[PATCH] AMDGPU: don't match vgpr loads for constant loads

[David Airlie]

> 
> 
> > On Jul 24, 2015, at 4:15 PM, Marek Olšák <maraeo at gmail.com> wrote:
> > 
> > Hi Matt,
> > 
> > Aren't scalar loads converted to vector loads when the operands are
> > legalized?
> > 
> > Marek
> 
> They should be. There are a handful of tests already for this in
> salu-to-valu.ll, although their check lines aren’t strict enough to show the
> suboptimal addressing mode matching caused by doing this. Adding one that
> uses a large maximum mubuf immediate offset (i.e <4096 bytes) but larger
> than the SMRD offset can handle (256 dwords) that isn’t folded into the
> mubuf offset would be useful to track this defect.

So don't these tests do what you asked me to do already, it seems they used tidig.x
and one adds a value to it.

This stuff is well beyond my current knowledge of the compiler, I just found what fixed the bug I was seeing in mesa that is blocking us from enabling ARB_gpu_shader5 and subsequently GL4, I'm not sure I have the correct knowledge to write a unit test for some side effects of fixing this bug.

Dave.