[PATCH GCC][01/13]Introduce internal function IFN_LOOP_DIST_ALIAS

[Richard Biener]

On Fri, Jun 23, 2017 at 12:10 PM, Bin.Cheng <amker.cheng@gmail.com> wrote:
> On Mon, Jun 12, 2017 at 6:02 PM, Bin Cheng <Bin.Cheng@arm.com> wrote:
>> Hi,
>> I was asked by upstream to split the loop distribution patch into small ones.
>> It is hard because data structure and algorithm are closely coupled together.
>> Anyway, this is the patch series with smaller patches.  Basically I tried to
>> separate data structure and bug-fix changes apart with one as the main patch.
>> Note I only made necessary code refactoring in order to separate patch, apart
>> from that, there is no change against the last version.
>>
>> This is the first patch introducing new internal function IFN_LOOP_DIST_ALIAS.
>> GCC will distribute loops under condition of this function call.
>>
>> Bootstrap and test on x86_64 and AArch64.  Is it OK?
> Hi,
> I need to update this patch fixing an issue in
> vect_loop_dist_alias_call.  The previous patch fails to find some
> IFN_LOOP_DIST_ALIAS calls.
>
> Bootstrap and test in series.  Is it OK?

So I wonder if we really need to track ldist_alias_id or if we can do sth
more "general", like tracking a copy_of or origin and then directly
go to nearest_common_dominator (loop->header, copy_of->header)
to find the controlling condition?

That said "ldist_alias_id" is a bit too narrow of purpose to "waste"
an int inside struct loop?  I'd set copy_of/origi in loop_version for example.
'origin' would probably be better given the ldist cases aren't really
full "copies".

fold_loop_dist_alias_call should re-use / rename fold_loop_vectorized_call
by just passing folded_value to it.

Richard.

> Thanks,
> bin
>>
>> Thanks,
>> bin
>> 2017-06-07  Bin Cheng  <bin.cheng@arm.com>
>>
>>         * cfgloop.h (struct loop): New field ldist_alias_id.
>>         * cfgloopmanip.c (lv_adjust_loop_entry_edge): Comment change.
>>         * internal-fn.c (expand_LOOP_DIST_ALIAS): New function.
>>         * internal-fn.def (LOOP_DIST_ALIAS): New.
>>         * tree-vectorizer.c (vect_loop_dist_alias_call): New function.
>>         (fold_loop_dist_alias_call): New function.
>>         (vectorize_loops): Fold IFN_LOOP_DIST_ALIAS call depending on
>>         successful vectorization or not.