[PATCH] D125060: [amdgpu] Implement lds kernel id intrinsic

[Jon Chesterfield via Phabricator via llvm-commits]

JonChesterfield added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h:107
 
+  static ConstantInt *getLDSKernelIdMetadata(const Function &F);
+
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arsenm wrote:
> Why not return the int value?
ConstantInt is the return type of mdconst::extract and this gives a cheap/lazy way to test for the metadata missing (returning nullptr). Replaced with std::optional<uint32_t> for more explicit/verbose uses at the call sites.


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Comment at: llvm/lib/Target/AMDGPU/SIISelLowering.cpp:2826
+      } else {
+        InputReg = DAG.getUNDEF(ArgVT);
+      }
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arsenm wrote:
> This should get a test in abi-attribute-hints-undefined-behavior.ll
Added the clause, but obv no change to codegen as it lowers to undef on missing


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  https://reviews.llvm.org/D125060/new/

https://reviews.llvm.org/D125060