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* [Bug tree-optimization/21046] move memory allocation out of a loop [not found] <bug-21046-4@http.gcc.gnu.org/bugzilla/> @ 2012-02-22 12:49 ` xiaoyuanbo at yeah dot net 2014-12-25 12:16 ` tkoenig at gcc dot gnu.org 2020-11-11 9:22 ` tkoenig at gcc dot gnu.org 2 siblings, 0 replies; 6+ messages in thread From: xiaoyuanbo at yeah dot net @ 2012-02-22 12:49 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 xiaoyuanbo <xiaoyuanbo at yeah dot net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |xiaoyuanbo at yeah dot net --- Comment #4 from xiaoyuanbo <xiaoyuanbo at yeah dot net> 2012-02-22 12:42:13 UTC --- you know stack one ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21046] move memory allocation out of a loop [not found] <bug-21046-4@http.gcc.gnu.org/bugzilla/> 2012-02-22 12:49 ` [Bug tree-optimization/21046] move memory allocation out of a loop xiaoyuanbo at yeah dot net @ 2014-12-25 12:16 ` tkoenig at gcc dot gnu.org 2020-11-11 9:22 ` tkoenig at gcc dot gnu.org 2 siblings, 0 replies; 6+ messages in thread From: tkoenig at gcc dot gnu.org @ 2014-12-25 12:16 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 Thomas Koenig <tkoenig at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2010-04-29 09:33:08 |2014-12-25 CC| |tkoenig at gcc dot gnu.org --- Comment #5 from Thomas Koenig <tkoenig at gcc dot gnu.org> --- Any work being done on this? ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21046] move memory allocation out of a loop [not found] <bug-21046-4@http.gcc.gnu.org/bugzilla/> 2012-02-22 12:49 ` [Bug tree-optimization/21046] move memory allocation out of a loop xiaoyuanbo at yeah dot net 2014-12-25 12:16 ` tkoenig at gcc dot gnu.org @ 2020-11-11 9:22 ` tkoenig at gcc dot gnu.org 2 siblings, 0 replies; 6+ messages in thread From: tkoenig at gcc dot gnu.org @ 2020-11-11 9:22 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 Thomas Koenig <tkoenig at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2014-12-25 00:00:00 |2020-11-11 --- Comment #6 from Thomas Koenig <tkoenig at gcc dot gnu.org> --- Just thought to see if this has been fixed in the meantime; it's not optimized with current trunk. ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <bug-21046-10391@http.gcc.gnu.org/bugzilla/>]
* [Bug tree-optimization/21046] move memory allocation out of a loop [not found] <bug-21046-10391@http.gcc.gnu.org/bugzilla/> @ 2010-04-29 9:33 ` rguenth at gcc dot gnu dot org 0 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu dot org @ 2010-04-29 9:33 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from rguenth at gcc dot gnu dot org 2010-04-29 09:33 ------- I am working on this one (well, the first testcase kind). -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- BugsThisDependsOn| |42958 AssignedTo|unassigned at gcc dot gnu |rguenth at gcc dot gnu dot |dot org |org Status|NEW |ASSIGNED Last reconfirmed|2006-03-05 22:09:11 |2010-04-29 09:33:08 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21046] New: move memory allocation out of a loop @ 2005-04-15 12:42 tkoenig at gcc dot gnu dot org 2005-04-15 13:04 ` [Bug tree-optimization/21046] " giovannibajo at libero dot it 2005-04-15 13:37 ` pinskia at gcc dot gnu dot org 0 siblings, 2 replies; 6+ messages in thread From: tkoenig at gcc dot gnu dot org @ 2005-04-15 12:42 UTC (permalink / raw) To: gcc-bugs Consider the following program fragment: char *p; int i; for (i=0; i<10; i++) { p = malloc(20); foo(p,i); free(p); } } The loop could be simplified into p = malloc(20); for (i=0; i<10; i++) foo(p,i); free(p); This would reduce the overhead for memory allocation considerably. A more challenging case is to change for (i=0; i<10; i++) { p = malloc(2*i+2); foo(p,i); free(p); } into p = malloc(20); for (i=0; i<10; i++) foo(p,i); free(p); because the amount of memory allocated has an upper bound. This is probably not a big win for straight C code. For languages which generate temporary arrays at runtime, such as Fortran, it could mean a significant reduction in memory management overhead. -- Summary: move memory allocation out of a loop Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: enhancement Priority: P2 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: tkoenig at gcc dot gnu dot org CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21046] move memory allocation out of a loop 2005-04-15 12:42 [Bug tree-optimization/21046] New: " tkoenig at gcc dot gnu dot org @ 2005-04-15 13:04 ` giovannibajo at libero dot it 2005-04-15 13:37 ` pinskia at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: giovannibajo at libero dot it @ 2005-04-15 13:04 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From giovannibajo at libero dot it 2005-04-15 13:04 ------- I would think this is much more easily done in the frontend itself, which has a higher level representation so that it is much easier to hoist and reuse allocations. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21046] move memory allocation out of a loop 2005-04-15 12:42 [Bug tree-optimization/21046] New: " tkoenig at gcc dot gnu dot org 2005-04-15 13:04 ` [Bug tree-optimization/21046] " giovannibajo at libero dot it @ 2005-04-15 13:37 ` pinskia at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-04-15 13:37 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-04-15 13:37 ------- (In reply to comment #1) > I would think this is much more easily done in the frontend itself, which has a > higher level representation so that it is much easier to hoist and reuse > allocations. Not really true anymore. Confirmed, related to PR 19831. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Keywords| |missed-optimization Last reconfirmed|0000-00-00 00:00:00 |2005-04-15 13:37:14 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21046 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-11-11 9:22 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <bug-21046-4@http.gcc.gnu.org/bugzilla/> 2012-02-22 12:49 ` [Bug tree-optimization/21046] move memory allocation out of a loop xiaoyuanbo at yeah dot net 2014-12-25 12:16 ` tkoenig at gcc dot gnu.org 2020-11-11 9:22 ` tkoenig at gcc dot gnu.org [not found] <bug-21046-10391@http.gcc.gnu.org/bugzilla/> 2010-04-29 9:33 ` rguenth at gcc dot gnu dot org 2005-04-15 12:42 [Bug tree-optimization/21046] New: " tkoenig at gcc dot gnu dot org 2005-04-15 13:04 ` [Bug tree-optimization/21046] " giovannibajo at libero dot it 2005-04-15 13:37 ` pinskia at gcc dot gnu dot org
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