[Mesa-dev] [PATCH] R600/SI: Use MULADD_IEEE/V_MAD_F32 instruction for mad pattern

[Christian König]

Am 11.02.2013 15:35, schrieb Michel Dänzer:
> On Son, 2013-02-10 at 19:38 +0100, Vincent Lejeune wrote:
>> diff --git a/lib/Target/R600/SIInstructions.td b/lib/Target/R600/SIInstructions.td
>> index a09f243..7e50e86 100644
>> --- a/lib/Target/R600/SIInstructions.td
>> +++ b/lib/Target/R600/SIInstructions.td
>> @@ -1423,8 +1423,8 @@ def : Pat <
>>   /**********   VOP3 Patterns    **********/
>>   /********** ================== **********/
>>   
>> -def : Pat <(f32 (IL_mad AllReg_32:$src0, VReg_32:$src1, VReg_32:$src2)),
>> -           (V_MAD_LEGACY_F32 AllReg_32:$src0, VReg_32:$src1, VReg_32:$src2,
>> +def : Pat <(f32 (fadd (fmul AllReg_32:$src0, VReg_32:$src1), VReg_32:$src2)),
>> +           (V_MAD_F32 AllReg_32:$src0, VReg_32:$src1, VReg_32:$src2,
>>               0, 0, 0, 0)>;
> I still feel a bit uneasy about applying the SI changes without fully
> understanding why they break those piglit tests. Though I guess it might
> be okay if you're not targetting this for the Mesa stable branch...
> Tom / Christian, what's your opinion on this?

I think I'm on the way figuring out what's going wrong here. One step is 
that the _e64 encoding of (for example) V_CND_* is slightly wrong and 
working only by coincident, but there seems to be at least one more 
thing quite wrong here.

Give me a day or two I've coded a whole bunch of patches while on 
vacation (including a fix for this), but I doesn't have the hardware 
here to test them.

Christian.