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

[Yingchi Long 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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inclyc wrote:

FWIW, using `report_fatal_error` will also generate stack dumps, which is misleading for a compiler bug.

The correctly way to do such thing is trigger a diagnostic, and let the frontend (e.g. clang) to report it.

See: https://github.com/llvm/llvm-project/blob/1d56138d741ebec81ac7a6dada10f5d6b891a768/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp#L1291C1-L1300C2


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