[patch RFC] SH: Use FRAME_GROWS_DOWNWARD

[Joern RENNECKE]

Kaz Kojima wrote:

>    
>
>There is one regression for sh-elf/-m4 and sh-elf/-m4/-ml
>
>  gcc.c-torture/execute/stdarg-2.c execution,  -O2
>
>and one regression for sh-elf and sh-elf/-ml:
>
>  gcc.dg/builtin-apply4.c execution test
>
>though it seems that both tests passed on the unpatched compiler
>accidentally.  With the patched compiler, stdarg-2.c fails
>with sh-elf/-m4 -O2 at the last part of the various tests and
>the reduced testcase
>  
>
Well, now we have established that this is due to a bug in
nonoverlapping_component_refs_p, and that bug is not latent
either, just expressing itself in a different set of cases (as can be
expected by things that depend on the scheduler), so your patch is
OK to check into mainline and the sh-elf-4_1-branch.

>
>with -O2 and gets rid of the failure by luck.
>
>BTW, it's curious that the patched compiler can't optimize
>the corresponding code at -O2.
>
I wouldn't worry to much that the optimization isn't good when the code
is already incorrect.  A more interesting question would be, is the code
comparable with / without your patch
when the untyped_call pattern is made unconditional?