[Mesa-dev] [PATCH 01/10] gallivm: supply correct opcode info to emit functions

[Marek Olšák]

On Sun, Oct 11, 2015 at 4:22 AM, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 11.10.2015 um 03:29 schrieb Marek Olšák:
>> From: Marek Olšák <marek.olsak at amd.com>
>>
>> This is useful only when emit functions use it.
>> The new radeonsi min/max opcode implementation requires this.
>> ---
>>  src/gallium/auxiliary/gallivm/lp_bld_tgsi.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> index c4ae304..c50d83e 100644
>> --- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> +++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> @@ -114,12 +114,17 @@ lp_build_emit_llvm(
>>     struct lp_build_emit_data * emit_data)
>>  {
>>     struct lp_build_tgsi_action * action = &bld_base->op_actions[tgsi_opcode];
>> +   const struct tgsi_opcode_info *old_info = emit_data->info;
>>     /* XXX: Assert that this is a componentwise or replicate instruction */
>>
>>     lp_build_action_set_dst_type(emit_data, bld_base, tgsi_opcode);
>>     emit_data->chan = 0;
>> +
>> +   /* Set and restore the opcode info. */
>> +   emit_data->info = tgsi_get_opcode_info(tgsi_opcode);
>>     assert(action->emit);
>>     action->emit(action, bld_base, emit_data);
>> +   emit_data->info = old_info;
>>     return emit_data->output[0];
>>  }
>>
>>
>
> Could you elaborate why this is necessary? Looks like a hack and I can't
> see why opcode info would be wrong in the first place. Or if that's
> never set correctly and you just need it to be able to distinguish
> min/max later, I'd suggest you shouldn't do that and just use different
> functions.

lp_build_emit_llvm_binary and friends don't set the opcode info at all
and they also don't set the instruction info. This means the emit
function has no way to tell which opcode is being processed if that
emit function is used for multiple opcodes.

Marek