[patch] PR tree-optimization/26359 (creating memtags during vectorization)

[Dorit Nuzman <DORIT at il dot ibm dot com>]

Pass dce-loop is removing the entire body of the loop in the attached
testcase, after the loop has been vectorized, because
is_hidden_global_store returns false for the vectorized store stmt. This is
because the new memtag we create for the new vector pointer that is used in
the vectorized store is not marked as global. This patch fixes that, and
also sets other fields in the new memtag (inspired by the function
create_sft). Is this ok?

Bootstrapped and tested on the vectorizer testcases on powerpc-linux.

ok for mainline?

thanks,
dorit

:ADDPATCH SSA:

Changelog:
        PR tree-optimization/26359
        * tree-ssa-alias.c (new_type_alias): Set fields for new tag.

testsuite/Changelog:
        PR tree-optimizations/26359
        * gcc.dg/vect/vect.exp: Compile tests prefixed with
"dump-tree-dceloop"
        with -fdump-tree-dceloop-details.
        * gcc.dg/vect/dump-tree-dceloop-pr26359.c: New test.

(See attached file: pr26359.patch.txt)

Attachment: pr26359.patch.txt
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