[llvm] [llvm][NVPTX] Inform that 'DYNAMIC_STACKALLOC' is unsupported (PR #74684)

[Youngsuk Kim via llvm-commits]

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@@ -2652,6 +2657,9 @@ NVPTXTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   case ISD::SREM:
   case ISD::UREM:
     return LowerVectorArith(Op, DAG);
+  case ISD::DYNAMIC_STACKALLOC:
+    report_fatal_error(
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JOE1994 wrote:

Thanks for your feedback!
I'll update the PR to trigger a diagnostic instead.

P.s.
I mimicked the `report_fatal_error` approach from BPFISelLowering.
That part could use a similar improvement as well.

https://github.com/llvm/llvm-project/blob/a2161154334355e9ecdf3cc3a0303b9481aad897/llvm/lib/Target/BPF/BPFISelLowering.cpp#L311 .

https://github.com/llvm/llvm-project/pull/74684