[Bug c++/29141] New: static constructors beyond 64k fail

[Bug c++/29141] New: static constructors beyond 64k fail

[joerg dot diederich at graffiti dot net]

Contruction of global static objects fails while using flash adresses over
0xFFFF, e.g. for bootloader purposes. avr mcu hangs completly before main or
even the called constructor itself.

minimal gcc call: 
avr-c++ -c -mmcu=at90can128 -I. -I. -g -O0 -Wall -Wextra -Wshadow
-Wpointer-arith -Wcast-align -Wsign-compare -Waggregate-return -Wunused
 -fno-exceptions  a_test.cpp -o a_test.o

linked with the following options
-Wl,-Map=a_test.map,--cref,--section-start=.text=0x1F000

short example code in attachment.


-- 
           Summary: static constructors beyond 64k fail
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: joerg dot diederich at graffiti dot net
  GCC host triplet: Linux 2.6.16-1.2111_FC4 i686 athlon i386 GNU/Linux
GCC target triplet: avr


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug c++/29141] static constructors beyond 64k fail

[joerg dot diederich at graffiti dot net]

------- Comment #1 from joerg dot diederich at graffiti dot net  2006-09-19 13:28 -------
Created an attachment (id=12297)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12297&action=view)
example source file


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug c++/29141] static constructors beyond 64k fail

[joerg dot diederich at graffiti dot net]

------- Comment #2 from joerg dot diederich at graffiti dot net  2006-09-19 13:36 -------
thanks to joerg wunsch, additional information is already available.

#ifdef L_ctors
        .section .init6,"ax",@progbits
        .global __do_global_ctors
__do_global_ctors:
        ldi     r17, hi8(__ctors_start)
        ldi     r28, lo8(__ctors_end)
        ldi     r29, hi8(__ctors_end)
        rjmp    .do_global_ctors_start
.do_global_ctors_loop:
        sbiw    r28, 2
        mov_h   r31, r29
        mov_l   r30, r28
        XCALL   __tablejump__
.do_global_ctors_start:
        cpi     r28, lo8(__ctors_start)
        cpc     r29, r17
        brne    .do_global_ctors_loop
#endif /* L_ctors */

using r28/r29 only works for data <64k. r30/r31 are filled with wrong data in
return, in detail 64k less than intended.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug target/29141] static constructors beyond 64k fail

[pete at vavaroutsos dot com]

------- Comment #3 from pete at vavaroutsos dot com  2007-02-02 22:19 -------
I too have ran into this problem. The code in __tablejump__ that calls the
constructors is using LPM instructions instead of ELPM, so the value in the
RAMPZ register is being ignored. Thus a bad pointer to the constructor is
fetched.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug target/29141] static constructors beyond 64k fail

[eric dot weddington at atmel dot com]

------- Comment #4 from eric dot weddington at atmel dot com  2008-10-30 16:03 -------
See also WinAVR bug #2209796 on SourceForge:
https://sourceforge.net/tracker/?func=detail&atid=520074&aid=2209796&group_id=68108


-- 

eric dot weddington at atmel dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-10-30 16:03:06
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug target/29141] static constructors beyond 64k fail

[aesok at gcc dot gnu dot org]

------- Comment #5 from aesok at gcc dot gnu dot org  2009-01-12 20:42 -------
Subject: Bug 29141

Author: aesok
Date: Mon Jan 12 20:41:57 2009
New Revision: 143306

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143306
Log:
        PR target/29141
        * config/avr/t-avr (LIB1ASMFUNCS): Add _tablejump_elpm.
        * config/avr/libgcc.S (__do_global_ctors, __do_global_dtors): Add
        variant for devices with 3-byte PC.
        (__tablejump_elpm__) : New.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/avr/libgcc.S
    trunk/gcc/config/avr/t-avr


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug target/29141] static constructors beyond 64k fail

[aesok at gcc dot gnu dot org]

------- Comment #6 from aesok at gcc dot gnu dot org  2009-01-28 17:53 -------
Fixed.


-- 

aesok at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

[Bug target/29141] static constructors beyond 64k fail

[gcc@d-silva.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

Alastair D'Silva <gcc@d-silva.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gcc@d-silva.org

--- Comment #8 from Alastair D'Silva <gcc@d-silva.org> 2010-11-29 21:39:37 UTC ---
Michael,

I agree. I authored the other patch, but did not have enough knowledge of GCC
for a proper solution. The patch offered in bug 45263 was a workaround based on
what I could observe.

Could you please offer a patch? I can test it and add it to MHV AVR Tools.

[Bug target/29141] static constructors beyond 64k fail

[mschulze at ivs dot cs.ovgu.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29141

Michael Schulze <mschulze at ivs dot cs.ovgu.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mschulze at ivs dot
                   |                            |cs.ovgu.de

--- Comment #7 from Michael Schulze <mschulze at ivs dot cs.ovgu.de> 2010-11-26 19:21:00 UTC ---
In my opinion this bug is still pending and not fixed. The proposed fix uses
register r20 but this could be clobbered by constructor that are called,
leading to destructing the exit condition of the __do_global_ctors loop. In new
version of gcc (see bug 45263 but still not confirmed) this is weakly fixed by
pushing and poping r20 around the constructor call.  

I would suggest using a register between r2-r17 instead of r20. According to
the compiler abi this should be a register that the called routine has to save
if it needs to use it.