Quoting Lennart Augustsson,

> > > This looks very suspicious to me. The symbols `_end' and `_edata' are not
> > > known to the assembler, so doing arithmetic on them is pretty bogus.
> > 
> > They're both link-time constants, so it *should* work..
> Only if you can convey the information to the linker so it can
> perform the arithmetic.  I know the HP object format allows this,
> last I looked our old a.out format couldn't.

Yep, it was bogus:

0xf8100169 <try586+65>: movl   $0x0,%ecx
0xf810016e <try586+70>: xorl   %eax,%eax
0xf8100170 <try586+72>: cld    
0xf8100171 <try586+73>: repz stosl %eax,%es:(%edi)

I checked in a fix.

- Frank