[Mesa-dev] [PATCH v2 3/3] glsl: disable array splitting for AoA

[Jason Ekstrand]

I'd like the chance to look at these, please.  I'm on vacation today and 
tomorrow though.


On July 3, 2017 7:19:04 AM funfunctor at folklore1984.net wrote:

> On 2017-07-03 08:47, Timothy Arceri wrote:
>> While it produces functioning code the pass creates worse code
>> for arrays of arrays. See the comment added in this patch for more
>> detail.
>>
>> V2: skip splitting of AoA of matrices too.
>
> Reviewed-by: Edward O'Callaghan <funfunctor at folklore1984.net>
>
>> ---
>>  src/compiler/glsl/opt_array_splitting.cpp | 23 +++++++++++++++++++++++
>>  1 file changed, 23 insertions(+)
>>
>> diff --git a/src/compiler/glsl/opt_array_splitting.cpp
>> b/src/compiler/glsl/opt_array_splitting.cpp
>> index fb6d77b..d2e81665 100644
>> --- a/src/compiler/glsl/opt_array_splitting.cpp
>> +++ b/src/compiler/glsl/opt_array_splitting.cpp
>> @@ -140,6 +140,29 @@
>> ir_array_reference_visitor::get_variable_entry(ir_variable *var)
>>     if (var->type->is_unsized_array())
>>        return NULL;
>>
>> +   /* FIXME: arrays of arrays are not handled correctly by this pass
>> so we
>> +    * skip it for now. While the pass will create functioning code it
>> actually
>> +    * produces worse code.
>> +    *
>> +    * For example the array:
>> +    *
>> +    *    int[3][2] a;
>> +    *
>> +    * ends up being split up into:
>> +    *
>> +    *    int[3][2] a_0;
>> +    *    int[3][2] a_1;
>> +    *    int[3][2] a_2;
>> +    *
>> +    * And we end up referencing each of these new arrays for example:
>> +    *
>> +    *    a[0][1] will be turned into a_0[0][1]
>> +    *    a[1][0] will be turned into a_1[1][0]
>> +    *    a[2][0] will be turned into a_2[2][0]
>> +    */
>> +   if (var->type->is_array() && var->type->fields.array->is_array())
>> +      return NULL;
>> +
>>     foreach_in_list(variable_entry, entry, &this->variable_list) {
>>        if (entry->var == var)
>>           return entry;
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev