On Thu, Apr 13, 2006 at 01:29:13PM +0200, Paolo Bonzini wrote:
>
> What combine is doing is to expand compound operations such as
> zero_extract, simplifying them, and try to make new compound operations.
> Therefore you should first try to understand what's causing combine to
> miss the simpl
I think it is simply because combine.c doesn't have any code to simplify this kind of expression.
In theory it should have...
However, if you add these simplifications to simplify-rtx.c, it will
be picked up by combine.
There is a lot of simplification code in combine.c too. Should I
On Thu, 13 Apr 2006 13:29:13 +0200, Paolo Bonzini wrote
> > Also, is there a function for simplifying a zero_extract?
>
> What combine is doing is to expand compound operations such as
> zero_extract, simplifying them, and try to make new compound
> operations. Therefore you should first try t
Also, is there a function for simplifying a zero_extract?
What combine is doing is to expand compound operations such as
zero_extract, simplifying them, and try to make new compound operations.
Therefore you should first try to understand what's causing combine to
miss the simplification.
Combine is trying to find this instruction (when compiling _popcountsi2 from
libgcc2.c for my i8086 experiment):
(set (subreg:QI (reg:HI 30) 0)
(mem/s/u:QI (plus:HI (subreg:HI (zero_extract:SI (subreg:HI (reg/v:SI 22 [
x ]) 0)
(const_int 8 [0x8])
(const
