[Mesa-dev] [PATCH 1/5] st/mesa: also emit labels for TGSI_OPCODE_BGNSUB

[Brian Paul]

On 04/14/2015 02:20 PM, Jose Fonseca wrote:
> On 14/04/15 17:56, Brian Paul wrote:
>> Subroutines need labels so they can be identied by CAL instructions.
>> ---
>>   src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 19 +++++++++++++------
>>   1 file changed, 13 insertions(+), 6 deletions(-)
>>
>> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> index 67a4da7..eb0ce07 100644
>> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> @@ -4771,18 +4771,25 @@ compile_tgsi_instruction(struct st_translate *t,
>>      }
>>
>>      switch(inst->op) {
>> +   case TGSI_OPCODE_BGNSUB:
>>      case TGSI_OPCODE_BGNLOOP:
>>      case TGSI_OPCODE_CAL:
>>      case TGSI_OPCODE_ELSE:
>>      case TGSI_OPCODE_ENDLOOP:
>>      case TGSI_OPCODE_IF:
>>      case TGSI_OPCODE_UIF:
>> -      assert(num_dst == 0);
>> -      ureg_label_insn(ureg,
>> -                      inst->op,
>> -                      src, num_src,
>> -                      get_label(t,
>> -                                inst->op == TGSI_OPCODE_CAL ?
>> inst->function->sig_id : 0));
>> +      {
>> +         int sig_id = 0;
>> +         if (inst->op == TGSI_OPCODE_CAL ||
>> +             inst->op == TGSI_OPCODE_BGNSUB) {
>
> I'm not sure about this.
>
> One thing is the label of the instruction (ie, instrution no), the other
> is the operand label.
>
> CAL takes an operand label (the #no of the instruction where BGNSUB
> starts).
>
> But BGNSUB shouldn't need a label (what matter is the instrucion #no).
> If it does take a label, then it's probably the label of the ENDSUB, not
> where the function starts.
>
>
> I thought we had removed all these pointless labels.  I suppose that's
> why the label 0 is used.  In other words, I believe the right thing here
> is to add the case statement for TGSI_OPCODE_BGNSUB, but not treat it
> like CAL.

Hmm, OK, I'll have to take another look at this when I can find some 
time.  I know labels were kind of iffy...

-Brian