[PR65511] Fix edge probabilities in gimple_duplicate_sese_tail

On 30-03-15 10:15, Jan Hubicka wrote:
>> diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
>> index 64bdc92..c7a7c4d 100644
>> --- a/gcc/tree-cfg.c
>> +++ b/gcc/tree-cfg.c
>> @@ -6177,6 +6177,7 @@ gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNU
>>     gphi *phi;
>>     tree def;
>>     struct loop *target, *aloop, *cloop;
>> +  int exit_prob = exit->probability;
>>
>>     gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
>>     exits[0] = exit;
>> @@ -6268,6 +6269,8 @@ gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNU
>>     sorig = single_succ_edge (switch_bb);
>>     sorig->flags = exits[1]->flags;
>>     snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
>> +  snew->probability = exit_prob;
>> +  sorig->probability = REG_BR_PROB_BASE - exit_prob;
> You need to also set snew->count/sorig->count.
>

Thanks for noting that. Updated patch.

OK for stage1 if bootstrap and reg-test on x86_64 are ok?

Thanks,
- Tom

On 30/03/15 11:54, Tom de Vries wrote:
> On 30-03-15 10:15, Jan Hubicka wrote:
>>> diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
>>> index 64bdc92..c7a7c4d 100644
>>> --- a/gcc/tree-cfg.c
>>> +++ b/gcc/tree-cfg.c
>>> @@ -6177,6 +6177,7 @@ gimple_duplicate_sese_tail (edge entry
>>> ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNU
>>>     gphi *phi;
>>>     tree def;
>>>     struct loop *target, *aloop, *cloop;
>>> +  int exit_prob = exit->probability;
>>>
>>>     gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
>>>     exits[0] = exit;
>>> @@ -6268,6 +6269,8 @@ gimple_duplicate_sese_tail (edge entry
>>> ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNU
>>>     sorig = single_succ_edge (switch_bb);
>>>     sorig->flags = exits[1]->flags;
>>>     snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
>>> +  snew->probability = exit_prob;
>>> +  sorig->probability = REG_BR_PROB_BASE - exit_prob;
>> You need to also set snew->count/sorig->count.
>>
>
> Thanks for noting that. Updated patch.
>
> OK for stage1 if bootstrap and reg-test on x86_64 are ok?
>

Ping. Original posting at 
https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01536.html .

Thanks,
- Tom


> 0001-Fix-edge-probabilities-in-gimple_duplicate_sese_tail.patch
>
>
> Fix edge probabilities in gimple_duplicate_sese_tail
>
> 2015-03-27  Tom de Vries<tom@codesourcery.com>
>
> 	PR tree-optimization/65511
> 	* tree-cfg.c (gimple_duplicate_sese_tail): Fix edge probabilities and
> 	counts.
>
> 	* gcc.dg/parloops-prob.c: New test.
> ---
>   gcc/testsuite/gcc.dg/parloops-prob.c | 21 +++++++++++++++++++++
>   gcc/tree-cfg.c                       | 11 +++++++++++
>   2 files changed, 32 insertions(+)
>   create mode 100644 gcc/testsuite/gcc.dg/parloops-prob.c
>
> diff --git a/gcc/testsuite/gcc.dg/parloops-prob.c b/gcc/testsuite/gcc.dg/parloops-prob.c
> new file mode 100644
> index 0000000..a3e767c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/parloops-prob.c
> @@ -0,0 +1,21 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target pthread } */
> +/* { dg-options "-O2 -ftree-parallelize-loops=2 -fdump-tree-fixup_cfg4-all" } */
> +
> +#define N 1000
> +
> +unsigned int a[N];
> +unsigned int b[N];
> +unsigned int c[N];
> +
> +void
> +f (unsigned int n)
> +{
> +  int i;
> +
> +  for (i = 0; i < n; ++i)
> +    c[i] = a[i] + b[i];
> +}
> +
> +/* { dg-final { scan-tree-dump-not "freq 0" "fixup_cfg4" } } */
> +/* { dg-final { cleanup-tree-dump "fixup_cfg4" } } */
> diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
> index 64bdc92..6db6dff 100644
> --- a/gcc/tree-cfg.c
> +++ b/gcc/tree-cfg.c
> @@ -6177,11 +6177,18 @@ gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNU
>     gphi *phi;
>     tree def;
>     struct loop *target, *aloop, *cloop;
> +  int exits_prob[2];
> +  gcov_type exits_count[2];
>
>     gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
>     exits[0] = exit;
>     exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
>
> +  exits_prob[0] = exits[0]->probability;
> +  exits_prob[1] = exits[1]->probability;
> +  exits_count[0] = exits[0]->count;
> +  exits_count[1] = exits[1]->count;
> +
>     if (!can_copy_bbs_p (region, n_region))
>       return false;
>
> @@ -6268,6 +6275,10 @@ gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNU
>     sorig = single_succ_edge (switch_bb);
>     sorig->flags = exits[1]->flags;
>     snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
> +  snew->probability = exits_prob[0];
> +  snew->count = exits_count[0];
> +  sorig->probability = exits_prob[1];
> +  sorig->count = exits_count[1];
>
>     /* Register the new edge from SWITCH_BB in loop exit lists.  */
>     rescan_loop_exit (snew, true, false);
> -- 1.9.1
>