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References: <bug-38985-7849@http.gcc.gnu.org/bugzilla/>
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From: Andrew Thomas Pinski <pinskia@gmail.com>
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Subject: Re: [Bug tree-optimization/38985]  New: [4.2/4.3/4.4 Regression] missing constraints for pointers accessed directly via their address
Date: Tue, 27 Jan 2009 11:27:00 -0000
Cc: "gcc-bugs@gcc.gnu.org" <gcc-bugs@gcc.gnu.org>
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Sent from my iPhone

On Jan 27, 2009, at 3:15 AM, "bonzini at gnu dot org" <gcc-bugzilla@gcc.gnu.org 
 > wrote:

> This testcase fails:
>
> /* { dg-do compile } */
> /* { dg-options "-O2 -fdump-tree-optimized" } */
>
> int f(int *p)
> {
>  int a = *p;
>  int *q = (int *)0xDEADBEE0;
>  *q = 5;
>  return *p == a;
> }
>
> /* { dg-final { scan-tree-dump-times " = \\\*p" 2 "optimized" } } */
> /* { dg-final { scan-tree-dump-not "return 1" "optimized" } } */
> /* { dg-final { cleanup-tree-dump "optimized" } } */
>
>
> Unlike PR38984 it does not require -fno-delete-null-pointer-checks.

Volatile addresses also don't have vops on them.  As I mentioned in  
the other bug.  So this is also a bug for volatiles.

>
>
>
> -- 
>           Summary: [4.2/4.3/4.4 Regression] missing constraints for
>                    pointers accessed directly via their address
>           Product: gcc
>           Version: 4.4.0
>            Status: UNCONFIRMED
>          Keywords: wrong-code
>          Severity: normal
>          Priority: P3
>         Component: tree-optimization
>        AssignedTo: unassigned at gcc dot gnu dot org
>        ReportedBy: bonzini at gnu dot org
> OtherBugsDependingO 38984
>             nThis:
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38985
>