On 25 May 2016 at 05:29, Kumar, Venkataramanan
<venkataramanan.ku...@amd.com> wrote:
> Hi Christophe,
>
>> -----Original Message-----
>> From: Christophe Lyon [mailto:christophe.l...@linaro.org]
>> Sent: Tuesday, May 24, 2016 8:45 PM
>> To: Kumar, Venkataramanan <venkataramanan.ku...@amd.com>
>> Cc: Richard Biener <richard.guent...@gmail.com>; gcc-patches@gcc.gnu.org
>> Subject: Re: [Patch V2] Fix SLP PR58135.
>>
>> Hi Venkat,
>>
>>
>> On 23 May 2016 at 11:54, Kumar, Venkataramanan
>> <venkataramanan.ku...@amd.com> wrote:
>> > Hi Richard,
>> >
>> >> -----Original Message-----
>> >> From: Richard Biener [mailto:richard.guent...@gmail.com]
>> >> Sent: Thursday, May 19, 2016 4:08 PM
>> >> To: Kumar, Venkataramanan <venkataramanan.ku...@amd.com>
>> >> Cc: gcc-patches@gcc.gnu.org
>> >> Subject: Re: [Patch V2] Fix SLP PR58135.
>> >>
>> >> 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.
>> >> >
>>
>> This patch is causing regressions on armeb:
>> http://people.linaro.org/~christophe.lyon/cross-
>> validation/gcc/trunk/236591/report-build-info.html
>> The following fortran tests now fail at runtime:
>>
>> gfortran.dg/c_f_pointer_logical.f03 -O3 -fomit-frame-pointer
>> -funroll-loops -fpeel-loops -ftracer -finline-functions execution test
>> gfortran.dg/c_f_pointer_logical.f03 -O3 -g execution test
>> gfortran.dg/intrinsic_pack_1.f90 -O3 -fomit-frame-pointer
>> -funroll-loops -fpeel-loops -ftracer -finline-functions execution test
>> gfortran.dg/intrinsic_pack_1.f90 -O3 -g execution test
>>
>> Can you have a look?
>>
>
> Sure. I will take a look.
>
Thanks, I've filed https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71270
to keep track of this.
Christophe
>> Thanks,
>>
>> Christophe.
>>
>>
>>
>> >> > 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.
>> >
>> > Thank you for the review. I updated and patch and up streamed it to trunk.
>> > Ref: https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=236582
>> >
>> > Regards,
>> > Venkat.
>
> Regards,
> Venkat.
