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From: "linkw at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug testsuite/97705] [11 regression] cc.c-torture/unsorted/dump-noaddr.c.*r.ira fails after r11-4637
Date: Thu, 05 Nov 2020 05:58:19 +0000	[thread overview]
Message-ID: <bug-97705-4-rOP0prw39o@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-97705-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97705

--- Comment #4 from Kewen Lin <linkw at gcc dot gnu.org> ---
I think my commit just exposed one bug in ira. The newly introduced function
remove_scratches can bump the max_regno, then the data structures
regstat_n_sets_and_refs and reg_info_p which are allocated according to
max_regno become stale. When we call print_pseudo_costs to dump some register
information, it use the latest regno with max_reg_num (), it leads we can
access some regno which don't have relevant data structures which have been
allocated, the read values can be random (out of array bound access).

The fix can be to free/re-init/re-compute the relevant data structures when we
know the max_regno already changes like remove_scratches succeeds.

  parent reply	other threads:[~2020-11-05  5:58 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-03 16:28 [Bug other/97705] New: " seurer at gcc dot gnu.org
2020-11-03 17:15 ` [Bug other/97705] " seurer at gcc dot gnu.org
2020-11-04  2:11 ` linkw at gcc dot gnu.org
2020-11-04  8:10 ` [Bug testsuite/97705] " rguenth at gcc dot gnu.org
2020-11-04  9:42 ` linkw at gcc dot gnu.org
2020-11-05  5:58 ` linkw at gcc dot gnu.org [this message]
2020-11-09  4:28 ` [Bug rtl-optimization/97705] " cvs-commit at gcc dot gnu.org
2020-11-09  5:55 ` linkw at gcc dot gnu.org

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