[RFC][GlobalISel] Allow match against iPTR operand in leaf node

[lkail]

Summary

When using MVTToLLT to check corresponding LLT, also allow iPTR to pass the check. Thus we can import more patterns like ComplexPattern<iPTR, ...> in SDAG.

[lkail]

Ping.

[shchenz]

llvm/utils/TableGen/GlobalISelEmitter.cpp

4607

Can you show an imported rule with ptr type in GISel's MatchTable after this change? I don't think GIM_CheckType can check a pointer type for now?

[aemerson]

Also, any tests?

[arsenm]

Test would be nice

llvm/utils/TableGen/GlobalISelEmitter.cpp

Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderer(
   if (auto *ChildDefInit = dyn_cast<DefInit>(DstChild->getLeafValue())) {
     auto *ChildRec = ChildDefInit->getDef();
 
     ArrayRef<TypeSetByHwMode> ChildTypes = DstChild->getExtTypes();
     if (ChildTypes.size() != 1)
       return failedImport("Dst pattern child has multiple results");
 
     std::optional<LLTCodeGen> OpTyOrNone;
-    if (ChildTypes.front().isMachineValueType())
-      OpTyOrNone = MVTToLLT(ChildTypes.front().getMachineValueType().SimpleTy);
+    if (ChildTypes.front().isMachineValueType()) {
+      MVT VT = ChildTypes.front().getMachineValueType();
+      // Allow import more patterns like ComplexPattern<iPTR, ..>.
+      if (VT == MVT::iPTR)
+        // Since we don't know the exact pointer size for target supporting
+        // multiple address modes when tables are generated, no LLT is passed
+        // into LLTCodeGen.
+        OpTyOrNone = LLTCodeGen();
+      else
+        OpTyOrNone = MVTToLLT(VT.SimpleTy);
+    }
     if (!OpTyOrNone)
       return failedImport("Dst operand has an unsupported type");
 
     if (ChildRec->isSubClassOf("Register")) {
       DstMIBuilder.addRenderer<AddRegisterRenderer>(Target, ChildRec);
       return InsertPt;
     }