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* [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument
@ 2005-05-27 18:21 evandro at yahoo dot com
2005-05-27 18:23 ` [Bug target/21788] " evandro at yahoo dot com
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: evandro at yahoo dot com @ 2005-05-27 18:21 UTC (permalink / raw)
To: gcc-bugs
Using -O2 or greater, when taking the address of an input argument results in
the wrong code. For example:
int foo (double d)
{
int *p = (int *) &d;
return (*p);
}
With -O2 results in:
foo:
movq -8(%rsp), %eax
ret
With -O1 results in:
foo:
movsd %xmm0, -8(%rsp)
movq -8(%rsp), %eax
ret
--
Summary: [x86_64] Wrong Code When Taking Address of Argument
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: critical
Priority: P2
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: evandro at yahoo dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/21788] [x86_64] Wrong Code When Taking Address of Argument
2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
@ 2005-05-27 18:23 ` evandro at yahoo dot com
2005-05-27 18:24 ` pinskia at gcc dot gnu dot org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: evandro at yahoo dot com @ 2005-05-27 18:23 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From evandro at yahoo dot com 2005-05-27 18:21 -------
Created an attachment (id=8982)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8982&action=view)
Test-case.
If compiled for x86_64 with -O2 or greater, results in bogus code.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/21788] [x86_64] Wrong Code When Taking Address of Argument
2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
2005-05-27 18:23 ` [Bug target/21788] " evandro at yahoo dot com
@ 2005-05-27 18:24 ` pinskia at gcc dot gnu dot org
2005-05-27 18:39 ` pinskia at gcc dot gnu dot org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-05-27 18:24 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-27 18:23 -------
You are violating C aliasing rules, does -fno-strict-aliasing help?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/21788] [x86_64] Wrong Code When Taking Address of Argument
2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
2005-05-27 18:23 ` [Bug target/21788] " evandro at yahoo dot com
2005-05-27 18:24 ` pinskia at gcc dot gnu dot org
@ 2005-05-27 18:39 ` pinskia at gcc dot gnu dot org
2005-05-27 19:20 ` evandro at yahoo dot com
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-05-27 18:39 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-27 18:34 -------
You are violating C aliasing rules.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/21788] [x86_64] Wrong Code When Taking Address of Argument
2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
` (2 preceding siblings ...)
2005-05-27 18:39 ` pinskia at gcc dot gnu dot org
@ 2005-05-27 19:20 ` evandro at yahoo dot com
2005-06-05 9:22 ` pinskia at gcc dot gnu dot org
2005-06-05 9:23 ` pinskia at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: evandro at yahoo dot com @ 2005-05-27 19:20 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From evandro at yahoo dot com 2005-05-27 18:39 -------
(In reply to comment #2)
The wonders of -Wall...
Yes, -fno-strict-aliasing does help.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/21788] [x86_64] Wrong Code When Taking Address of Argument
2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
` (3 preceding siblings ...)
2005-05-27 19:20 ` evandro at yahoo dot com
@ 2005-06-05 9:22 ` pinskia at gcc dot gnu dot org
2005-06-05 9:23 ` pinskia at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-06-05 9:22 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-05 09:22 -------
Reopening to ...
--
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/21788] [x86_64] Wrong Code When Taking Address of Argument
2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
` (4 preceding siblings ...)
2005-06-05 9:22 ` pinskia at gcc dot gnu dot org
@ 2005-06-05 9:23 ` pinskia at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-06-05 9:23 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-05 09:23 -------
Mark as a dup of bug 21920.
*** This bug has been marked as a duplicate of 21920 ***
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21788
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2005-06-05 9:23 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2005-05-27 18:21 [Bug target/21788] New: [x86_64] Wrong Code When Taking Address of Argument evandro at yahoo dot com
2005-05-27 18:23 ` [Bug target/21788] " evandro at yahoo dot com
2005-05-27 18:24 ` pinskia at gcc dot gnu dot org
2005-05-27 18:39 ` pinskia at gcc dot gnu dot org
2005-05-27 19:20 ` evandro at yahoo dot com
2005-06-05 9:22 ` pinskia at gcc dot gnu dot org
2005-06-05 9:23 ` pinskia at gcc dot gnu dot org
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