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From: "sandra at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/64231] [5 Regression] SIGSEGV building glibc on aarch64-linux-gnu from r217852 Date: Tue, 09 Dec 2014 21:27:00 -0000 [thread overview] Message-ID: <bug-64231-4-M8FJZra912@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-64231-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64231 --- Comment #7 from Sandra Loosemore <sandra at codesourcery dot com> --- Hmmmm. I'm not sure why there's trouble in reproducing the failure, but looking at this some more, it seems like we have a problem with this code fragment from force_const_mem in varasm.c: /* If we're not allowed to drop X into the constant pool, don't. */ if (targetm.cannot_force_const_mem (mode, x)) return NULL_RTX; and the code at the call site in plus_constant in explow.c: tem = force_const_mem (GET_MODE (x), tem); if (memory_address_p (GET_MODE (tem), XEXP (tem, 0))) return tem; which is clearly not expecting force_const_mem to return null. Guarding the reference in the conditional like if (tem && memory_address_p (GET_MODE (tem), XEXP (tem, 0))) ... fixes the SEGV, but a quick look shows that there are a lot of other uses of force_const_mem that expect it to return a non-null value, with no checking. So, probably this has nothing to do with the specific change in r217852, but has been a lurking bug for a long time, and it needs more than a band-aid on this one particular call site.
next prev parent reply other threads:[~2014-12-09 21:27 UTC|newest] Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-12-09 1:43 [Bug target/64231] New: " sandra at codesourcery dot com 2014-12-09 1:47 ` [Bug target/64231] " pinskia at gcc dot gnu.org 2014-12-09 1:48 ` pinskia at gcc dot gnu.org 2014-12-09 3:16 ` sandra at codesourcery dot com 2014-12-09 3:19 ` sandra at codesourcery dot com 2014-12-09 9:23 ` ktkachov at gcc dot gnu.org 2014-12-09 12:38 ` [Bug target/64231] [5 Regression] " rguenth at gcc dot gnu.org 2014-12-09 16:54 ` sandra at codesourcery dot com 2014-12-09 21:27 ` sandra at codesourcery dot com [this message] 2014-12-15 15:54 ` belagod at gcc dot gnu.org 2015-01-13 14:26 ` ramana at gcc dot gnu.org 2015-01-13 14:31 ` pinskia at gcc dot gnu.org 2015-01-13 15:05 ` ramana at gcc dot gnu.org 2015-01-13 15:10 ` sandra at codesourcery dot com 2015-01-15 14:39 ` belagod at gcc dot gnu.org 2015-01-15 16:28 ` belagod at gcc dot gnu.org 2015-01-21 2:41 ` pinskia at gcc dot gnu.org 2015-01-21 8:11 ` jakub at gcc dot gnu.org 2015-01-22 14:18 ` jakub at gcc dot gnu.org 2015-01-23 10:27 ` ramana at gcc dot gnu.org 2015-02-02 15:55 ` belagod at gcc dot gnu.org 2015-02-02 15:59 ` belagod at gcc dot gnu.org 2015-04-15 8:12 ` clyon at gcc dot gnu.org
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