[PATCH] D26725: AMDGPU: Add llvm.amdgcn.interp.mov intrinsic

[Marek Olšák via llvm-commits]

mareko added inline comments.


================
Comment at: include/llvm/IR/IntrinsicsAMDGPU.td:481
+            [llvm_i32_ty, llvm_i32_ty, llvm_i32_ty, llvm_i32_ty],
+            [IntrNoMem]>;
+
----------------
nhaehnle wrote:
> arsenm wrote:
> > nhaehnle wrote:
> > > tstellarAMD wrote:
> > > > arsenm wrote:
> > > > > Shouldn't this be IntrReadMem? The doc says it reads parameters in LDS
> > > > I think technically, this should be inaccessiblememonly,  because but there is no intrinsic attribute for this yet.
> > > And that region of LDS is constant anyway, so IntrNoMem is fine.
> > Is that possible? I thought the runtime couldn't ever initialize LDS, so something in the shader has to set it in the first place
> The LDS for these instructions is initialized by Primitive Assembly (or possibly the Scan Converter, it's unclear to me where the boundary between those hardware blocks is precisely).
LDS is initialized by the SPI block before the pixel shader. ReadNone is fine, because nothing can modify it.


https://reviews.llvm.org/D26725