[Committed] PR17959: Use paradoxical SUBREGs in emit_group_store

[Eric Botcazou]

> It took a while to figure out what you mean, but yes, there's a
> problem here.

Sorry about the typo!  On the other hand, there was a minimal testcase.

> The subreg_lowpart_offset calls needs to pass (inner, outer) instead of
> (outer, inner).  The problem is that the sense of inner and outer is
> reversed for SUBREGs that access components, vs. PARALLELs that construct
> them. 

Seems reasonable.  Note that you'll end up with (inner, outer) passed to 
subreg_lowpart_offset and (outer, inner) passed to simplify_gen_subreg, so a 
comment explaining the discrepancy would probably be in order.

> Could you check whether that fix works for you on SPARC?

Yup, the failures are gone after the swap (in both places).

-- 
Eric Botcazou