[llvm-branch-commits] [llvm] AMDGPU: Fix buffer load/store of pointers (PR #95379)

[Krzysztof Drewniak via llvm-branch-commits]

krzysz00 wrote:

On the other hand, it's a lot easier to handle ugly types down in instruction selection, where you get to play much more fast and loose with types.

And there are buffer uses that don't fit into the fat pointer use use case where we'd still want them to work.
For example, both `str
uct.ptr.bufferload.v6f16` and `struct.ptr.buffer.load.v3f32` should be a `buffer_load_dwordx3`, but I'm pretty sure 6 x half isn't a register type.

The load and store intrinsics are already overloaded to handle various {8, 16, ..., 128}-bit types, and it seems much cleaner to let it support any type of those lengths. It's just a load/store with somewhat weird indexing semantics, is all.

And then, since we're there ... `load i256, ptr addrspace(1) %p` legalizes to multiple instructions, and `{raw,struct}.ptr.buffer.load(ptr addrspace(8) %p, i32 %offset, ...)` should too. It's just a load, after all.

https://github.com/llvm/llvm-project/pull/95379