[Bug target/67305] [6 Regression] gcc.c-torture/compile/20121027-1.c ICE

["jiwang at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67305

--- Comment #7 from Jiong Wang <jiwang at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #6)
> The predicate here is "neon_permissive_struct_operand", and indeed
> it is _very_ permissive ;-)
> 
> This goes through neon_vector_mem_operand(op, 2, false) which immediately
> says "ok!" because there is a frame pointer buried somewhere deep in
> that huge expression.  It looks like the "return !strict;" should read
> "if (strict) return false;".

agree. these blocks of code looks wrong to me.

my understanding is virtual register elimination may cause the const_offset
changed from out of range to within range, so we normally allow any
const_offset if it's used with elim register like (plus elim_reg, const_offset)
if strict_p == false.

so here we should only allow eliminable registers if it's used together with a
constant to form something like (plus elim_reg, const_offset), while we are
allowing any rtx format when strict_p == false.

And Richard, what's your opinion on the "right shift" back to "signed divide"
issue at tree level?