Re: [PATCH GCC][4/6]Relax minimal segment length of DR_B for merging alias check

[Richard Biener <richard.guenther@gmail.com>]

On Tue, May 30, 2017 at 5:29 PM, Bin.Cheng <amker.cheng@gmail.com> wrote:
> On Tue, May 30, 2017 at 12:27 PM, Richard Biener
> <richard.guenther@gmail.com> wrote:
>> On Thu, May 25, 2017 at 5:16 PM, Bin.Cheng <amker.cheng@gmail.com> wrote:
>>> On Tue, May 23, 2017 at 5:23 PM, Bin Cheng <Bin.Cheng@arm.com> wrote:
>>>> Hi,
>>>> As commented in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80815#c1,
>>>> We can relax minimal segment length of DR_B for merging.  With this change,
>>>> the new test can be improved to only one alias check.  Note the
>>>> condition is still accurate after this patch, it won't introduce false
>>>> alias.
>>>> Bootstrap and test on x86_64 and AArch64, is it OK?
>>> Updated patch wrto change of previous patch.
>>>
>>> Bootstrap and test on x86_64 and AArch64.
>>
>> Please omit unnecessary braces.  Ok with that change.
>>
>> Note that
>>
>>           if (tree_fits_uhwi_p (dr_b1->seg_len))
>>             {
>>               min_seg_len_b = dr_b1->seg_len;
>>               if (tree_int_cst_sign_bit (dr_b1->seg_len))
>>                 min_seg_len_b = wi::neg (min_seg_len_b);
>>
>> the tree_fits_uhwi_p check is somewhat bogus now that min_seg_len_b is
>> a wide-int.
>> It should probably be changed to TREE_CODE (dr_b1->seg_len) == INTEGER_CST
>> which also means  that
>>
>>               min_seg_len_b = wi::abs (dr_b1->seg_len);
>>
>> should work.
> Thanks for reviewing.  Here is updated patch.  Bootstrap and test on
> x86_64.  Is it OK?

Ok.

Richard.

> Thanks,
> bin
>>
>> Richard.
>>
>>
>>> Thanks,
>>> bin
>>>>
>>>> 2017-05-22  Bin Cheng  <bin.cheng@arm.com>
>>>>
>>>>         * tree-data-ref.c (prune_runtime_alias_test_list): Relax minimal
>>>>         segment length for dr_b.
>>>>
>>>> gcc/testsuite/ChangeLog
>>>> 2017-05-22  Bin Cheng  <bin.cheng@arm.com>
>>>>
>>>>         * gcc.dg/vect/pr80815-3.c: New test.