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

Matt Arsenault arsenm2 at gmail.com
Wed Aug 6 10:34:05 PDT 2014


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.
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