[PATCH] R600/SI: Use source modifiers for f64 fabs / fneg

[Matt Arsenault]

On Aug 15, 2014, at 9:13 AM, Tom Stellard <tom at stellard.net> wrote:

> On Wed, Aug 06, 2014 at 06:56:37PM -0700, Matt Arsenault wrote:
> 
> LGTM.
> 
>> 
>> On Aug 6, 2014, at 10:34 AM, Matt Arsenault <arsenm2 at gmail.com> wrote:
>> 
>>> 
>>> On Aug 6, 2014, at 12:25 AM, Michel Dänzer <michel at daenzer.net> wrote:
>>> 
>>>> 
>>>>> Here is an updated set that implements that for f64. These also
>>>>> switch to preferring using the literal constant as the first operand,
>>>>> rather than loading the immediate into a register.
>>>> 
>>>> Sounds good, but I have to defer to Tom or others for review.
>>>> 
>>> 
>>> I think I’m going to go back on this. It’s mostly a cosmetic change in the scalar case, trading a move of an immediate for one from an SGPR to VGPR. In the vector case, this would require N SGPR copies, but the other way the SGPRs could stay and only 1 copy of the immediate would need to be loaded.
>> 
>> 
>> 
>> These switch back to preferring the old order of literal loaded into a VGPR, and remove the FABS_SI / FNEG_SI pseudoinstructions. I don’t see any need for them anymore, and the pattern can directly match the instructions
>> 
>> 
> 
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r215746 - r215749
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