12-04  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/55124
    * tree-ssa-pre.c (find_or_generate_expression): Instead of
    ICEing when we are not able to generate an expression defer it
    by signalling failure.  Fix possible wrong-code issue by
    not picking random REFERENCE expressions as fallback.
    (create_component_ref_by_pieces_1): Adjust.  Add failure paths.
    (create_expression_by_pieces): Likewise.
    (insert_into_preds_of_block): When expression generation failed
    for one edge make sure to not insert a PHI node.

    * gcc.dg/torture/pr55124.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr55124.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-pre.c