[patch] Fix var-tracking with dynamic stack realignment on x86

[Eric Botcazou]

> Do you mean something like the attached one?  We don't have guality
> testsuite for ada and I think ada testcases are quite unreadable for most
> people.  Definitely to me.  Plus it is always better to have a single
> file testcase over 5 files.

Sure.  Last time I mentioned the guality testsuite, I was told that its results 
were random.  Thanks for the testcase in any case.

> I guess this might be somewhat related to Alex'
> http://gcc.gnu.org/ml/gcc-patches/2011-02/msg00981.html, but haven't tried
> that patch.  But with tracking addresses as VALUEs var-tracking should
> hopefully figure out that when %ecx as the DRAP register is saved into a
> non-aliased stack location and then (maybe) clobbered during the call
> that the addresses shouldn't use that hard reg afterwards, but need to
> read it from the mem slot.

Interesting, thanks for the pointer.

> Anyway, IMHO the desired outcome is that the 
> parameters will have DW_OP_fbreg {0,4} as their location, so perhaps the
> DRAP register needs to be remapped somehow during adjust_insn.

So you don't care about their location during the prologue?

-- 
Eric Botcazou