[Bug tree-optimization/98736] [10 Regression] Wrong partition order generated in loop distribution pass since r10-619-g5879ab5fafedc8f6

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98736

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:6c6a1173cccfd9c466e43bafa7ef7940b93d1495

commit r10-9758-g6c6a1173cccfd9c466e43bafa7ef7940b93d1495
Author: Bin Cheng <bin.cheng@linux.alibaba.com>
Date:   Wed Apr 7 10:24:32 2021 +0800

    tree-optimization/98736 - use programing order preserved RPO in ldist

    Tree loop distribution uses RPO to build reduced dependence graph,
    it's important that RPO preserves the original programing order.
    Though it usually does so, when distributing loop nest, exit BB can
    be placed before some loop BBs while after loop header.  This patch
    fixes the issue by calling rev_post_order_and_mark_dfs_back_seme.

    gcc/ChangeLog:

            PR tree-optimization/98736
            * tree-loop-distribution.c
            * (loop_distribution::bb_top_order_init):
            Compute RPO with programing order preserved by calling function
            rev_post_order_and_mark_dfs_back_seme.

    gcc/testsuite/ChangeLog:

            PR tree-optimization/98736
            * gcc.c-torture/execute/pr98736.c: New test.

    (cherry picked from commit e0bdccac582c01c928a05f26edcd8f5ac24669eb)