[llvm] [WIP][AMDGPU] Make `getAssumedAddrSpace` return AS1 for pointer kernel arguments (PR #137488)

[Shilei Tian via llvm-commits]

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@@ -951,6 +951,10 @@ bool AMDGPUTargetMachine::isNoopAddrSpaceCast(unsigned SrcAS,
 }
 
 unsigned AMDGPUTargetMachine::getAssumedAddrSpace(const Value *V) const {
+  if (auto *Arg = dyn_cast<Argument>(V);
+      Arg && AMDGPU::isKernelCC(Arg->getParent()))
+    return AMDGPUAS::GLOBAL_ADDRESS;
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shiltian wrote:

If we have something like `ptr byref(i32) %in.byref`, I suppose it is also in AS1?

https://github.com/llvm/llvm-project/pull/137488