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* [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code
@ 2014-02-16 3:46 redlizard at redlizard dot nl
2014-02-16 4:55 ` [Bug middle-end/60221] " pinskia at gcc dot gnu.org
` (10 more replies)
0 siblings, 11 replies; 12+ messages in thread
From: redlizard at redlizard dot nl @ 2014-02-16 3:46 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Bug ID: 60221
Summary: gcc -fexceptions generates unnecessary cleanup code
Product: gcc
Version: 4.8.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: redlizard at redlizard dot nl
> gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/tmp/gcc-4.8.2/libexec/gcc/x86_64-unknown-linux-gnu/4.8.2/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-4.8.2/configure --prefix=/tmp/gcc-4.8.2
--enable-languages=c,c++
Thread model: posix
gcc version 4.8.2 (GCC)
> cat test.c
void bar(void);
void foo(void)
{
struct { int x; } y;
bar();
}
When compiled with `gcc -fexceptions -O0 -c test.c`, the above code generates
cleanup code for stack unwinding purposes, referencing __gcc_personality_v0;
this necessitates linking with shared-libgcc.
I am not sure this is really a bug, but versions of gcc older than 4.7 do not
generate cleanup code for this example; neither does gcc 4.8 when the local
variable is replaced by `int y;`. Moreover, according to the gcc documentation,
there are "several situations" (I have been unable to find more a detailed
specification) in which linking with shared-libgcc is necessary, which includes
code throwing or catching exceptions, but should -- as far as I can see --
*not* include c code just passing through exceptions.
Tested on x86_64-unknown-linux-gnu, x86_64-unknown-linux-gnu -m32, and
i386-pc-solaris2.11, using gcc 4.7.1, 4.7.3, and 4.8.2. gcc 4.6.4 and earlier
tested versions are not affected. I have been unable to test gcc 4.7.0.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
@ 2014-02-16 4:55 ` pinskia at gcc dot gnu.org
2014-02-17 12:32 ` [Bug middle-end/60221] [4.7/4.8/4.9 Regression] " rguenth at gcc dot gnu.org
` (9 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: pinskia at gcc dot gnu.org @ 2014-02-16 4:55 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Component|c |middle-end
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Still fails as of:
.ident "GCC: (GNU) 4.9.0 20131110 (experimental) [trunk revision
204654]"
I thought I saw a dup of this bug. It is just a missed optimization at -O0
which was introduced by the addition of the CLOBBERing of local non-scalars.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8/4.9 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
2014-02-16 4:55 ` [Bug middle-end/60221] " pinskia at gcc dot gnu.org
@ 2014-02-17 12:32 ` rguenth at gcc dot gnu.org
2014-02-17 15:41 ` jakub at gcc dot gnu.org
` (8 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-17 12:32 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |EH
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-02-17
CC| |hubicka at gcc dot gnu.org,
| |matz at gcc dot gnu.org
Target Milestone|--- |4.7.4
Summary|gcc -fexceptions generates |[4.7/4.8/4.9 Regression]
|unnecessary cleanup code |gcc -fexceptions generates
| |unnecessary cleanup code
Ever confirmed|0 |1
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8/4.9 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
2014-02-16 4:55 ` [Bug middle-end/60221] " pinskia at gcc dot gnu.org
2014-02-17 12:32 ` [Bug middle-end/60221] [4.7/4.8/4.9 Regression] " rguenth at gcc dot gnu.org
@ 2014-02-17 15:41 ` jakub at gcc dot gnu.org
2014-02-18 10:41 ` rguenth at gcc dot gnu.org
` (7 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: jakub at gcc dot gnu.org @ 2014-02-17 15:41 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I'm not aware of a dup, but this has been recently discussed on gcc-patches,
see the
http://gcc.gnu.org/ml/gcc-patches/2014-01/msg01200.html
thread.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8/4.9 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (2 preceding siblings ...)
2014-02-17 15:41 ` jakub at gcc dot gnu.org
@ 2014-02-18 10:41 ` rguenth at gcc dot gnu.org
2014-02-20 9:01 ` rguenth at gcc dot gnu.org
` (6 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-18 10:41 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Note that we do run ehcleanup2 at -O0, but we have EH unsplitting and empty
EH removal disabled if not optimizing.
So we could simply do
Index: tree-eh.c
===================================================================
--- tree-eh.c (revision 207837)
+++ tree-eh.c (working copy)
@@ -4557,11 +4557,12 @@ execute_cleanup_eh_1 (void)
remove_unreachable_handlers ();
/* Watch out for the region tree vanishing due to all unreachable. */
- if (cfun->eh->region_tree && optimize)
+ if (cfun->eh->region_tree)
{
bool changed = false;
- changed |= unsplit_all_eh ();
+ if (optimize)
+ changed |= unsplit_all_eh ();
changed |= cleanup_all_empty_eh ();
if (changed)
Testing that.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8/4.9 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (3 preceding siblings ...)
2014-02-18 10:41 ` rguenth at gcc dot gnu.org
@ 2014-02-20 9:01 ` rguenth at gcc dot gnu.org
2014-02-20 22:09 ` [Bug middle-end/60221] [4.7/4.8 " redlizard at redlizard dot nl
` (5 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-20 9:01 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Thu Feb 20 09:00:23 2014
New Revision: 207937
URL: http://gcc.gnu.org/viewcvs?rev=207937&root=gcc&view=rev
Log:
2014-02-20 Richard Biener <rguenther@suse.de>
PR middle-end/60221
* tree-eh.c (execute_cleanup_eh_1): Also cleanup empty EH
regions at -O0.
Modified:
trunk/gcc/ChangeLog
trunk/gcc/tree-eh.c
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (4 preceding siblings ...)
2014-02-20 9:01 ` rguenth at gcc dot gnu.org
@ 2014-02-20 22:09 ` redlizard at redlizard dot nl
2014-02-21 9:16 ` rguenther at suse dot de
` (4 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: redlizard at redlizard dot nl @ 2014-02-20 22:09 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
--- Comment #6 from Ruud Koolen <redlizard at redlizard dot nl> ---
This fix solves my original problem. Resolved, as far as I'm concerned.
Will this fix also be applied to 4.7 and 4.8?
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (5 preceding siblings ...)
2014-02-20 22:09 ` [Bug middle-end/60221] [4.7/4.8 " redlizard at redlizard dot nl
@ 2014-02-21 9:16 ` rguenther at suse dot de
2014-02-25 10:47 ` rguenth at gcc dot gnu.org
` (3 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenther at suse dot de @ 2014-02-21 9:16 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
--- Comment #7 from rguenther at suse dot de <rguenther at suse dot de> ---
On Thu, 20 Feb 2014, redlizard at redlizard dot nl wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
>
> --- Comment #6 from Ruud Koolen <redlizard at redlizard dot nl> ---
> This fix solves my original problem. Resolved, as far as I'm concerned.
>
> Will this fix also be applied to 4.7 and 4.8?
After some time and no problems show up, yes. I expect it to hit
4.8.3 at least, not sure about 4.7.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7/4.8 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (6 preceding siblings ...)
2014-02-21 9:16 ` rguenther at suse dot de
@ 2014-02-25 10:47 ` rguenth at gcc dot gnu.org
2014-02-25 10:48 ` [Bug middle-end/60221] [4.7 " rguenth at gcc dot gnu.org
` (2 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-25 10:47 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Feb 25 10:47:21 2014
New Revision: 208118
URL: http://gcc.gnu.org/viewcvs?rev=208118&root=gcc&view=rev
Log:
2014-02-25 Richard Biener <rguenther@suse.de>
Backport from mainline
2014-02-21 Richard Biener <rguenther@suse.de>
PR middle-end/60291
* tree-ssa-live.c (mark_all_vars_used_1): Do not walk
DECL_INITIAL for globals not in the current function context.
2014-02-20 Richard Biener <rguenther@suse.de>
PR middle-end/60221
* tree-eh.c (execute_cleanup_eh_1): Also cleanup empty EH
regions at -O0.
2014-02-14 Richard Biener <rguenther@suse.de>
PR tree-optimization/60183
* tree-ssa-phiprop.c (propagate_with_phi): Avoid speculating
loads.
(tree_ssa_phiprop): Calculate and free post-dominators.
* gcc.dg/torture/pr60183.c: New testcase.
Added:
branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/torture/pr60183.c
Modified:
branches/gcc-4_8-branch/gcc/ChangeLog
branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
branches/gcc-4_8-branch/gcc/tree-eh.c
branches/gcc-4_8-branch/gcc/tree-ssa-live.c
branches/gcc-4_8-branch/gcc/tree-ssa-phiprop.c
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (7 preceding siblings ...)
2014-02-25 10:47 ` rguenth at gcc dot gnu.org
@ 2014-02-25 10:48 ` rguenth at gcc dot gnu.org
2014-03-09 19:00 ` pinskia at gcc dot gnu.org
2014-05-23 8:27 ` rguenth at gcc dot gnu.org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-02-25 10:48 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |4.8.3
Summary|[4.7/4.8 Regression] gcc |[4.7 Regression] gcc
|-fexceptions generates |-fexceptions generates
|unnecessary cleanup code |unnecessary cleanup code
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
And for 4.8.3.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (8 preceding siblings ...)
2014-02-25 10:48 ` [Bug middle-end/60221] [4.7 " rguenth at gcc dot gnu.org
@ 2014-03-09 19:00 ` pinskia at gcc dot gnu.org
2014-05-23 8:27 ` rguenth at gcc dot gnu.org
10 siblings, 0 replies; 12+ messages in thread
From: pinskia at gcc dot gnu.org @ 2014-03-09 19:00 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |zosrothko at orange dot fr
--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 60475 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/60221] [4.7 Regression] gcc -fexceptions generates unnecessary cleanup code
2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
` (9 preceding siblings ...)
2014-03-09 19:00 ` pinskia at gcc dot gnu.org
@ 2014-05-23 8:27 ` rguenth at gcc dot gnu.org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-05-23 8:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60221
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
Target Milestone|4.7.4 |4.8.3
--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Won't fix for 4.7.4.
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2014-05-23 8:27 UTC | newest]
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2014-02-16 3:46 [Bug c/60221] New: gcc -fexceptions generates unnecessary cleanup code redlizard at redlizard dot nl
2014-02-16 4:55 ` [Bug middle-end/60221] " pinskia at gcc dot gnu.org
2014-02-17 12:32 ` [Bug middle-end/60221] [4.7/4.8/4.9 Regression] " rguenth at gcc dot gnu.org
2014-02-17 15:41 ` jakub at gcc dot gnu.org
2014-02-18 10:41 ` rguenth at gcc dot gnu.org
2014-02-20 9:01 ` rguenth at gcc dot gnu.org
2014-02-20 22:09 ` [Bug middle-end/60221] [4.7/4.8 " redlizard at redlizard dot nl
2014-02-21 9:16 ` rguenther at suse dot de
2014-02-25 10:47 ` rguenth at gcc dot gnu.org
2014-02-25 10:48 ` [Bug middle-end/60221] [4.7 " rguenth at gcc dot gnu.org
2014-03-09 19:00 ` pinskia at gcc dot gnu.org
2014-05-23 8:27 ` rguenth at gcc dot gnu.org
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