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* [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) [not found] <bug-16157-4@http.gcc.gnu.org/bugzilla/> @ 2012-03-04 0:06 ` pinskia at gcc dot gnu.org 0 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2012-03-04 0:06 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157 --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-03-04 00:06:13 UTC --- If we rewrite the code to be: extern int a0, a1, a2, a3, a4; extern int b0, b1, b2, b3, b4; void f () { /* this can be optimized to four additions... */ b4 = a4 + (a3 + (a2 + (a1 + a0))); b3 = a3 + (a2 + (a1 + a0)); b2 = a2 + (a1 + a0); b1 = a1 + a0; } Then it gets optimized. ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <bug-16157-7958@http.gcc.gnu.org/bugzilla/>]
* [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) [not found] <bug-16157-7958@http.gcc.gnu.org/bugzilla/> @ 2007-04-16 1:55 ` dberlin at gcc dot gnu dot org 2007-04-16 18:40 ` steven at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: dberlin at gcc dot gnu dot org @ 2007-04-16 1:55 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from dberlin at gcc dot gnu dot org 2007-04-16 02:55 ------- Don't remember if this is fixed, but not working anymore on it -- dberlin at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|dberlin at gcc dot gnu dot |unassigned at gcc dot gnu |org |dot org Status|ASSIGNED |NEW http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) [not found] <bug-16157-7958@http.gcc.gnu.org/bugzilla/> 2007-04-16 1:55 ` dberlin at gcc dot gnu dot org @ 2007-04-16 18:40 ` steven at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: steven at gcc dot gnu dot org @ 2007-04-16 18:40 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from steven at gcc dot gnu dot org 2007-04-16 19:40 ------- This is not yet fixed. -- steven at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2005-12-09 04:24:11 |2007-04-16 19:40:04 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157 ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <20040623133609.16157.belyshev@depni.sinp.msu.ru>]
* [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) [not found] <20040623133609.16157.belyshev@depni.sinp.msu.ru> @ 2005-07-26 13:14 ` dberlin at gcc dot gnu dot org 2005-08-28 20:00 ` dberlin at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: dberlin at gcc dot gnu dot org @ 2005-07-26 13:14 UTC (permalink / raw) To: gcc-bugs -- Bug 16157 depends on bug 21445, which changed state. Bug 21445 Summary: [meta-bug] we need a reassociate pass http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21445 What |Old Value |New Value ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) [not found] <20040623133609.16157.belyshev@depni.sinp.msu.ru> 2005-07-26 13:14 ` dberlin at gcc dot gnu dot org @ 2005-08-28 20:00 ` dberlin at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: dberlin at gcc dot gnu dot org @ 2005-08-28 20:00 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From dberlin at gcc dot gnu dot org 2005-08-28 19:59 ------- I have a patch for this -- What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|unassigned at gcc dot gnu |dberlin at gcc dot gnu dot |dot org |org Status|NEW |ASSIGNED Last reconfirmed|2005-03-23 02:58:54 |2005-08-28 19:59:28 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/16157] New: gcc fails to optimize redundant expression
@ 2004-06-23 13:56 belyshev at lubercy dot com
2004-12-22 4:15 ` [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) pinskia at gcc dot gnu dot org
0 siblings, 1 reply; 6+ messages in thread
From: belyshev at lubercy dot com @ 2004-06-23 13:56 UTC (permalink / raw)
To: gcc-bugs
extern int a0, a1, a2, a3, a4;
void f ()
{
/* this can be optimized to four additions... */
a4 = a4 + a3 + a2 + a1 + a0;
a3 = a3 + a2 + a1 + a0;
a2 = a2 + a1 + a0;
a1 = a1 + a0;
}
...but gcc does nothing with this function.
--
Summary: gcc fails to optimize redundant expression
Product: gcc
Version: 3.5.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: belyshev at lubercy dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) 2004-06-23 13:56 [Bug tree-optimization/16157] New: gcc fails to optimize redundant expression belyshev at lubercy dot com @ 2004-12-22 4:15 ` pinskia at gcc dot gnu dot org 0 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-12-22 4:15 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- CC| |pinskia at gcc dot gnu dot | |org Last reconfirmed|2004-09-22 13:16:11 |2004-12-22 04:15:13 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16157 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-03-04 0:06 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <bug-16157-4@http.gcc.gnu.org/bugzilla/>
2012-03-04 0:06 ` [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) pinskia at gcc dot gnu.org
[not found] <bug-16157-7958@http.gcc.gnu.org/bugzilla/>
2007-04-16 1:55 ` dberlin at gcc dot gnu dot org
2007-04-16 18:40 ` steven at gcc dot gnu dot org
[not found] <20040623133609.16157.belyshev@depni.sinp.msu.ru>
2005-07-26 13:14 ` dberlin at gcc dot gnu dot org
2005-08-28 20:00 ` dberlin at gcc dot gnu dot org
2004-06-23 13:56 [Bug tree-optimization/16157] New: gcc fails to optimize redundant expression belyshev at lubercy dot com
2004-12-22 4:15 ` [Bug tree-optimization/16157] gcc fails to optimize redundant expression (reassocation) pinskia at gcc dot gnu dot org
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