[Bug tree-optimization/51879] Missed tail merging with non-const/pure calls

[vries at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51879

--- Comment #5 from vries at gcc dot gnu.org 2012-01-23 14:10:38 UTC ---
Created attachment 26430
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26430
Tentative patch

2012-01-23  Tom de Vries  <tom@codesourcery.com>

    PR tree-optimization/51879
    tree-ssa-sccvn.c (visit_reference_op_call): Handle gimple_vdef.
    (visit_use): Handle non-pure/const calls using visit_reference_op_call.

    gcc.dg/pr51879.c: New test.
    gcc.dg/pr51879-2.c: Same.
    gcc.dg/pr51879-3.c: Same.
    gcc.dg/pr51879-4.c: Same.