On Wed, Feb 10, 2016 at 11:26 AM, Yuri Rumyantsev <ysrum...@gmail.com> wrote:
> Thanks Richard for your comments.
> I changes algorithm to remove dead scalar statements as you proposed.
>
> Bootstrap and regression testing did not show any new failures on x86-64.
> Is it OK for trunk?
Ok.
Thanks,
Richard.
> Changelog:
> 2016-02-10 Yuri Rumyantsev <ysrum...@gmail.com>
>
> PR tree-optimization/69652
> * tree-vect-loop.c (optimize_mask_stores): Move declaration of STMT1
> to nested loop, did source re-formatting, skip debug statements,
> add check on statement with volatile operand, remove dead scalar
> statements.
>
> gcc/testsuite/ChangeLog:
> * gcc.dg/torture/pr69652.c: New test.
>
>
> 2016-02-09 15:33 GMT+03:00 Richard Biener <richard.guent...@gmail.com>:
>> On Fri, Feb 5, 2016 at 3:54 PM, Yuri Rumyantsev <ysrum...@gmail.com> wrote:
>>> Hi All,
>>>
>>> Here is updated patch - I came back to move call statements also since
>>> masked loads are presented by internal call. I also assume that for
>>> the following simple loop
>>> for (i = 0; i < n; i++)
>>> if (b1[i])
>>> a1[i] = sqrtf(a2[i] * a2[i] + a3[i] * a3[i]);
>>> motion must be done for all vector statements in semi-hammock including
>>> SQRT.
>>>
>>> Bootstrap and regression testing did not show any new failures.
>>> Is it OK for trunk?
>>
>> The patch is incredibly hard to parse due to the re-indenting. Please
>> consider sending
>> diffs with -b.
>>
>> This issue exposes that you are moving (masked) stores across loads without
>> checking aliasing. In the specific case those loads are dead and thus
>> this is safe
>> but in general I thought we were checking that we are using the same VUSE
>> during the sinking operation.
>>
>> Thus, I'd rather have
>>
>> + /* Check that LHS does not have uses outside of STORE_BB. */
>> + res = true;
>> + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
>> + {
>> + gimple *use_stmt;
>> + use_stmt = USE_STMT (use_p);
>> + if (is_gimple_debug (use_stmt))
>> + continue;
>> + if (gimple_bb (use_stmt) != store_bb)
>> + {
>> + res = false;
>> + break;
>> + }
>> + }
>>
>> also check for the dead code case and DCE those stmts here. Like so:
>>
>> if (has_zero_uses (lhs))
>> {
>> gsi_remove (&gsi_from, true);
>> continue;
>> }
>>
>> before the above loop.
>>
>> Richard.
>>
>>> ChangeLog:
>>>
>>> 2016-02-05 Yuri Rumyantsev <ysrum...@gmail.com>
>>>
>>> PR tree-optimization/69652
>>> * tree-vect-loop.c (optimize_mask_stores): Move declaration of STMT1
>>> to nested loop, introduce new SCALAR_VUSE vector to keep vuse of all
>>> skipped scalar statements, introduce variable LAST_VUSE to keep
>>> vuse of LAST_STORE, add assertion that SCALAR_VUSE is empty in the
>>> begining of current masked store processing, did source re-formatting,
>>> skip parsing of debug gimples, stop processing if a gimple with
>>> volatile operand has been encountered, save scalar statement
>>> with vuse in SCALAR_VUSE, skip processing debug statements in IMM_USE
>>> iterator, change vuse of all saved scalar statements to LAST_VUSE if
>>> it makes sence.
>>>
>>> gcc/testsuite/ChangeLog:
>>> * gcc.dg/torture/pr69652.c: New test.
>>>
>>> 2016-02-04 19:40 GMT+03:00 Jakub Jelinek <ja...@redhat.com>:
>>>> On Thu, Feb 04, 2016 at 05:46:27PM +0300, Yuri Rumyantsev wrote:
>>>>> Here is a patch that cures the issues with non-correct vuse for scalar
>>>>> statements during code motion, i.e. if vuse of scalar statement is
>>>>> vdef of masked store which has been sunk to new basic block, we must
>>>>> fix it up. The patch also fixed almost all remarks pointed out by
>>>>> Jacub.
>>>>>
>>>>> Bootstrapping and regression testing on v86-64 did not show any new
>>>>> failures.
>>>>> Is it OK for trunk?
>>>>>
>>>>> ChangeLog:
>>>>> 2016-02-04 Yuri Rumyantsev <ysrum...@gmail.com>
>>>>>
>>>>> PR tree-optimization/69652
>>>>> * tree-vect-loop.c (optimize_mask_stores): Move declaration of STMT1
>>>>> to nested loop, introduce new SCALAR_VUSE vector to keep vuse of all
>>>>> skipped scalar statements, introduce variable LAST_VUSE that has
>>>>> vuse of LAST_STORE, add assertion that SCALAR_VUSE is empty in the
>>>>> begining of current masked store processing, did source re-formatting,
>>>>> skip parsing of debug gimples, stop processing when call or gimple
>>>>> with volatile operand habe been encountered, save scalar statement
>>>>> with vuse in SCALAR_VUSE, skip processing debug statements in IMM_USE
>>>>> iterator, change vuse of all saved scalar statements to LAST_VUSE if
>>>>> it makes sence.
>>>>>
>>>>> gcc/testsuite/ChangeLog:
>>>>> * gcc.dg/torture/pr69652.c: New test.
>>>>
>>>> Your mailer breaks ChangeLog formatting, so it is hard to check the
>>>> formatting of the ChangeLog entry.
>>>>
>>>> diff --git a/gcc/testsuite/gcc.dg/torture/pr69652.c
>>>> b/gcc/testsuite/gcc.dg/torture/pr69652.c
>>>> new file mode 100644
>>>> index 0000000..91f30cf
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/torture/pr69652.c
>>>> @@ -0,0 +1,14 @@
>>>> +/* { dg-do compile } */
>>>> +/* { dg-options "-O2 -ffast-math -ftree-vectorize " } */
>>>> +/* { dg-additional-options "-mavx" { target { i?86-*-* x86_64-*-* } } } */
>>>> +
>>>> +void fn1(double **matrix, int column, int row, int n)
>>>> +{
>>>> + int k;
>>>> + for (k = 0; k < n; k++)
>>>> + if (matrix[row][k] != matrix[column][k])
>>>> + {
>>>> + matrix[column][k] = -matrix[column][k];
>>>> + matrix[row][k] = matrix[row][k] - matrix[column][k];
>>>> + }
>>>> +}
>>>> \ No newline at end of file
>>>>
>>>> Please make sure the last line of the test is a new-line.
>>>>
>>>> @@ -6971,6 +6972,8 @@ optimize_mask_stores (struct loop *loop)
>>>> gsi_next (&gsi))
>>>> {
>>>> stmt = gsi_stmt (gsi);
>>>> + if (is_gimple_debug (stmt))
>>>> + continue;
>>>> if (is_gimple_call (stmt)
>>>> && gimple_call_internal_p (stmt)
>>>> && gimple_call_internal_fn (stmt) == IFN_MASK_STORE)
>>>>
>>>> This is not needed, you do something only for is_gimple_call,
>>>> which is never true if is_gimple_debug, so the code used to be fine as is.
>>>>
>>>> + /* Skip debug sstatements. */
>>>>
>>>> s/ss/s/
>>>>
>>>> + if (is_gimple_debug (gsi_stmt (gsi)))
>>>> + continue;
>>>> + stmt1 = gsi_stmt (gsi);
>>>> + /* Do not consider writing to memory,volatile and call
>>>>
>>>> Missing space after ,
>>>>
>>>> + /* Skip scalar statements. */
>>>> + if (!VECTOR_TYPE_P (TREE_TYPE (lhs)))
>>>> + {
>>>> + /* If scalar statement has vuse we need to modify it
>>>> + when another masked store will be sunk. */
>>>> + if (gimple_vuse (stmt1))
>>>> + scalar_vuse.safe_push (stmt1);
>>>> continue;
>>>> + }
>>>>
>>>> I don't think it is safe to take for granted that the scalar stmts are all
>>>> going to be DCEd, but I could be wrong.
>>>>
>>>> + /* Check that LHS does not have uses outside of STORE_BB. */
>>>> + res = true;
>>>> + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
>>>> + {
>>>> + gimple *use_stmt;
>>>> + use_stmt = USE_STMT (use_p);
>>>> + if (is_gimple_debug (use_stmt))
>>>> + continue;
>>>>
>>>> Ignoring debug stmts to make decision whether you move or not is
>>>> of course the right thing to do. But IMHO you should remember if
>>>> you saw any is_gimple_debug stmts in some bool var.
>>>>
>>>> + if (gimple_bb (use_stmt) != store_bb)
>>>> + {
>>>> + res = false;
>>>> + break;
>>>> + }
>>>> + }
>>>> + if (!res)
>>>> + break;
>>>>
>>>> - if (gimple_vuse (stmt1)
>>>> - && gimple_vuse (stmt1) != gimple_vuse (last_store))
>>>> - break;
>>>> + if (gimple_vuse (stmt1)
>>>> + && gimple_vuse (stmt1) != gimple_vuse (last_store))
>>>> + break;
>>>>
>>>> + /* Can move STMT1 to STORE_BB. */
>>>> + if (dump_enabled_p ())
>>>> + {
>>>> + dump_printf_loc (MSG_NOTE, vect_location,
>>>> + "Move stmt to created bb\n");
>>>> + dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt1, 0);
>>>> + }
>>>>
>>>> And if yes, invalidate them here, because the move would otherwise
>>>> generate invalid IL.
>>>>
>>>> + gsi_move_before (&gsi_from, &gsi_to);
>>>> + /* Shift GSI_TO for further insertion. */
>>>> + gsi_prev (&gsi_to);
>>>> + }
>>>> + /* Put other masked stores with the same mask to STORE_BB. */
>>>> + if (worklist.is_empty ()
>>>> + || gimple_call_arg (worklist.last (), 2) != mask
>>>> + || worklist.last () != stmt1)
>>>> + break;
>>>> + last = worklist.pop ();
>>>> }
>>>> add_phi_arg (phi, gimple_vuse (last_store), e, UNKNOWN_LOCATION);
>>>> + /* Mask stores motion could crossing scalar statements with vuse
>>>> + which should be corrected. */
>>>>
>>>> s/crossing/cross/
>>>> That said, I'm not really sure if without some verification if such
>>>> reads are really dead it is safe to skip them and update this way.
>>>> Richard?
>>>>
>>>> + last_vuse = gimple_vuse (last_store);
>>>> + while (!scalar_vuse.is_empty ())
>>>> + {
>>>> + stmt = scalar_vuse.pop ();
>>>> + if (gimple_vuse (stmt) != last_vuse)
>>>> + {
>>>> + gimple_set_vuse (stmt, last_vuse);
>>>> + update_stmt (stmt);
>>>> + }
>>>> + }
>>>> }
>>>> }
>>>>
>>>> Jakub
