[patch] Fix PR tree-optmization/50413

[Ira Rosen <ira dot rosen at linaro dot org>]

Hi,

When we can't vectorize a certain statement in SLP we mark it as not
vectorizable and continue with the analysis. This is wrong when the
reason for the failure is that we can't analyze a data-ref, because
this way we may miss a data dependence. This patch fails SLP if the
data-refs analysis fails.

Bootstrapped and tested on powerpc64-suse-linux and i486-linux-gnu.
Committed to trunk.

The same patch bootstrapped and tested on powerpc64-suse-linux for 4.6.
O.K. for 4.6?

Thanks,
Ira

ChangeLog:

        PR tree-optimization/50413
        * tree-vect-data-refs.c (vect_analyze_data_refs): Fail to vectorize
        a basic block if one of its data-refs can't be analyzed.

testsuite/ChangeLog:

        PR tree-optimization/50413
        * g++.dg/vect/vect.exp: Run slp-pr* tests with
        -fdump-tree-slp-details.  Run other tests with
        -fdump-tree-vect-details.
        * g++.dg/vect/slp-pr50413.cc: New.

Attachment: pr50413.txt
Description: Text document