Re: [dj@delorie.com: Results for 4.4.0 20081106 (experimental) [trunk revision 141636] (GCC) testsuite on m32c-unknown-elf]

[Martin Jambor <mjambor at suse dot cz>]

Hi,

On Thu, Nov 06, 2008 at 04:01:13PM -0500, DJ Delorie wrote:
> 
> This new failure seems to have been caused by r141613:
> 
> +2008-11-05  Martin Jambor  <mjambor@suse.cz>
> +
> +       PR middle-end/37861
> +       * tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Don't turn
> +       pointer arithmetics into array_ref if the array is accessed
> +       through an indirect_ref.
> +
> 
> The m32c-elf target is notoriously picky about getting pointer math
> "right" (pointers are 24 bits, not 16 or 32), anyone fiddling with
> pointer/array addressing stuff should probably test it to see if it
> breaks anything.

I only inhibited one particular fwprop action if one particular
condition is met.  I was slightly afraid of some generated code quality
regressions but it should not have really broken anything.

> Martin, can you see if you can reproduce this, and verify whether your
> change broke it or not?  Or if it's something in m32c that your change
> expects to be configured differently?

My knowledge of backend and RTL  in general is very limited and I have
no clue what m32c-elf architecture is and don't seem to have access to
any such system.

>From the logs I see  that the testsuite probably uses a cross-compiled
gcc?  How do  you configure gcc to  get such a beats?  If  I manage to
reproduce it, I can have a look at what differences in the IR I caused
and where that breaks but that  all depends on how much my limited RTL
knowledge allows me to find out...

Martin