[PATCH 1/5] R600: Expand vector sin and cos on r600.

Christian K├Ânig deathsimple at vodafone.de
Tue Apr 22 04:36:43 PDT 2014


> So there's no way to make vector elements to work items, and execute
> only one instruction? I should read the specs more carefully.

No, at least not a halve way sane one. Work items are controlled by the 
application, e.g. it's the parallelization of work into different 
execution thread as exposed by interfaces like OpenCL or OpenGL.

But the vector instructions of LLVM are parallelization of work by 
working on multiple data elements in the same thread.

Don't be confused allot of people mix that up,
Christian.

Am 22.04.2014 03:16, schrieb Jan Vesely:
> On Mon, 2014-04-21 at 13:51 -0700, Tom Stellard wrote:
>> On Sun, Apr 20, 2014 at 04:57:51PM -0400, Jan Vesely wrote:
>>> Signed-off-by: Jan Vesely <jan.vesely at rutgers.edu>
>>> ---
>>>   lib/Target/R600/R600ISelLowering.cpp | 11 +++++++++++
>>>   1 file changed, 11 insertions(+)
>>>
>>> diff --git a/lib/Target/R600/R600ISelLowering.cpp b/lib/Target/R600/R600ISelLowering.cpp
>>> index ecffee2..a6304d8 100644
>>> --- a/lib/Target/R600/R600ISelLowering.cpp
>>> +++ b/lib/Target/R600/R600ISelLowering.cpp
>>> @@ -141,6 +141,17 @@ R600TargetLowering::R600TargetLowering(TargetMachine &TM) :
>>>     setTargetDAGCombine(ISD::SELECT_CC);
>>>     setTargetDAGCombine(ISD::INSERT_VECTOR_ELT);
>>>   
>>> +  static const MVT::SimpleValueType FloatTypes[] = {
>>> +    MVT::v2f32, MVT::v4f32
>>> +  };
>>> +  const size_t NumFloatTypes = array_lengthof(FloatTypes);
>>> +
>>> +  for (unsigned int x = 0; x < NumFloatTypes; ++x) {
>>> +    MVT::SimpleValueType VT = FloatTypes[x];
>>> +    setOperationAction(ISD::FCOS, VT, Expand);
>>> +    setOperationAction(ISD::FSIN, VT, Expand);
>>> +  }
>>> +
>> There actually aren't vector instructions for these on SI, so this
>> should go in AMDGPUISelLowering.cpp.  It's confusing because the instructions
>> V_SIN_F32 and V_COS_F32 are 'Vector Instructions', but in this case it means they
>> execute on a vector of work items, and each work item provides scalar input.
> So there's no way to make vector elements to work items, and execute
> only one instruction? I should read the specs more carefully.
>
> I've attached v2, simplified and squashed with tests(including SI).
>
> regards,
> Jan
>
>> -Tom
>>
>>>     setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
>>>   
>>>     setBooleanContents(ZeroOrNegativeOneBooleanContent);
>>> -- 
>>> 1.9.0
>>>
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