[Mesa-dev] [PATCH 2/2] gk110/ir: use separate signed expressions for dst/src with IMUL32I

[Samuel Pitoiset]

On 04/20/2016 10:13 PM, Ilia Mirkin wrote:
> On Wed, Apr 20, 2016 at 3:14 PM, Samuel Pitoiset
> <samuel.pitoiset at gmail.com> wrote:
>>
>>
>> On 04/20/2016 07:47 PM, Ilia Mirkin wrote:
>>>
>>> Presumably you'd want to touch up the non-limm side of this as well?
>>> Although TBH, I can't really think of a time when it'd matter. I think
>>> you're pretty much guaranteed to have stype == dtype for mul's. Maybe
>>> I'm wrong?
>>
>>
>> Well, the non-limm part is wrong because 0xc1c won't be used anymore with
>> the previous patch, as emitForm_21() uses opc1 when src(1) is an immediate.
>> The different flags was only useful for 0xc1c but now they are useless,
>> because 0x21c is actually:
>>
>> /*0000*/   @P0 FMUL32I.FTZ R0.CC, R0, -0;      /* 0x21c0000000000002 */
>
> huh? It or's some bits depending on arg types, so it'll be 61c or whatever.

Mmmh, this needs to be verified.

>
>>
>> I was thinking to make a new patch to remove them, but this one doesn't need
>> to be backported.
>>
>> I think we are pretty guaranteed that stype == dtype, but does this is
>> correct all the time? Not sure. If you look at NVC0::emitUMUL() you will see
>> that the signed expressions for dst/src are separated.
>>
>>
>>>
>>>     -ilia
>>>
>>> On Wed, Apr 20, 2016 at 1:06 PM, Samuel Pitoiset
>>> <samuel.pitoiset at gmail.com> wrote:
>>>>
>>>> Forcing the destination type to be signed when the source is signed
>>>> is not totally correct.
>>>>
>>>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
>>>> Cc: "11.1 11.2" <mesa-stable at lists.freedesktop.org>
>>>> ---
>>>>    src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp | 4 +++-
>>>>    1 file changed, 3 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
>>>> b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
>>>> index f69567a..90b90bc 100644
>>>> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
>>>> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
>>>> @@ -617,8 +617,10 @@ CodeEmitterGK110::emitIMUL(const Instruction *i)
>>>>
>>>>          if (i->subOp == NV50_IR_SUBOP_MUL_HIGH)
>>>>             code[1] |= 1 << 24;
>>>> +      if (i->dType == TYPE_S32)
>>>> +         code[1] |= 1 << 25;
>>>>          if (i->sType == TYPE_S32)
>>>> -         code[1] |= 3 << 25;
>>>> +         code[1] |= 1 << 26;
>>>>       } else {
>>>>          emitForm_21(i, 0x21c, 0xc1c);
>>>>
>>>> --
>>>> 2.8.0
>>>>
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