public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed
@ 2004-01-21 20:32 dann at godzilla dot ics dot uci dot edu
2004-01-21 21:46 ` [Bug optimization/13799] " pinskia at gcc dot gnu dot org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: dann at godzilla dot ics dot uci dot edu @ 2004-01-21 20:32 UTC (permalink / raw)
To: gcc-bugs
int foo11 (int c)
{
static int local1, local2;
local1 = 0;
local2 += c;
local1 = 2;
local2++;
return local1 + local2;
}
There should be 1 store to local2, local1 should be eliminated.
the .optimized dump:
foo11 (c)
{
static int local2;
static int local1;
int T.7;
<bb 0>:
local1 = 0;
local2 = c;
local1 = 2;
T.7 = c + 1;
local2 = T.7;
return T.7 + 2;
}
--
Summary: [tree-ssa] consecutive stores to static vars not removed
Product: gcc
Version: tree-ssa
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dann at godzilla dot ics dot uci dot edu
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13799
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug optimization/13799] [tree-ssa] consecutive stores to static vars not removed
2004-01-21 20:32 [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed dann at godzilla dot ics dot uci dot edu
@ 2004-01-21 21:46 ` pinskia at gcc dot gnu dot org
2004-02-16 22:05 ` law at gcc dot gnu dot org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-21 21:46 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-01-21 21:46 -------
Confirmed, PTA does not help either.
--
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Keywords| |pessimizes-code
Last reconfirmed|0000-00-00 00:00:00 |2004-01-21 21:46:20
date| |
Target Milestone|--- |tree-ssa
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13799
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug optimization/13799] [tree-ssa] consecutive stores to static vars not removed
2004-01-21 20:32 [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed dann at godzilla dot ics dot uci dot edu
2004-01-21 21:46 ` [Bug optimization/13799] " pinskia at gcc dot gnu dot org
@ 2004-02-16 22:05 ` law at gcc dot gnu dot org
2004-02-16 22:11 ` falk dot hueffner at student dot uni-tuebingen dot de
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: law at gcc dot gnu dot org @ 2004-02-16 22:05 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From law at gcc dot gnu dot org 2004-02-16 22:05 -------
Totally eliminating local1 is for real world code a waste of time -- what would be
the point in having the static variable if it was always set before it was used.
While it would be possible to detect that local1 is 100% totally useless, it's
simply not work the programming effort or compile-time cost.
Now it certainly is worth the cost to eliminate the clearly dead "local1 = 0"
statement as well as the "local2 += c" statement, which is precisely what the
DSE code I checked in earlier today does.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13799
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug optimization/13799] [tree-ssa] consecutive stores to static vars not removed
2004-01-21 20:32 [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed dann at godzilla dot ics dot uci dot edu
2004-01-21 21:46 ` [Bug optimization/13799] " pinskia at gcc dot gnu dot org
2004-02-16 22:05 ` law at gcc dot gnu dot org
@ 2004-02-16 22:11 ` falk dot hueffner at student dot uni-tuebingen dot de
2005-04-17 23:52 ` [Bug rtl-optimization/13799] " pinskia at gcc dot gnu dot org
2005-04-17 23:52 ` [Bug tree-optimization/13799] " pinskia at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: falk dot hueffner at student dot uni-tuebingen dot de @ 2004-02-16 22:11 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From falk dot hueffner at student dot uni-tuebingen dot de 2004-02-16 22:11 -------
Subject: Re: [tree-ssa] consecutive stores to static vars not removed
"law at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> writes:
> Totally eliminating local1 is for real world code a waste of time --
> what would be the point in having the static variable if it was
> always set before it was used.
This occurs a lot in the output of f2c or similar tools.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13799
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug rtl-optimization/13799] [tree-ssa] consecutive stores to static vars not removed
2004-01-21 20:32 [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed dann at godzilla dot ics dot uci dot edu
` (2 preceding siblings ...)
2004-02-16 22:11 ` falk dot hueffner at student dot uni-tuebingen dot de
@ 2005-04-17 23:52 ` pinskia at gcc dot gnu dot org
2005-04-17 23:52 ` [Bug tree-optimization/13799] " pinskia at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-04-17 23:52 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-04-17 23:51 -------
Actually DSE did not fix this and there is a reason, the tree DSE does not understand V_MUST_DEF.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |REOPENED
Resolution|FIXED |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13799
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/13799] [tree-ssa] consecutive stores to static vars not removed
2004-01-21 20:32 [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed dann at godzilla dot ics dot uci dot edu
` (3 preceding siblings ...)
2005-04-17 23:52 ` [Bug rtl-optimization/13799] " pinskia at gcc dot gnu dot org
@ 2005-04-17 23:52 ` pinskia at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-04-17 23:52 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-04-17 23:52 -------
But that makes it a dup of bug 18880.
*** This bug has been marked as a duplicate of 18880 ***
--
What |Removed |Added
----------------------------------------------------------------------------
Status|REOPENED |RESOLVED
Component|rtl-optimization |tree-optimization
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13799
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2005-04-17 23:52 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-01-21 20:32 [Bug optimization/13799] New: [tree-ssa] consecutive stores to static vars not removed dann at godzilla dot ics dot uci dot edu
2004-01-21 21:46 ` [Bug optimization/13799] " pinskia at gcc dot gnu dot org
2004-02-16 22:05 ` law at gcc dot gnu dot org
2004-02-16 22:11 ` falk dot hueffner at student dot uni-tuebingen dot de
2005-04-17 23:52 ` [Bug rtl-optimization/13799] " pinskia at gcc dot gnu dot org
2005-04-17 23:52 ` [Bug tree-optimization/13799] " 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).