public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug optimization/13762] New: [tree-ssa] stores to different members of the same array should not alias
@ 2004-01-20 7:12 dann at godzilla dot ics dot uci dot edu
2004-01-20 7:22 ` [Bug optimization/13762] " marcus at jet dot franken dot de
2004-01-20 7:30 ` dann at godzilla dot ics dot uci dot edu
0 siblings, 2 replies; 3+ messages in thread
From: dann at godzilla dot ics dot uci dot edu @ 2004-01-20 7:12 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.
Also strange is that the second store is performed twice.
The .optimized dump:
foo (arr)
{
int * T.1;
<bb 0>:
*arr = 1;
T.1 = arr + 4B;
*T.1 = 2;
if (*arr != 1) goto <L0>; else goto <L1>;
<L0>:;
abort ();
<L1>:;
*T.1 = 2;
abort ();
}
--
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=13762
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug optimization/13762] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:12 [Bug optimization/13762] 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 7:22 ` marcus at jet dot franken dot de
2004-01-20 7:30 ` dann at godzilla dot ics dot uci dot edu
1 sibling, 0 replies; 3+ messages in thread
From: marcus at jet dot franken dot de @ 2004-01-20 7:22 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From marcus at jet dot franken dot de 2004-01-20 07:21 -------
you wanted to write if (a[0] == 2), not a[0]=2 i guess...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13762
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug optimization/13762] [tree-ssa] stores to different members of the same array should not alias
2004-01-20 7:12 [Bug optimization/13762] 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 7:22 ` [Bug optimization/13762] " marcus at jet dot franken dot de
@ 2004-01-20 7:30 ` dann at godzilla dot ics dot uci dot edu
1 sibling, 0 replies; 3+ messages in thread
From: dann at godzilla dot ics dot uci dot edu @ 2004-01-20 7:30 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From dann at godzilla dot ics dot uci dot edu 2004-01-20 07:30 -------
Actually it should have been arr[1] != 2
I'll close this bug and open one with the correct testcase.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13762
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2004-01-20 7:30 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-01-20 7:12 [Bug optimization/13762] 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 7:22 ` [Bug optimization/13762] " marcus at jet dot franken dot de
2004-01-20 7:30 ` dann at godzilla dot ics dot uci dot edu
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).