Re: [PATCH, middle-end]: Fix PR tree-optimization/{31966, 32533}

["Richard Guenther" <richard dot guenther at gmail dot com>]

On 7/2/07, Richard Guenther <richard.guenther@gmail.com> wrote:
> On 7/2/07, Uros Bizjak <ubizjak@gmail.com> wrote:
> > Hello!
> >
> > As described in great detail in PR 31966, Comment #7 and Comment #6,
> > there is a nasty bug in tree-if-convert.c. When a bb with condition
> > code directly feeds bb with a phi node, current implementation
> > "forgets" to account for the condition for the branch that leads to
> > the phi node [see PR for further explanation and for the proof].
> >
> > The patch fixes this by attaching a condition of true or false arm to
> > relevant edge. When constructing equivalent condition for phi node,
> > incoming edges are checked if there is a condition attached to them,
> > and in this case equivalent condition is constructed by boolean AND of
> > successor block predicate and edge condition.
> >
> > The patch has been checked on i686-pc-linux-gnu on  gcc-41 and gcc-42
> > branches, as well as mainline, for all default languages. It fixes two
> > PRs and (as reported in PR32533) fixes a bunch of failing CP2K
> > testcases.
> >
> > OK for mainline and 4.1 and 4.2 branch?
>
> This is ok.  Please let it have a few days on mainline before committing
> to the branches.
>
> Thanks,
> Richard.
>
> > 2007-07-02  Uros Bizjak  <ubizjak@gmail.com>
> >
> >         PR tree-optimization/31966
> >         PR tree-optimization/32533
> >         * tree-if-conv.c (add_to_dst_predicate_list): Use "edge", not
> >         "basic_block" description as its third argument.  Update function
> >         calls to get destination bb from "edge" argument.  Save "cond" into
> >         aux field of the edge.  Update prototype for changed arguments.
> >         (find_phi_replacement_condition): Operate on incoming edges, not
> >         on predecessor blocks.  If there is a condition saved in the
> >         incoming edge aux field, AND it with incoming bb predicate.
> >         Return source bb of the first edge.
> >         (clean_predicate_lists): Clean aux field of outgoing node edges.
> >         (tree_if_conversion): Do not initialize cond variable. Move
> >         variable declaration into the loop.
> >         (replace_phi_with_cond_gimple_modify_stmt): Remove unneded
> >         initializations of new_stmt, arg0 and arg1 variables.
> >
> > testsuite/ChangeLog:
> >
> > 2007-07-02  Uros Bizjak  <ubizjak@gmail.com>
> >
> >         PR tree-optimization/31966
> >         PR tree-optimization/32533
> >         * gcc.dg/tree-ssa/pr31966.c: New runtime test.
> >         * gfortran.dg/pr32533.f90: Ditto.

On the 4.2 branch the testcase for PR32533 ICEs:

/abuild/rguenther/gcc-4_2-branch/gcc/testsuite/gfortran.dg/pr32533.f90:
In function 't':^M
/abuild/rguenther/gcc-4_2-branch/gcc/testsuite/gfortran.dg/pr32533.f90:6:
error: incorrect sharing of tree nodes^M
D.1370_44 = M.2D.1253_16 > 1;^M
^M
M.2D.1253_16 > 1;^M
^M
/abuild/rguenther/gcc-4_2-branch/gcc/testsuite/gfortran.dg/pr32533.f90:6:
internal compiler error: verify_stmts failed^M
Please submit a full bug report,^M
with preprocessed source if appropriate.^M
See <URL:http://gcc.gnu.org/bugs.html> for instructions.^M

Richard.