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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) -- links below jump to the message on this page -- 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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