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* [Bug c++/51060] New: Temporary object stack space is not re-used @ 2011-11-09 14:11 andvgal at gmail dot com 2011-11-09 14:46 ` [Bug c++/51060] " rguenth at gcc dot gnu.org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: andvgal at gmail dot com @ 2011-11-09 14:11 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51060 Bug #: 51060 Summary: Temporary object stack space is not re-used Classification: Unclassified Product: gcc Version: 4.6.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: andvgal@gmail.com Created attachment 25769 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25769 10 tmp objects of 1KB in size produce 10KB frame I've tried hard finding a related incident, the only one close to it is PR 16269, but its solution doesn't help. Attached is a sample test, which allocates 10 temporary objects of 1KB size in own blocks in the same function. If compiled with "-Wframe-larger-than=2048 -Werror -Os" (-Oany) the following warning is produced: warning: the frame size of 10240 bytes is larger than 2048 bytes [-Wframe-larger-than=] In our case, function frames are blown away for 100+KB, what makes a code with similar pattern absolutely unusable in embedded systems. Reproduced on GCC 4.6.1 x86_64 @ Debian and custom built GCC 4.6.2 for ARM. The same issue exists in GCC 4.3.x for ARM. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/51060] Temporary object stack space is not re-used 2011-11-09 14:11 [Bug c++/51060] New: Temporary object stack space is not re-used andvgal at gmail dot com @ 2011-11-09 14:46 ` rguenth at gcc dot gnu.org 2011-11-11 21:57 ` jason at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2011-11-09 14:46 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51060 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2011-11-09 CC| |jason at redhat dot com, | |matz at gcc dot gnu.org Ever Confirmed|0 |1 --- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-11-09 14:41:24 UTC --- Confirmed. The new death-point stuff doesn't help as the frontend does not seem to construct scopes properly for this testcase. ;; Function void Test() (null) ;; enabled by -tree-original <<cleanup_point <<< Unknown tree: expr_stmt (void) TARGET_EXPR <D.21343, <<< Unknown tree: aggr_init_expr 4 __comp_ctor D.21343 0B >>>> >>>>>; <<cleanup_point <<< Unknown tree: expr_stmt (void) TARGET_EXPR <D.21344, <<< Unknown tree: aggr_init_expr 4 __comp_ctor D.21344 0B >>>> >>>>>; ... ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/51060] Temporary object stack space is not re-used 2011-11-09 14:11 [Bug c++/51060] New: Temporary object stack space is not re-used andvgal at gmail dot com 2011-11-09 14:46 ` [Bug c++/51060] " rguenth at gcc dot gnu.org @ 2011-11-11 21:57 ` jason at gcc dot gnu.org 2011-11-13 1:20 ` jason at gcc dot gnu.org 2011-11-13 2:06 ` jason at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: jason at gcc dot gnu.org @ 2011-11-11 21:57 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51060 Jason Merrill <jason at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED CC| |jason at gcc dot gnu.org AssignedTo|unassigned at gcc dot |jason at gcc dot gnu.org |gnu.org | --- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-11 21:50:29 UTC --- We already deal with cleanups for temporary objects, it should be pretty simple to add the death clobber that way. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/51060] Temporary object stack space is not re-used 2011-11-09 14:11 [Bug c++/51060] New: Temporary object stack space is not re-used andvgal at gmail dot com 2011-11-09 14:46 ` [Bug c++/51060] " rguenth at gcc dot gnu.org 2011-11-11 21:57 ` jason at gcc dot gnu.org @ 2011-11-13 1:20 ` jason at gcc dot gnu.org 2011-11-13 2:06 ` jason at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: jason at gcc dot gnu.org @ 2011-11-13 1:20 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51060 --- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-13 00:44:43 UTC --- Author: jason Date: Sun Nov 13 00:44:39 2011 New Revision: 181332 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181332 Log: PR c++/51060 * gimplify.c (gimplify_target_expr): Add a clobber to the cleanup. (gimplify_modify_expr): Don't try to simplify it. * cp/cp-gimplify.c (cp_gimplify_expr): Leave clobbers alone. Added: trunk/gcc/testsuite/g++.dg/opt/stack2.C Modified: trunk/gcc/ChangeLog trunk/gcc/cp/ChangeLog trunk/gcc/cp/cp-gimplify.c trunk/gcc/gimplify.c trunk/gcc/testsuite/ChangeLog trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/testsuite/25_algorithms/max/1.cc trunk/libstdc++-v3/testsuite/25_algorithms/min/1.cc trunk/libstdc++-v3/testsuite/25_algorithms/minmax/1.cc ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/51060] Temporary object stack space is not re-used 2011-11-09 14:11 [Bug c++/51060] New: Temporary object stack space is not re-used andvgal at gmail dot com ` (2 preceding siblings ...) 2011-11-13 1:20 ` jason at gcc dot gnu.org @ 2011-11-13 2:06 ` jason at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: jason at gcc dot gnu.org @ 2011-11-13 2:06 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51060 Jason Merrill <jason at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution| |FIXED Target Milestone|--- |4.7.0 --- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-13 00:47:26 UTC --- Indeed, pretty simple now that we have that infrastructure. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2011-11-13 0:48 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-11-09 14:11 [Bug c++/51060] New: Temporary object stack space is not re-used andvgal at gmail dot com 2011-11-09 14:46 ` [Bug c++/51060] " rguenth at gcc dot gnu.org 2011-11-11 21:57 ` jason at gcc dot gnu.org 2011-11-13 1:20 ` jason at gcc dot gnu.org 2011-11-13 2:06 ` jason at gcc dot gnu.org
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