[Bug c++/13312] New: C++ produces stack frame damaging code for Coldfire

[Bug c++/13312] New: C++ produces stack frame damaging code for Coldfire

[Steve at Zook dot com]

Under unclear circumstances, some functions cause code to copy function 
parameters to local area of stack frame. Parameters are copied at declared size 
(unsigned short gets 2 bytes). If parameters are modified in function body, 
emitted code may use a long (4 byte) mode directly to the copied parameter in 
the local stack frame. I have an example from a fragment of the lwIP TCP/IP 
source that causes the problem. An unsigned short parameter was copied to -2(%
a6) and then later in the function an add.l %d1,-2(%a6) was emitted to perform 
a ++ operation on the parameter. This blows %a6 when the function returns and 
crashes the code. This particular instance only occurs when -O2 is used and 
only on Coldfire targets. On other m68k family processors, an add.w %d1,-2(%a6) 
is generated instead which works OK. With lower optimization levels, the code 
loads the value into a register, modifies it, and stores it with a move.w %d1,-2
(%a6). It is possible that this bug relates to bug #8309. I have a file 
tcpout2.ii (which I can provide) that demonstrates the problem. My host and 
build system is Cygwin under Win 2000. My command line is: m68k-elf-gcc -m5200 -
O2 -S tcpout2.ii

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           Summary: C++ produces stack frame damaging code for Coldfire
           Product: gcc
           Version: 3.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Steve at Zook dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-cygwin
  GCC host triplet: i686-pc-cygwin
GCC target triplet: m68k-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug c++/13312] C++ produces stack frame damaging code for Coldfire

[Steve at Zook dot com]

------- Additional Comments From Steve at Zook dot com  2003-12-05 06:34 -------
Created an attachment (id=5283)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=5283&action=view)
A C++ preprocessed source file to demonstrate the bug


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] C++ produces stack frame damaging code for Coldfire

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c++                         |target
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[dhazeghi at yahoo dot com]

------- Additional Comments From dhazeghi at yahoo dot com  2004-01-18 17:54 -------
Bernardo, you frequently build for this target. Would you mind commenting on
this report? Thanks.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bernie at develer dot com
            Summary|C++ produces stack frame    |[m68k] C++ produces stack
                   |damaging code for Coldfire  |frame damaging code for
                   |                            |Coldfire


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[bernie at develer dot com]

------- Additional Comments From bernie at develer dot com  2004-01-19 05:05 -------
I've tried to reproduce this problem with:

 - GCC 3.4 (20040114) + Andreas cc0 patch
 - GCC 3.3.3 (20031222) + my ColdFire/uClinux patch set

In both cases, the generated code seems to be correct, assuming
I'm looking at the same variable:

GCC 3.4:
    move.w %d0,-2(%a6)
    [...]
    clr.l %d0
    move.w -2(%a6),%d0
    add.l %d0,88(%a5)
    move.w 94(%a5),%d0

GCC 3.3.3:
    move.w %d0,-6(%a6)
    [...]
    clr.l %d0
    move.w -6(%a6),%d0
    add.l %d0,88(%a4)
    move.w 94(%a4),%d0

Please test with the latest 3_3-branch snapshot.  If you
still see the problem, try applying all these patches in
the given order:

http://www.develer.com/uclinux/uclinux-tools-20031230/gcc-3.3.2-coldfire-targets.patch
http://www.develer.com/uclinux/uclinux-tools-20031230/gcc-3.3.2-coldfire-frame.patch
http://www.develer.com/uclinux/uclinux-tools-20031230/gcc-3.3.2-uclinux-idshlib.patch
http://www.develer.com/uclinux/uclinux-tools-20031230/gcc-3.3.2-uclinux-thunk.patch
http://www.develer.com/uclinux/uclinux-tools-20031230/gcc-3.3.2-uclinux-specs.patch
http://www.develer.com/uclinux/uclinux-tools-20031230/gcc-3.3.2-coldfire-omitfrmptr.patch

The uClinux patches are not relevant to you, but you need
them in order to apply dependent ColdFire patches.

If any of these patches fixes the problem for you, I'll prepare
a standalone version that applies to 3_3-branch and submit it
for this PR.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[dhazeghi at yahoo dot com]

------- Additional Comments From dhazeghi at yahoo dot com  2004-01-21 17:00 -------
Stepehen, would it be possible for you to check 3.3 branch with the patches Bernie mentioned to 
see if this is still present? Thanks.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[Steve at Zook dot com]

------- Additional Comments From Steve at Zook dot com  2004-01-24 07:08 -------
gcc-3.3-20040119 both with and without Bernardo's patches produces the bug. I 
shall try gcc-3.4-20040121.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[Steve at Zook dot com]

------- Additional Comments From Steve at Zook dot com  2004-01-25 05:01 -------
I built gcc-3.4-20040121. It took a little doing because newlib-1.11.0 (the 
revision I've been using) had a bunch of fatal compile errors that I had to 
fixup (apperently the 3.4 compile is pickier about certain things). The same 
problem persists.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[bernie at develer dot com]

------- Additional Comments From bernie at develer dot com  2004-01-25 09:59 -------
Subject: Re:  [m68k] C++ produces stack frame damaging code
 for Coldfire

Steve at Zook dot com wrote:
> ------- Additional Comments From Steve at Zook dot com  2004-01-25 05:01 -------
> I built gcc-3.4-20040121. It took a little doing because newlib-1.11.0 (the 
> revision I've been using) had a bunch of fatal compile errors that I had to 
> fixup (apperently the 3.4 compile is pickier about certain things). The same 
> problem persists.

Please submit patches to the newlib guys.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[dhazeghi at yahoo dot com]

------- Additional Comments From dhazeghi at yahoo dot com  2004-01-29 03:31 -------
Okay confirmed then. Hopefully somebody'll look at this though...

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-01-29 03:31:33
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[bernie at develer dot com]

------- Additional Comments From bernie at develer dot com  2004-01-29 13:38 -------
I'll hopefully have some time to analyze this regression
along with a few other m68k target bugs after the next week.

Of course, I wouldn't mind if sombody else can fix it
before I do :-)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312

[Bug target/13312] [m68k] C++ produces stack frame damaging code for Coldfire

[bernie at develer dot com]

------- Additional Comments From bernie at develer dot com  2004-06-10 08:03 -------
This patch does indeed fix the bug:

      http://gcc.gnu.org/ml/gcc/2004-05/msg01357.html


2004-05-27  Peter Jakubek  <peter@laseranimation.com>

        * reload.c (find_reloads): force reload for pseudo registers on big
        endian machines.


The generated code to increment the word at -2(a6) with the
patch applied looks like this:

          move.w -2(%a6),%d7
          moveq #1,%d4
          add.l %d4,%d7
          move.w %d7,-2(%a6)
          jbra .L122


*** This bug has been marked as a duplicate of 8309 ***

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13312