Error in INSN_ADDRESSES (INSN_UID (get_last_insn ()))

Error in INSN_ADDRESSES (INSN_UID (get_last_insn ()))

[Marek Michalkiewicz]

Hi,

trying to build --target=avr from CVS today, I got the following error:

../../../cvs/egcs/gcc/libgcc2.c: In function `__cmpdi2':
../../../cvs/egcs/gcc/libgcc2.c:812: virtual array insn_addresses[184]: element
186 out of bounds in avr_output_function_epilogue, at config/avr/avr.c:752
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

The offending code in avr.c:752 is this:

  function_size = (INSN_ADDRESSES (INSN_UID (get_last_insn ()))
                   - INSN_ADDRESSES (INSN_UID (get_insns ())));

The size is only used for statistics (numbers reported as part of comments
in the asm output) so it's no big deal if it has to be disabled, but it
used to work...  Is this a bug in the AVR port (shouldn't calculate the
function size that way, it worked by accident), or a bug elsewhere in GCC?

Thanks,
Marek

Re: Error in INSN_ADDRESSES (INSN_UID (get_last_insn ()))

[Jan Hubicka]

> Hi,
> 
> trying to build --target=avr from CVS today, I got the following error:
> 
> ../../../cvs/egcs/gcc/libgcc2.c: In function `__cmpdi2':
> ../../../cvs/egcs/gcc/libgcc2.c:812: virtual array insn_addresses[184]: element
> 186 out of bounds in avr_output_function_epilogue, at config/avr/avr.c:752
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.
> 
> The offending code in avr.c:752 is this:
> 
>   function_size = (INSN_ADDRESSES (INSN_UID (get_last_insn ()))
>                    - INSN_ADDRESSES (INSN_UID (get_insns ())));
> 
> The size is only used for statistics (numbers reported as part of comments
> in the asm output) so it's no big deal if it has to be disabled, but it
> used to work...  Is this a bug in the AVR port (shouldn't calculate the
> function size that way, it worked by accident), or a bug elsewhere in GCC?

This appears to be side effect of my INSN_STMT change.  I now rebuild
NOTE_BLOCK_BEG/NOTE_BLOCK_END after branch shortening resulting in
unintialized INSN_ADDRESSES.

I've fixed generic code to deal with this, but didn't expected such
tricks in machine dependent bits.
Simplu looking for first/last nonnote insn will solve your problem.
Is this scheme common enought?  If yes, I may think about rebuilding the
scope forest earlier, but this is unfortunate from different point of
view - I don't want to do so when -g is not passed and not doing so
always may cause differences in generated file.

Honza
> 
> Thanks,
> Marek