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* [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias
@ 2004-01-20 7:35 dann at godzilla dot ics dot uci dot edu
2004-01-20 15:20 ` [Bug optimization/13765] " pinskia at gcc dot gnu dot org
` (8 more replies)
0 siblings, 9 replies; 10+ messages in thread
From: dann at godzilla dot ics dot uci dot edu @ 2004-01-20 7:35 UTC (permalink / raw)
To: gcc-bugs
int foo (int * arr)
{
arr[0] = 1;
arr[1] = 2;
if (arr[0] != 1)
abort ();
if (arr[1] != 2)
abort ();
}
The first if is not optimized away because, presumably, the 2 stores are not
considered not to alias.
The .optimized dump:
foo (arr)
{
<bb 0>:
*arr = 1;
*(arr + 4B) = 2;
if (*arr != 1) goto <L0>; else goto <L1>;
<L0>:;
abort ();
<L1>:;
return;
}
--
Summary: [tree-ssa] stores to different members of the same
array should not alias
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=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
@ 2004-01-20 15:20 ` pinskia at gcc dot gnu dot org
2004-01-21 20:19 ` pinskia at gcc dot gnu dot org
` (7 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-20 15:20 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-01-20 15:20 -------
Confirmed, PTA does not help either.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Keywords| |pessimizes-code
Last reconfirmed|0000-00-00 00:00:00 |2004-01-20 15:20:25
date| |
Summary| [tree-ssa] stores to |[tree-ssa] stores to
|different members of the |different members of the
|same array should not alias |same array should not alias
Target Milestone|--- |tree-ssa
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
2004-01-20 15:20 ` [Bug optimization/13765] " pinskia at gcc dot gnu dot org
@ 2004-01-21 20:19 ` pinskia at gcc dot gnu dot org
2004-05-26 18:21 ` [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same pointer " pinskia at gcc dot gnu dot org
` (6 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-01-21 20:19 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same pointer should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
2004-01-20 15:20 ` [Bug optimization/13765] " pinskia at gcc dot gnu dot org
2004-01-21 20:19 ` pinskia at gcc dot gnu dot org
@ 2004-05-26 18:21 ` pinskia at gcc dot gnu dot org
2004-07-05 18:58 ` giovannibajo at libero dot it
` (5 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-26 18:21 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|3.5.0 |---
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same pointer should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
` (2 preceding siblings ...)
2004-05-26 18:21 ` [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same pointer " pinskia at gcc dot gnu dot org
@ 2004-07-05 18:58 ` giovannibajo at libero dot it
2004-07-12 21:40 ` [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array " dann at godzilla dot ics dot uci dot edu
` (4 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: giovannibajo at libero dot it @ 2004-07-05 18:58 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From giovannibajo at libero dot it 2004-07-05 18:58 -------
As requested.
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |dnovillo at gcc dot gnu dot
|dot org |org
Status|NEW |ASSIGNED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
` (3 preceding siblings ...)
2004-07-05 18:58 ` giovannibajo at libero dot it
@ 2004-07-12 21:40 ` dann at godzilla dot ics dot uci dot edu
2004-07-13 0:08 ` dnovillo at redhat dot com
` (3 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: dann at godzilla dot ics dot uci dot edu @ 2004-07-12 21:40 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dann at godzilla dot ics dot uci dot edu 2004-07-12 21:40 -------
Another testcase for whoever is going to fix this:
struct st
{
int *arr;
int c;
int d;
int fl;
};
void foo (struct st *s, int a, int b, int c, int d)
{
*(s->arr) = a; s->arr++;
*(s->arr) = b; s->arr++;
*(s->arr) = c; s->arr++;
}
void foo2 (struct st *s, int a, int b, int c, int d)
{
int *p = s->arr;
*(p) = a; p++;
*(p) = b; p++;
*(p) = c; p++;
s->arr = p;
}
The 2 functions above are compiled to the same assembly code by gcc-3.4 -O2,
the .vars dump for them should be very similar too. It is not so currently.
--
What |Removed |Added
----------------------------------------------------------------------------
Summary|[tree-ssa] stores to |[tree-ssa] stores to
|different members of the |different members of the
|same pointer should not |same array should not alias
|alias |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
` (4 preceding siblings ...)
2004-07-12 21:40 ` [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array " dann at godzilla dot ics dot uci dot edu
@ 2004-07-13 0:08 ` dnovillo at redhat dot com
2004-10-28 20:31 ` dnovillo at gcc dot gnu dot org
` (2 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: dnovillo at redhat dot com @ 2004-07-13 0:08 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dnovillo at redhat dot com 2004-07-13 00:08 -------
Subject: Re: [tree-ssa] stores to different
members of the same array should not alias
On Mon, 2004-07-12 at 17:40, dann at godzilla dot ics dot uci dot edu
wrote:
> ------- Additional Comments From dann at godzilla dot ics dot uci dot edu 2004-07-12 21:40 -------
> Another testcase for whoever is going to fix this:
>
Thanks. I'll be looking at this after I'm done with the current pass
reorganization.
Diego.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
` (5 preceding siblings ...)
2004-07-13 0:08 ` dnovillo at redhat dot com
@ 2004-10-28 20:31 ` dnovillo at gcc dot gnu dot org
2004-10-28 20:34 ` dnovillo at gcc dot gnu dot org
2004-10-28 21:58 ` dberlin at dberlin dot org
8 siblings, 0 replies; 10+ messages in thread
From: dnovillo at gcc dot gnu dot org @ 2004-10-28 20:31 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|dnovillo 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=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
` (6 preceding siblings ...)
2004-10-28 20:31 ` dnovillo at gcc dot gnu dot org
@ 2004-10-28 20:34 ` dnovillo at gcc dot gnu dot org
2004-10-28 21:58 ` dberlin at dberlin dot org
8 siblings, 0 replies; 10+ messages in thread
From: dnovillo at gcc dot gnu dot org @ 2004-10-28 20:34 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dnovillo at gcc dot gnu dot org 2004-10-28 20:34 -------
Dan, ISTR you saying that the field based stuff would also help with arrays. Or
do we want to implement array-SSA? (I'd rather not, in principle).
*** This bug has been marked as a duplicate of 13761 ***
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |dberlin at gcc dot gnu dot
| |org
Status|NEW |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
` (7 preceding siblings ...)
2004-10-28 20:34 ` dnovillo at gcc dot gnu dot org
@ 2004-10-28 21:58 ` dberlin at dberlin dot org
8 siblings, 0 replies; 10+ messages in thread
From: dberlin at dberlin dot org @ 2004-10-28 21:58 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dberlin at dberlin dot org 2004-10-28 21:57 -------
Subject: Re: [tree-ssa] stores to different
members of the same array should not alias
>
> Dan, ISTR you saying that the field based stuff would also help with arrays.
Yes, i can make it happen on arrays as well (for fixed size arrays).
> Or
> do we want to implement array-SSA? (I'd rather not, in principle).
I'd rather not either.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13765
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2004-10-28 21:57 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2004-01-20 7:35 [Bug optimization/13765] New: [tree-ssa] stores to different members of the same array should not alias dann at godzilla dot ics dot uci dot edu
2004-01-20 15:20 ` [Bug optimization/13765] " pinskia at gcc dot gnu dot org
2004-01-21 20:19 ` pinskia at gcc dot gnu dot org
2004-05-26 18:21 ` [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same pointer " pinskia at gcc dot gnu dot org
2004-07-05 18:58 ` giovannibajo at libero dot it
2004-07-12 21:40 ` [Bug tree-optimization/13765] [tree-ssa] stores to different members of the same array " dann at godzilla dot ics dot uci dot edu
2004-07-13 0:08 ` dnovillo at redhat dot com
2004-10-28 20:31 ` dnovillo at gcc dot gnu dot org
2004-10-28 20:34 ` dnovillo at gcc dot gnu dot org
2004-10-28 21:58 ` dberlin at dberlin dot org
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