[llvm] [NVPTX] Add support for stacksave, stackrestore intrinsics (PR #114484)

[Alex MacLean via llvm-commits]

================
@@ -2287,6 +2290,54 @@ SDValue NVPTXTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
   return DAG.getNode(NVPTXISD::DYNAMIC_STACKALLOC, DL, RetTypes, AllocOps);
 }
 
+SDValue NVPTXTargetLowering::LowerSTACKRESTORE(SDValue Op,
+                                               SelectionDAG &DAG) const {
+  SDLoc DL(Op.getNode());
+  if (STI.getPTXVersion() < 73 || STI.getSmVersion() < 52) {
+    const Function &Fn = DAG.getMachineFunction().getFunction();
+
+    DiagnosticInfoUnsupported NoStackRestore(
+        Fn,
+        "Support for stackrestore introduced in PTX ISA version 7.3 and "
+        "requires target sm_52.",
+        DL.getDebugLoc());
+    DAG.getContext()->diagnose(NoStackRestore);
+    return Op.getOperand(0);
+  }
+
+  const MVT LocalVT = getPointerTy(DAG.getDataLayout(), ADDRESS_SPACE_LOCAL);
+  SDValue Chain = Op.getOperand(0);
+  SDValue Ptr = Op.getOperand(1);
+  SDValue ASC = DAG.getAddrSpaceCast(DL, LocalVT, Ptr, ADDRESS_SPACE_GENERIC,
+                                     ADDRESS_SPACE_LOCAL);
+  return DAG.getNode(NVPTXISD::STACKRESTORE, DL, MVT::Other, {Chain, ASC});
+}
+
+SDValue NVPTXTargetLowering::LowerSTACKSAVE(SDValue Op,
+                                            SelectionDAG &DAG) const {
+  SDLoc DL(Op.getNode());
+  if (STI.getPTXVersion() < 73 || STI.getSmVersion() < 52) {
+    const Function &Fn = DAG.getMachineFunction().getFunction();
+
+    DiagnosticInfoUnsupported NoStackSave(
+        Fn,
+        "Support for stacksave introduced in PTX ISA version 7.3 and "
+        "requires target sm_52.",
----------------
AlexMaclean wrote:

Updated this one as well.

https://github.com/llvm/llvm-project/pull/114484