[PATCH] D46992: [AMDGPU] Add perf hints to functions

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec added a comment.

In https://reviews.llvm.org/D46992#1105803, @mareko wrote:

> In https://reviews.llvm.org/D46992#1105636, @rampitec wrote:
>
> > In https://reviews.llvm.org/D46992#1105635, @mareko wrote:
> >
> > > How does this pass affect shaders that use a lot of memory instructions but no pointers?
> >
> >
> > Can you give an example? What is a memory instruction without a pointer? As you may see, pass processes something which can cast to load, store, atomic or memory intrinsic. Everything else considered an ordinary instruction. For example if have an image in mind it is conservatively not considered memory instruction.
>
>
> A memory instruction that doesn't use a pointer is an instruction that uses a resource descriptor (buffer or image). The majority of non-compute workloads use resource descriptors for all memory accesses (except those that load descriptors from memory).


Ok, that's what I meant, it is considered an ordinary instruction. It is just not covered by the pass and there is no impact. Primarily because no measurements were done, no workloads analyzed and no statistics collected to try to perform any optimizations of that kind on compute side. gfx side may have data collected, but the pass will do nothing to that kind of loads.


https://reviews.llvm.org/D46992