Re: Merge stores/loads in modref summaries

[Jeff Law via Gcc-patches]

On 8/26/2021 11:10 AM, Jan Hubicka wrote:
commit f075b8c5adcf9cb6336563c472c8d624c54184db
Author: Jan Hubicka <hubi...@ucw.cz>
Date:   Thu Aug 26 15:33:56 2021 +0200

     Fix off-by-one error in try_merge_with

     gcc/ChangeLog:

             * ipa-modref-tree.h (modref_ref_node::verify): New member
             functoin.
             (modref_ref_node::insert): Use it.
             (modref_ref_node::try_mere_with): Fix off by one error.

caused libgo build failure on Linux/i686:
Sorry for that.  Jeff sent me independent testcase and it seems to be
same problem.  It turns out that after merging two access ranges one
needs to restart the walk since after this earlier access ranges may
merge or be contained in the bigger range produced. I missed this case
and apologize for it.

        * ipa-modref-tree.h (modref_access_node::try_merge_with): Restart
        search after merging.
FWIW, the 4 toolchains I built that were previously failing during their 
kernel build now pass their kernel build with this patch.  Two fail 
their testsuite, but I strongly suspect that's an independent issue.

Jeff