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* [Bug optimization/15357] New: [tree-ssa] combing if statements
@ 2004-05-09 22:11 pinskia at gcc dot gnu dot org
2004-05-09 22:20 ` [Bug optimization/15357] " pinskia at gcc dot gnu dot org
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-09 22:11 UTC (permalink / raw)
To: gcc-bugs
The following two functions should give the same asm (If the branch cost is high
enough):
int g(void);
int h(int a, int b, int c, int d)
{
if (a==b)
if (c==d)
return g();
return 0;
}
int h1(int a, int b, int c, int d)
{
if (a==b && c==d)
return g();
return 0;
}
And these two:
int j(int a, int b, int c, int d)
{
if (a==b)
goto a;
if (c==d)
goto a;
else
goto b;
a:
return g();
b:
return 0;
}
int j1(int a, int b, int c, int d)
{
if (a==b || c==d)
return g();
return 0;
}
--
Summary: [tree-ssa] combing if statements
Product: gcc
Version: tree-ssa
Status: UNCONFIRMED
Keywords: pessimizes-code, memory-hog, compile-time-hog
Severity: enhancement
Priority: P2
Component: optimization
AssignedTo: pinskia at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
OtherBugsDependingO 15241,15348,15352
nThis:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug optimization/15357] [tree-ssa] combing if statements
2004-05-09 22:11 [Bug optimization/15357] New: [tree-ssa] combing if statements pinskia at gcc dot gnu dot org
@ 2004-05-09 22:20 ` pinskia at gcc dot gnu dot org
2004-05-25 0:09 ` [Bug tree-optimization/15357] " pinskia at gcc dot gnu dot org
2005-05-08 18:17 ` pinskia at gcc dot gnu dot org
2 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-09 22:20 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-05-09 22:20 -------
Mine I am working on this, then we should be able to removed this optimization in fold
which causes this to happen in the one statement one.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2004-05-09 22:20:20
date| |
Target Milestone|--- |tree-ssa
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/15357] [tree-ssa] combing if statements
2004-05-09 22:11 [Bug optimization/15357] New: [tree-ssa] combing if statements pinskia at gcc dot gnu dot org
2004-05-09 22:20 ` [Bug optimization/15357] " pinskia at gcc dot gnu dot org
@ 2004-05-25 0:09 ` pinskia at gcc dot gnu dot org
2005-05-08 18:17 ` pinskia at gcc dot gnu dot org
2 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-25 0:09 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|3.5.0 |---
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/15357] [tree-ssa] combing if statements
2004-05-09 22:11 [Bug optimization/15357] New: [tree-ssa] combing if statements pinskia at gcc dot gnu dot org
2004-05-09 22:20 ` [Bug optimization/15357] " pinskia at gcc dot gnu dot org
2004-05-25 0:09 ` [Bug tree-optimization/15357] " pinskia at gcc dot gnu dot org
@ 2005-05-08 18:17 ` pinskia at gcc dot gnu dot org
2 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-05-08 18:17 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-08 18:17 -------
I lost the code which I was using to do this so I am no longer working on this.
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|pinskia 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=15357
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/15357] [tree-ssa] combing if statements
[not found] <bug-15357-4@http.gcc.gnu.org/bugzilla/>
2012-01-21 22:11 ` pinskia at gcc dot gnu.org
@ 2013-11-09 20:40 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu.org @ 2013-11-09 20:40 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
Target Milestone|--- |4.9.0
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed by:
2013-10-29 Andrew Pinski <apinski@cavium.com>
* tree-ssa-ifcombine.c: Include rtl.h and tm_p.h.
(ifcombine_ifandif): Handle cases where maybe_fold_and_comparisons
fails, combining the branches anyways.
(tree_ssa_ifcombine): Inverse the order of the basic block walk,
increases the number of combinings.
* gimple.h (gsi_start_nondebug_after_labels_bb): New function.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/15357] [tree-ssa] combing if statements
[not found] <bug-15357-4@http.gcc.gnu.org/bugzilla/>
@ 2012-01-21 22:11 ` pinskia at gcc dot gnu.org
2013-11-09 20:40 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu.org @ 2012-01-21 22:11 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
AssignedTo|unassigned at gcc dot |pinskia at gcc dot gnu.org
|gnu.org |
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-01-21 22:02:24 UTC ---
I have a patch which implements this. I will be posting it for 4.8.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/15357] [tree-ssa] combing if statements
[not found] <bug-15357-6528@http.gcc.gnu.org/bugzilla/>
2007-01-26 13:44 ` rguenth at gcc dot gnu dot org
@ 2007-06-12 12:10 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2007-06-12 12:10 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from rguenth at gcc dot gnu dot org 2007-06-12 12:10 -------
The new if-combining pass can be told to make the transformation suggested in
the description.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug tree-optimization/15357] [tree-ssa] combing if statements
[not found] <bug-15357-6528@http.gcc.gnu.org/bugzilla/>
@ 2007-01-26 13:44 ` rguenth at gcc dot gnu dot org
2007-06-12 12:10 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2007-01-26 13:44 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from rguenth at gcc dot gnu dot org 2007-01-26 13:44 -------
Another thing we should be able to do is combine bit-tests like
if (a & (1 << b))
if (a & (1 << c))
...
to a single test
if (a & ((1 << b) | (1 << c)) == ((1 << b) | (1 << c)))
...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2013-11-09 20:39 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-05-09 22:11 [Bug optimization/15357] New: [tree-ssa] combing if statements pinskia at gcc dot gnu dot org
2004-05-09 22:20 ` [Bug optimization/15357] " pinskia at gcc dot gnu dot org
2004-05-25 0:09 ` [Bug tree-optimization/15357] " pinskia at gcc dot gnu dot org
2005-05-08 18:17 ` pinskia at gcc dot gnu dot org
[not found] <bug-15357-6528@http.gcc.gnu.org/bugzilla/>
2007-01-26 13:44 ` rguenth at gcc dot gnu dot org
2007-06-12 12:10 ` rguenth at gcc dot gnu dot org
[not found] <bug-15357-4@http.gcc.gnu.org/bugzilla/>
2012-01-21 22:11 ` pinskia at gcc dot gnu.org
2013-11-09 20:40 ` pinskia at gcc dot gnu.org
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