On Wed, May 18, 2016 at 5:29 PM, Kumar, Venkataramanan
<venkataramanan.ku...@amd.com> wrote:
> Hi Richard,
>
>> -----Original Message-----
>> From: Richard Biener [mailto:richard.guent...@gmail.com]
>> Sent: Tuesday, May 17, 2016 5:40 PM
>> To: Kumar, Venkataramanan <venkataramanan.ku...@amd.com>
>> Cc: gcc-patches@gcc.gnu.org
>> Subject: Re: [Patch V2] Fix SLP PR58135.
>>
>> On Tue, May 17, 2016 at 1:56 PM, Kumar, Venkataramanan
>> <venkataramanan.ku...@amd.com> wrote:
>> > Hi Richard,
>> >
>> > I created the patch by passing -b option to git. Now the patch is more
>> readable.
>> >
>> > As per your suggestion I tried to fix the PR by splitting the SLP store
>> > group at
>> vector boundary after the SLP tree is built.
>> >
>> > Boot strap PASSED on x86_64.
>> > Checked the patch with check_GNU_style.sh.
>> >
>> > The gfortran.dg/pr46519-1.f test now does SLP vectorization. Hence it
>> generated 2 more vzeroupper.
>> > As recommended I adjusted the test case by adding -fno-tree-slp-vectorize
>> to make it as expected after loop vectorization.
>> >
>> > The following tests are now passing.
>> >
>> > ------ Snip-----
>> > Tests that now work, but didn't before:
>> >
>> > gcc.dg/vect/bb-slp-19.c -flto -ffat-lto-objects scan-tree-dump-times
>> > slp2 "basic block vectorized" 1
>> >
>> > gcc.dg/vect/bb-slp-19.c scan-tree-dump-times slp2 "basic block
>> > vectorized" 1
>> >
>> > New tests that PASS:
>> >
>> > gcc.dg/vect/pr58135.c (test for excess errors) gcc.dg/vect/pr58135.c
>> > -flto -ffat-lto-objects (test for excess errors)
>> >
>> > ------ Snip-----
>> >
>> > ChangeLog
>> >
>> > 2016-05-14 Venkataramanan Kumar
>> <venkataramanan.ku...@amd.com>
>> > PR tree-optimization/58135
>> > * tree-vect-slp.c: When group size is not multiple of vector size,
>> > allow splitting of store group at vector boundary.
>> >
>> > Test suite ChangeLog
>> > 2016-05-14 Venkataramanan Kumar
>> <venkataramanan.ku...@amd.com>
>> > * gcc.dg/vect/bb-slp-19.c: Remove XFAIL.
>> > * gcc.dg/vect/pr58135.c: Add new.
>> > * gfortran.dg/pr46519-1.f: Adjust test case.
>> >
>> > The attached patch Ok for trunk?
>>
>>
>> Please avoid the excessive vertical space around the vect_build_slp_tree
>> call.
> Yes fixed in the attached patch.
>>
>> + /* Calculate the unrolling factor. */
>> + unrolling_factor = least_common_multiple
>> + (nunits, group_size) / group_size;
>> ...
>> + else
>> {
>> /* Calculate the unrolling factor based on the smallest type. */
>> if (max_nunits > nunits)
>> - unrolling_factor = least_common_multiple (max_nunits, group_size)
>> - / group_size;
>> + unrolling_factor
>> + = least_common_multiple (max_nunits,
>> + group_size)/group_size;
>>
>> please compute the "correct" unroll factor immediately and move the
>> "unrolling of BB required" error into the if() case by post-poning the
>> nunits <
>> group_size check (and use max_nunits here).
>>
> Yes fixed in the attached patch.
>
>> + if (is_a <bb_vec_info> (vinfo)
>> + && nunits < group_size
>> + && unrolling_factor != 1
>> + && is_a <bb_vec_info> (vinfo))
>> + {
>> + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
>> + "Build SLP failed: store group "
>> + "size not a multiple of the vector size "
>> + "in basic block SLP\n");
>> + /* Fatal mismatch. */
>> + matches[nunits] = false;
>>
>> this is too pessimistic - you want to add the extra 'false' at group_size /
>> max_nunits * max_nunits.
> Yes fixed in attached patch.
>
>>
>> It looks like you leak 'node' in the if () path as well. You need
>>
>> vect_free_slp_tree (node);
>> loads.release ();
>>
>> thus treat it as a failure case.
>
> Yes fixed. I added an else part before scalar_stmts.release call for the case
> when SLP tree is not built. This avoids double freeing.
> Bootstrapped and reg tested on X86_64.
>
> Ok for trunk ?
+ /*Calculate the unrolling factor based on the smallest type. */
+ unrolling_factor
Space after /* missing.
+ unrolling_factor
+ = least_common_multiple (max_nunits, group_size)/group_size;
spaces before/after the '/'
+ if (max_nunits > nunits
+ && unrolling_factor != 1
+ && is_a <bb_vec_info> (vinfo))
{
if (dump_enabled_p ())
- dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
- "Build SLP failed: unrolling required in basic"
- " block SLP\n");
+ dump_printf_loc (MSG_MISSED_OPTIMIZATION,
+ vect_location,
+ "Build SLP failed: unrolling "
+ "required in basic block SLP\n");
vect_free_slp_tree (node);
loads.release ();
return false;
}
+ if (is_a <bb_vec_info> (vinfo)
+ && max_nunits < group_size
+ && unrolling_factor != 1)
please merge these. I think you have a not covered case of max_nunits
== nunits, max_nunits > group_size.
So do
if (unrolling_factor != 1
&& is_a <...>)
{
if (max_nunits >= group_size)
{
first error
}
... signal fatal mismatch instead...
}
else
{
Ok with that change.
Thanks,
Richard.
>>
>> Thanks,
>> Richard.
>>
>> > Regards,
>> > Venkat.
>> >
>
> Regards,
> Venkat.
