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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/106912] [13 Regression] ICE in vect_transform_loops, at tree-vectorizer.cc:1032 since r13-1575-gcf3a120084e94614
Date: Mon, 12 Dec 2022 10:56:15 +0000 [thread overview]
Message-ID: <bug-106912-4-wd1sI4B12v@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-106912-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106912
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|rguenth at gcc dot gnu.org |unassigned at gcc dot gnu.org
Status|ASSIGNED |NEW
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #6)
> Sure, the FUNCTION_TYPE can be shared, so shouldn't be overwritten in place,
> but can be copied with TREE_READONLY cleared on the copy.
> So, if we for whatever reason need to clear const flag on some functions,
> after clearing TREE_READONLY on the node->decl we'd also need to update the
> TREE_TYPE to a version without TREE_READONLY set (so that say if new calls
> are created they don't get wrong fntype) and then walk all call edges to
> that function, updating gimple_call_fntype to the updated type if it was
> equal to the old TREE_TYPE, or to a copy with TREE_READONLY cleared if it
> has TREE_READONLY set on the FUNCTION/METHOD_TYPE).
That will not catch indirect calls to the function. So whatever we do
this part of the problem will remain (the out-of-sync profile). Like
inline int __attribute__((const))
foo (int i)
{
if (i == 0)
return 2;
return 1;
}
int (* __attribute__((const)) bar) () = foo;
int main()
{
int r = 0;
for (int i = 0; i < 10000; ++i)
{
r += foo (r);
r += bar (r);
}
return r;
}
which, when compiled with -O2 -fno-early-inlining -fprofile-arcs results
in the edge counters from the inline copy via foo to be store-motion'ed
but the indirect call clobbering them each iteration.
Using -fprofile-use prevents this because we get an indirect call profiler
call which clobbers all memory, confusing LIM, doing early inlining will
early inline the function before profile instrumentation.
I cannot see how we can fix this without some global flag to ignore
const/pure-ness of functions or alternatively dropping DECL_NONALIASED.
Trying to support surgical un-setting of pure/const for single functions
isn't going to work. Simply disabling IPA inlining for instrumented
builds might also work.
next prev parent reply other threads:[~2022-12-12 10:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-12 17:23 [Bug c/106912] New: [13 Regression] ICE in vect_transform_loops, at tree-vectorizer.cc:1032 gscfq@t-online.de
2022-09-12 19:35 ` [Bug tree-optimization/106912] [13 Regression] ICE in vect_transform_loops, at tree-vectorizer.cc:1032 since r13-1575-gcf3a120084e94614 marxin at gcc dot gnu.org
2022-09-13 6:41 ` rguenth at gcc dot gnu.org
2022-09-13 7:47 ` rguenth at gcc dot gnu.org
2022-09-13 8:51 ` rguenth at gcc dot gnu.org
2022-11-25 7:59 ` rguenth at gcc dot gnu.org
2022-12-08 17:30 ` jakub at gcc dot gnu.org
2022-12-12 10:56 ` rguenth at gcc dot gnu.org [this message]
2022-12-20 0:12 ` pinskia at gcc dot gnu.org
2023-02-06 12:11 ` jakub at gcc dot gnu.org
2023-02-06 12:29 ` jakub at gcc dot gnu.org
2023-02-07 11:33 ` rguenth at gcc dot gnu.org
2023-03-16 12:50 ` jakub at gcc dot gnu.org
2023-03-24 12:53 ` cvs-commit at gcc dot gnu.org
2023-03-24 12:54 ` rguenth at gcc dot gnu.org
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