Denis Chertykov wrote:
> 2011/6/27 Georg-Johann Lay:
>> Denis Chertykov wrote:

>>> The main problem for me is that the new addressing mode produce a
>>> worse code in many tests.
>> You have an example source?
> 
> In attachment.
> 
> Denis.

Hi Denis.

I had a look at the sources you sent.

sort.c:
=======

There is some difference because of register allocation, but the new
code does not look awfully bad, just a bit different because of
different register allocation that might need some more bytes.

The difference is *not* because of deny fake X addressing, it's
because of the new avr_hard_regno_mode_ok implementation to fix
PR46779.  When I add


  if (GET_MODE_SIZE (mode) == 1)
     return 1;

+     if (SImode == mode && regno == 28)
+       return 0;

   return regno % 2 == 0;

to that function, the difference in code disappears.

pr.c:
=====

I get the following sizes with pr-0 the original compile and pr qith
my patch:

>avr-size pr-0.o
   text    data     bss     dec     hex filename
   2824      24       0    2848     b20 pr-0.o
>avr-size pr.o
   text    data     bss     dec     hex filename
   2564      24       0    2588     a1c pr.o

So the size actually decreased significantly.  Avoiding SI in
avr_hard_regno_mode_ok like above does not change code size.

============

Note that I did *not* use the version from the git repository; I could
not get reasonable code out of it (even after some fixes).  Hundreds
of testsuite crashes...

I used the initial patch that I posted; I attached it again for
reference. Note that LEGITIMIZE_RELOAD_ADDRESS is still not
implemented there.

============

Did you decide about the fix for PR46779?

http://gcc.gnu.org/ml/gcc-patches/2011-06/msg00810.html

Is it ok to commit?

I think fix PR46779 and fix fake X addresses (PR46278) should be
separate patches and not intermixed.

Johann