Re: [patch] Don't insert pattern statements into the code (was Fix PR tree-optimization/49318)

[Ira Rosen <ira.rosen@linaro.org>]

On 14 June 2011 14:27, Richard Guenther <richard.guenther@gmail.com> wrote:

>>>
>>>   /* Mark the stmts that are involved in the pattern. */
>>> -  gsi_insert_before (&si, pattern_stmt, GSI_SAME_STMT);
>>>   set_vinfo_for_stmt (pattern_stmt,
>>>                      new_stmt_vec_info (pattern_stmt, loop_vinfo, NULL));
>>> +  gimple_set_bb (pattern_stmt, gimple_bb (stmt));
>>>
>>> do you really need this?
>>
>> Yes, there are a lot of uses of gimple_bb (stmt). Otherwise, we'd have
>> to check there that bb exists (or that this is not a pattern stmt) and
>> use the bb of the original statement if not.
>
> I see.  It's not really uglier than the part where you have to special-case
> them when walking use-operands, so ...

I think it is uglier, because there are 42 cases to handle instead of
a single place that you mentioned. (Probably not all the 42 can be
really reached with a pattern stmt, but still it's a lot).

Thanks,
Ira

>
> Still a lot better than when inserting them for real.
>
>>> Otherwise it looks reasonable.  Btw,
>>> we can probably remove the simple DCE done in
>>> slpeel_tree_peel_loop_to_edge (remove_dead_stmts_from_loop)
>>> with this patch.
>>
>> I'll try that.
>
> Thanks,
> Richard.
>
>> Thanks,
>> Ira
>>
>>>
>>> Thanks,
>>> Richard.
>>>
>>>> Thanks,
>>>> Ira
>>>>
>>>> ChangeLog:
>>>>
>>>>     * tree-vect-loop.c (vect_determine_vectorization_factor): Don't
>>>>     remove irrelevant pattern statements.  For irrelevant statements
>>>>     check if it is the last statement of a detected pattern, use
>>>>     corresponding pattern statement instead.
>>>>     (destroy_loop_vec_info): No need to remove pattern statements,
>>>>     only free stmt_vec_info.
>>>>     (vect_transform_loop): For irrelevant statements check if it is
>>>>     the last statement of a detected pattern, use corresponding
>>>>     pattern statement instead.
>>>>     * tree-vect-patterns.c (vect_pattern_recog_1): Don't insert
>>>>     pattern statements.  Set basic block for the new statement.
>>>>     (vect_pattern_recog): Update documentation.
>>>>     * tree-vect-stmts.c (vect_mark_stmts_to_be_vectorized): Scan
>>>>     operands of pattern statements.
>>>>     (vectorizable_call): Fix printing.  In case of a pattern statement
>>>>     use the lhs of the original statement when creating a dummy
>>>>     statement to replace the original call.
>>>>     (vect_analyze_stmt): For irrelevant statements check if it is
>>>>     the last statement of a detected pattern, use corresponding
>>>>     pattern statement instead.
>>>>     * tree-vect-slp.c (vect_schedule_slp_instance): For pattern
>>>>     statements use gsi of the original statement.
>>>>
>>>
>>
>