Re: [PATCH,RFC] Do not assign stack slots to ssa names

[Richard Henderson <rth at redhat dot com>]

Andrey Belevantsev wrote:
> Hi,
>
> When processing stack vars partitions for alias export patch, I have
> noticed that sometimes we get SSA_NAMEs being allocated on stack, e.g.
> V2SF vectors.  Richard suggested the attached patch to fix it.  The
> patch is bootstrapped and tested (Ada enabled) on x86-64.  The only
> failing test is stack protector test ssp-2.c, in which an array and a
> loop counter get allocated on stack in a different order and thus
> instead of overflowing the array the test overflows the loop counter and
> hangs.  So I've also fixed the test.
>
> Michael, what do you think of the patch?
> Andrey
>
>
> 2009-06-10  Richard Guenther  <rguenther@suse.de>
> 	    Andrey Belevantsev  <abel@ispras.ru>
>
> 	* cfgexpand.c (expand_one_var): Do not call add_stack_var when original
> variable is an SSA name.

This doesn't make any sense.  AFAICT, you're still allocating stack
space for the variable, just at a different place.