On 26/01/16 17:59, Sebastian Pop wrote:
> Tom de Vries wrote:
>> diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
>> index a40f40d..4c29fc2 100644
>> --- a/gcc/tree-data-ref.c
>> +++ b/gcc/tree-data-ref.c
>> @@ -1510,8 +1510,9 @@ initialize_data_dependence_relation (struct data_reference *a,
>>     if (operand_equal_p (DR_REF (a), DR_REF (b), 0))
>>       {
>>        if (loop_nest.exists ()
>> -        && !object_address_invariant_in_loop_p (loop_nest[0],
>> -       					        DR_BASE_OBJECT (a)))
>> +	 && (!object_address_invariant_in_loop_p (loop_nest[0],
>> +						  DR_BASE_OBJECT (a))
>> +	     || DR_NUM_DIMENSIONS (a) == 0))
>
> Also please fix the indentation of all this if stmt.
>

Done.

>>         {
>>           DDR_ARE_DEPENDENT (res) = chrec_dont_know;
>>           return res;
>> @@ -1548,8 +1549,9 @@ initialize_data_dependence_relation (struct data_reference *a,
>>        analyze it.  TODO -- in fact, it would suffice to record that there may
>>        be arbitrary dependences in the loops where the base object varies.  */
>>     if (loop_nest.exists ()
>> -      && !object_address_invariant_in_loop_p (loop_nest[0],
>> -     					      DR_BASE_OBJECT (a)))
>> +      && (!object_address_invariant_in_loop_p (loop_nest[0],
>> +					       DR_BASE_OBJECT (a))
>> +	  || DR_NUM_DIMENSIONS (a) == 0))
>>       {
>>         DDR_ARE_DEPENDENT (res) = chrec_dont_know;
>>         return res;
>
> Let's check for DR_NUM_DIMENSIONS (a) == 0 independently of loop_nest.exists ().

Done.

> We check for the loop_nest because we need to access the outer loop loop_nest[0]
> to analyze the base object of a.
>
> Otherwise the change looks good to me.
>

Bootstrapped and reg-tested on x86_64.

Committed as attached to trunk, 5.0 and 4.9 (And fixed up pass number in 
testcases in 5.0 and 4.9).

Thanks,
- Tom