public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug tree-optimization/22312] New: reassoc does not handle (i+j)+(k+l) well
@ 2005-07-05 18:33 pinskia at gcc dot gnu dot org
2005-07-05 19:02 ` [Bug tree-optimization/22312] " dberlin at dberlin dot org
2005-07-05 19:36 ` pinskia at gcc dot gnu dot org
0 siblings, 2 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-07-05 18:33 UTC (permalink / raw)
To: gcc-bugs
take the following example:
int f(int i, int j, int k, int l)
{
int r1 = (i+j)+(k+l);
int r2 = (j+k)+(l+i);
return r1 == r2;
}
This should return 1 all the time. I found this while making testcases for reassoc working fp (well I just
change one little thing to make it work really).
--
Summary: reassoc does not handle (i+j)+(k+l) well
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22312
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/22312] reassoc does not handle (i+j)+(k+l) well
2005-07-05 18:33 [Bug tree-optimization/22312] New: reassoc does not handle (i+j)+(k+l) well pinskia at gcc dot gnu dot org
@ 2005-07-05 19:02 ` dberlin at dberlin dot org
2005-07-05 19:36 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 4+ messages in thread
From: dberlin at dberlin dot org @ 2005-07-05 19:02 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dberlin at gcc dot gnu dot org 2005-07-05 19:02 -------
Subject: Re: New: reassoc does not handle
(i+j)+(k+l) well
On Tue, 2005-07-05 at 18:33 +0000, pinskia at gcc dot gnu dot org wrote:
> take the following example:
> int f(int i, int j, int k, int l)
> {
> int r1 = (i+j)+(k+l);
> int r2 = (j+k)+(l+i);
> return r1 == r2;
> }
>
> This should return 1 all the time. I found this while making testcases for reassoc working fp (well I just
> change one little thing to make it work really).
We can't do a full top-down reassocation because update_stmt reorders
our operands so we lose information about which is the high ranked
operand, etc.
It's a pain in the ass to fix, but possible.
>
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22312
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/22312] reassoc does not handle (i+j)+(k+l) well
2005-07-05 18:33 [Bug tree-optimization/22312] New: reassoc does not handle (i+j)+(k+l) well pinskia at gcc dot gnu dot org
2005-07-05 19:02 ` [Bug tree-optimization/22312] " dberlin at dberlin dot org
@ 2005-07-05 19:36 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-07-05 19:36 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-07-05 19:35 -------
Confirmed then.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-07-05 19:35:57
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22312
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/22312] reassoc does not handle (i+j)+(k+l) well
[not found] <bug-22312-6528@http.gcc.gnu.org/bugzilla/>
@ 2005-12-13 4:29 ` pinskia at gcc dot gnu dot org
0 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-12-13 4:29 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from pinskia at gcc dot gnu dot org 2005-12-13 04:29 -------
Fixed.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22312
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2005-12-13 4:29 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-07-05 18:33 [Bug tree-optimization/22312] New: reassoc does not handle (i+j)+(k+l) well pinskia at gcc dot gnu dot org
2005-07-05 19:02 ` [Bug tree-optimization/22312] " dberlin at dberlin dot org
2005-07-05 19:36 ` pinskia at gcc dot gnu dot org
[not found] <bug-22312-6528@http.gcc.gnu.org/bugzilla/>
2005-12-13 4:29 ` pinskia at gcc dot gnu dot org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).