[PATCH] R600/SI: Allow commuting some 3 op instructions

[Matt Arsenault]

> On Oct 21, 2014, at 9:26 AM, Matt Arsenault <arsenm2 at gmail.com> wrote:
> 
>> 
>> On Oct 21, 2014, at 6:38 AM, Tom Stellard <tom at stellard.net> wrote:
>> 
>> On Sat, Oct 18, 2014 at 01:57:11AM +0000, Matt Arsenault wrote:
>>> e.g. v_mad_f32 a, b, c -> v_mad_f32 b, a, c
>>> 
>>> This simplifies matching v_madmk_f32.
>>> 
>>> This looks somewhat surprising, but it appears to be
>>> OK to do this. We can commute src0 and src1 in all
>>> of these instructions, and that's all that appears
>>> to matter.
>>> 
>> 
>> Are there any advantages to being able to commute VOP3 instructions?
>> 
>> -Tom
> 
> Mostly just canonicalization to simplify other checks. For example, I have another patch that forms v_madmk_f32 which relies on this to avoid checking for an immediate in the 2nd operand


ping
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20141031/10da3662/attachment.html>