Re: [PATCH 3/3] Enhance dumps of IVOPTS

["Martin Liška" <mliska@suse.cz>]

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On 05/13/2016 02:11 PM, H.J. Lu wrote:
> On Fri, May 13, 2016 at 3:44 AM, Martin Liška <mliska@suse.cz> wrote:
>> On 05/13/2016 11:43 AM, Bin.Cheng wrote:
>>> On Thu, May 12, 2016 at 5:41 PM, Martin Liška <mliska@suse.cz> wrote:
>>>> On 05/12/2016 03:51 PM, Bin.Cheng wrote:
>>>>> On Thu, May 12, 2016 at 1:13 PM, Martin Liška <mliska@suse.cz> wrote:
>>>>>> On 05/10/2016 03:16 PM, Bin.Cheng wrote:
>>>>>>> Another way is to remove the use of id for struct iv_inv_expr_ent once
>>>>>>> for all.  We can change iv_ca.used_inv_expr and cost_pair.inv_expr_id
>>>>>>> to pointers, and rename iv_inv_expr_ent.id to count and use this to
>>>>>>> record reference number in iv_ca.  This if-statement on dump_file can
>>>>>>> be saved.  Also I think it simplifies current code a bit.  For now,
>>>>>>> there are id <-> struct maps for different structures in IVOPT which
>>>>>>> make it not straightforward.
>>>>>>
>>>>>> Hi.
>>>>>>
>>>>>> I'm sending second version of the patch. I tried to follow your advices, but
>>>>>> because of a iv_inv_expr_ent can simultaneously belong to multiply iv_cas,
>>>>>> putting counter to iv_inv_expr_ent does not works. Instead of that, I've
>>>>>> decided to replace used_inv_expr with a hash_map that contains used inv_exps
>>>>>> and where value of the map is # of usages.
>>>>>>
>>>>>> Further questions:
>>>>>> + iv_inv_expr_ent::id can be now removed as it's used just for purpose of dumps
>>>>>> Group 0:
>>>>>>   cand  cost    scaled  freq    compl.  depends on
>>>>>>   5     2       2.00    1.000
>>>>>>   6     4       4.00    1.001    inv_expr:0
>>>>>>   7     4       4.00    1.001    inv_expr:1
>>>>>>   8     4       4.00    1.001    inv_expr:2
>>>>>>
>>>>>> That can be replaced with print_generic_expr, but I think using ids makes the dump
>>>>>> output more clear.
>>>>> I am okay with keeping id.  Could you please dump all inv_exprs in a
>>>>> single section like
>>>>> <Invariant Exprs>:
>>>>> inv_expr 0: print_generic_expr
>>>>> inv_expr 1: ...
>>>>>
>>>>> Then only dump the id afterwards?
>>>>>
>>>>
>>>> Sure, it would be definitely better:
>>>>
>>>> The new dump format looks:
>>>>
>>>> <Invariant Expressions>:
>>>> inv_expr 0:     sudoku_351(D) + (sizetype) S.833_774 * 4
>>>> inv_expr 1:     sudoku_351(D) + ((sizetype) S.833_774 * 4 + 18446744073709551580)
>>>> inv_expr 2:     sudoku_351(D) + ((sizetype) S.833_774 + 72) * 4
>>>> inv_expr 3:     sudoku_351(D) + ((sizetype) S.833_774 + 81) * 4
>>>> inv_expr 4:     &A.832 + (sizetype) _377 * 4
>>>> inv_expr 5:     &A.832 + ((sizetype) _377 * 4 + 18446744073709551612)
>>>> inv_expr 6:     &A.832 + ((sizetype) _377 + 8) * 4
>>>> inv_expr 7:     &A.832 + ((sizetype) _377 + 9) * 4
>>>>
>>>> <Group-candidate Costs>:
>>>> Group 0:
>>>>   cand  cost    scaled  freq    compl.  depends on
>>>>
>>>> ...
>>>>
>>>> Improved to:
>>>>   cost: 27 (complexity 2)
>>>>   cand_cost: 11
>>>>   cand_group_cost: 10 (complexity 2)
>>>>   candidates: 3, 5
>>>>    group:0 --> iv_cand:5, cost=(2,0)
>>>>    group:1 --> iv_cand:5, cost=(4,1)
>>>>    group:2 --> iv_cand:5, cost=(4,1)
>>>>    group:3 --> iv_cand:3, cost=(0,0)
>>>>    group:4 --> iv_cand:3, cost=(0,0)
>>>>   invariants 1, 6
>>>>   invariant expressions 6, 3
>>>>
>>>> The only question here is that as used_inv_exprs are stored in a hash_map,
>>>> order of dumped invariants would not be stable. Is it problem?
>>> It is okay.
>>>
>>> Only nitpicking on this version.
>>>
>>>>
>>>>>>
>>>>>> + As check_GNU_style.sh reported multiple 8 spaces issues in hunks I've touched, I decided
>>>>>> to fix all 8 spaces issues. Hope it's fine.
>>>>>>
>>>>>> I'm going to test the patch.
>>>>>> Thoughts?
>>>>>
>>>>> Some comments on the patch embedded.
>>>>>
>>>>>>
>>>>>> +/* Forward declaration.  */
>>>>> Not necessary.
>>>>>> +struct iv_inv_expr_ent;
>>>>>> +
>>>>
>>>> I think it's needed because struct cost_pair uses a pointer to iv_inv_expr_ent.
>>> I mean the comment, clearly the declaration is self-documented.
>>
>> Hi.
>>
>> Yeah, removed.
>>
>>>
>>>> @@ -6000,11 +6045,12 @@ iv_ca_set_no_cp (struct ivopts_data *data, struct iv_ca *ivs,
>>>>
>>>>    iv_ca_set_remove_invariants (ivs, cp->depends_on);
>>>>
>>>> -  if (cp->inv_expr_id != -1)
>>>> +  if (cp->inv_expr != NULL)
>>>>      {
>>>> -      ivs->used_inv_expr[cp->inv_expr_id]--;
>>>> -      if (ivs->used_inv_expr[cp->inv_expr_id] == 0)
>>>> -        ivs->num_used_inv_expr--;
>>>> +      unsigned *slot = ivs->used_inv_exprs->get (cp->inv_expr);
>>>> +      --(*slot);
>>>> +      if (*slot == 0)
>>>> +    ivs->used_inv_exprs->remove (cp->inv_expr);
>>> I suppose insertion/removal of hash_map are not expensive?  Because
>>> the algorithm causes a lot of these operations.
>>
>> I think it should be ~ a constant operation.
>>
>>>
>>>> @@ -6324,12 +6368,26 @@ iv_ca_dump (struct ivopts_data *data, FILE *file, struct iv_ca *ivs)
>>>>      fprintf (file, "   group:%d --> ??\n", group->id);
>>>>      }
>>>>
>>>> +  bool any_invariant = false;
>>>>    for (i = 1; i <= data->max_inv_id; i++)
>>>>      if (ivs->n_invariant_uses[i])
>>>>        {
>>>> +    const char *pref = any_invariant ? ", " : "  invariants ";
>>>> +    any_invariant = true;
>>>>      fprintf (file, "%s%d", pref, i);
>>>> -    pref = ", ";
>>>>        }
>>>> +
>>>> +  if (any_invariant)
>>>> +    fprintf (file, "\n");
>>>> +
>>> To make dump easier to read, we can simply dump invariant
>>> variables/expressions unconditionally.  Also keep invariant variables
>>> and expressions in the same form.
>>
>> Sure, that's a good idea!
>>
>> Sample output:
>>
>>
>> Initial set of candidates:
>>   cost: 17 (complexity 0)
>>   cand_cost: 11
>>   cand_group_cost: 2 (complexity 0)
>>   candidates: 1, 5
>>    group:0 --> iv_cand:5, cost=(2,0)
>>    group:1 --> iv_cand:1, cost=(0,0)
>>   invariant variables: 1, 4
>>   invariant expressions:
>>
>> Initial set of candidates:
>>   cost: 42 (complexity 2)
>>   cand_cost: 15
>>   cand_group_cost: 12 (complexity 2)
>>   candidates: 4, 15, 16
>>    group:0 --> iv_cand:16, cost=(0,0)
>>    group:1 --> iv_cand:15, cost=(-1,0)
>>    group:2 --> iv_cand:4, cost=(0,0)
>>    group:3 --> iv_cand:15, cost=(9,1)
>>    group:4 --> iv_cand:15, cost=(4,1)
>>   invariant variables:
>>   invariant expressions:
>>
>>>    const char *pref = "";
>>>    //...
>>>    fprintf (file, "  invariant variables: "
>>>    for (i = 1; i <= data->max_inv_id; i++)
>>>      if (ivs->n_invariant_uses[i])
>>>        {
>>>      fprintf (file, "%s%d", pref, i);
>>>     pref = ", ";
>>>        }
>>>    fprintf (file, "\n");
>>>
>>>> +  const char *pref = "  invariant expressions ";
>>>> +  for (hash_map<iv_inv_expr_ent *, unsigned>::iterator it
>>>> +       = ivs->used_inv_exprs->begin (); it != ivs->used_inv_exprs->end (); ++it)
>>>> +    {
>>>> +    fprintf (file, "%s%d", pref, (*it).first->id);
>>>> +    pref = ", ";
>>>> +    }
>>>> +
>>>>    fprintf (file, "\n\n");
>>>>  }
>>>>
>>>
>>> Okay with the dump change,  you may need to update Changelog entry too.
>>
>> There's no fundamental change, thus not changing the ChangeLog entry.
>>
>> Thanks for the review, installed as r236200.
>>
> 
> It failed to build on 32-bit hosts:
> 
> ../../src-trunk/gcc/tree-ssa-loop-ivopts.c: In function \u2018void
> create_new_ivs(ivopts_data*, iv_ca*)\u2019:
> ../../src-trunk/gcc/tree-ssa-loop-ivopts.c:7050:44: error: format
> \u2018%lu\u2019 expects argument of type \u2018long unsigned
> int\u2019, but argument 3 has type \u2018long long int\u2019
> [-Werror=format=]
>          avg_loop_niter (data->current_loop));
>                                             ^
> ../../src-trunk/gcc/tree-ssa-loop-ivopts.c:7052:41: error: format
> \u2018%lu\u2019 expects argument of type \u2018long unsigned
> int\u2019, but argument 3 has type \u2018size_t {aka unsigned
> int}\u2019 [-Werror=format=]
>          set->used_inv_exprs->elements ());
>                                          ^
> 
> 
> 

Hi.

Thanks for heads up, can you please test the following patch?

Thanks,
Martin

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From 32a2da9a7f327f60401cec5c7ab2fa5ba633561f Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Fri, 13 May 2016 14:37:45 +0200
Subject: [PATCH] IVOPTS dump fall-out

gcc/ChangeLog:

2016-05-13  Martin Liska  <mliska@suse.cz>

	* tree-ssa-loop-ivopts.c (create_new_ivs): Use PRIu64 and PRId64
	in printf format.
---
 gcc/tree-ssa-loop-ivopts.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 62b8835..abfe73d 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -7046,9 +7046,9 @@ create_new_ivs (struct ivopts_data *data, struct iv_ca *set)
       if (data->loop_loc != UNKNOWN_LOCATION)
 	fprintf (dump_file, " at %s:%d", LOCATION_FILE (data->loop_loc),
 		 LOCATION_LINE (data->loop_loc));
-      fprintf (dump_file, ", %lu avg niters",
+      fprintf (dump_file, ", %" PRId64 " avg niters",
 	       avg_loop_niter (data->current_loop));
-      fprintf (dump_file, ", %lu expressions",
+      fprintf (dump_file, ", %" PRIu64 " expressions",
 	       set->used_inv_exprs->elements ());
       fprintf (dump_file, ", %lu IVs:\n", bitmap_count_bits (set->cands));
       EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi)
-- 
2.8.2