[clang] [llvm] [mlir] [AMDGPU] Add ptr.s.buffer.load intrinsic, use it from Clang (PR #209243)

[Krzysztof Drewniak via cfe-commits]

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@@ -1485,6 +1485,33 @@ def int_amdgcn_s_buffer_load : DefaultAttrsIntrinsic <
   [IntrNoMem, ImmArg<ArgIndex<2>>]>,
   AMDGPURsrcIntrinsic<0>;
 
+// Generate an s_buffer_load instruction, falling back to buffer_load if the offset
+// is not uniform. This operates like the s.buffer.load intrinsic, but uses a buffer
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krzysz00 wrote:

I think s_buffer_load is documented weird, given that it's got those "no memory" semantics and all.

Both of these are an s_buffer_load when all the arguments are uniform and a buffer_load otherwise, I just wrote the docs on this one as "you're explicitly requesting a uniform load".

https://github.com/llvm/llvm-project/pull/209243