[Bug c/40366] Array + XOR swap fails

[Bug c/40366] Array + XOR swap fails

[jackie.rosen at hushmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40366

Jackie Rosen <jackie.rosen at hushmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jackie.rosen at hushmail dot com

--- Comment #3 from Jackie Rosen <jackie.rosen at hushmail dot com> ---
*** Bug 260998 has been marked as a duplicate of this bug. ***
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Page where seen: http://volichat.com/adult-chat-rooms
Marked for reference. Resolved as fixed @bugzilla.

[Bug c/40366] Array + XOR swap fails

[timturnerc at yahoo dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40366

Tim Turner <timturnerc at yahoo dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |timturnerc at yahoo dot com

--- Comment #4 from Tim Turner <timturnerc at yahoo dot com> ---
Tentative patch:
...
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
https://www.webb-dev.co.uk/computers/crypto-apps/
index f318a125319..c20c0d7d649 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c http://www.compilatori.com/health/premium-subscription/
@@ -3625,11 +3625,10 @@ create_exception_master_breakpoint (void)
       if (create_exception_master_breakpoint_probe (obj))
        continue;
http://www.acpirateradio.co.uk/health/transportation-security/

-      /* Iterate over separate debug objects and try an _Unwind_DebugHook
-        kind breakpoint.  */
http://www.logoarts.co.uk/health/printers-for-health/
-      for (objfile *sepdebug = obj->separate_debug_objfile;
-          sepdebug != nullptr; sepdebug = sepdebug->separate_debug_objfile)
-       if (create_exception_master_breakpoint_hook (sepdebug))
http://www.slipstone.co.uk/health/sound-systems/
+      /* Iterate over main and separate debug objects and try an
+        _Unwind_DebugHook kind breakpoint.  */
+      for (objfile *debug_objfile : obj->separate_debug_objfiles ())
http://embermanchester.uk/health/social-privacy/
+       if (create_exception_master_breakpoint_hook (debug_objfile))
          break;
Tentative patch: http://connstr.net/health/usb-chargers/
...
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index f318a125319..c20c0d7d649 100644 http://joerg.li/property/latest-suvs/
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -3625,11 +3625,10 @@ create_exception_master_breakpoint (void)
http://www.jopspeech.com/property/slim-pen-2/
       if (create_exception_master_breakpoint_probe (obj))
        continue; http://www.wearelondonmade.com/health/check-ups/

-      /* Iterate over separate debug objects and try an _Unwind_DebugHook
-        kind breakpoint.  */
-      for (objfile *sepdebug = obj->separate_debug_objfile;
https://waytowhatsnext.com/computers/discord-and-steam/
-          sepdebug != nullptr; sepdebug = sepdebug->separate_debug_objfile)
-       if (create_exception_master_breakpoint_hook (sepdebug))
http://www.iu-bloomington.com/computers/real-me-gt2/
+      /* Iterate over main and separate debug objects and try an
+        _Unwind_DebugHook kind breakpoint.  */
https://komiya-dental.com/computers/huawei-technology/
+      for (objfile *debug_objfile : obj->separate_debug_objfiles ())
+       if (create_exception_master_breakpoint_hook (debug_objfile))
          break; http://www-look-4.com/health/winter-sickness/

[Bug c/40366] Array + XOR swap fails

[schwab at linux-m68k dot org]

------- Comment #2 from schwab at linux-m68k dot org  2009-06-07 09:04 -------


*** This bug has been marked as a duplicate of 11751 ***


-- 

schwab at linux-m68k dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40366

[Bug c/40366] Array + XOR swap fails

[pinskia at gmail dot com]

------- Comment #1 from pinskia at gmail dot com  2009-06-07 07:23 -------
Subject: Re:   New: Array + XOR swap fails

Both of these are undefined. Look up about sequence point rules.

Sent from my iPhone

On Jun 7, 2009, at 12:15 AM, "ashutosh dot sharma dot 0204 at gmail  
dot com" <gcc-bugzilla@gcc.gnu.org> wrote:

> Compiler Version:
> gcc (GCC) 4.2.4 (Ubuntu 4.2.4-1ubuntu3)
> Copyright (C) 2007 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There  
> is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR  
> PURPOSE.
>
>
> Sample code:
>
> #include <stdio.h>
>
> int main() {
>        int a[2];
>        a[0]=10;
>        a[1]=20;
>        printf("a[0] = %d a[1] = %d\n", a[0], a[1]);
>        a[0]^=a[1]^=a[0]^=a[1];
>        printf("a[0] = %d a[1] = %d\n", a[0], a[1]);
>        return 0;
> }
>
> gcc test.c -o test -O2
>
> a[0] = 10 a[1] = 20
> a[0] = 20 a[1] = 10
>
> gcc test.c -o test -O0
>
> a[0] = 10 a[1] = 20
> a[0] = 0 a[1] = 10
>
> Bug: When compiled with -O0 swap fails.
> Swap only fails in case of array. Following code works fine with -O0:
>
> #include <stdio.h>
>
> int main() {
>        int a, b;
>        a=10;
>        b=20;
>        printf("a = %d b = %d\n", a, b);
>        a^=b^=a^=b;
>        printf("a = %d b = %d\n", a, b);
>        return 0;
> }
>
>
> -- 
>           Summary: Array + XOR swap fails
>           Product: gcc
>           Version: unknown
>            Status: UNCONFIRMED
>          Severity: major
>          Priority: P3
>         Component: c
>        AssignedTo: unassigned at gcc dot gnu dot org
>        ReportedBy: ashutosh dot sharma dot 0204 at gmail dot com
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40366
>


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40366