[llvm] [DirectX] Add Resource uses to Resource Handle map in DXILResourceMap (PR #112798)

[Helena Kotas via llvm-commits]

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@@ -744,6 +750,23 @@ DXILResourceMap::DXILResourceMap(
   }
 }
 
+void DXILResourceMap::updateResourceMap(CallInst *origCallInst,
+                                        CallInst *newCallInst) {
+  assert((origCallInst != nullptr) && (newCallInst != nullptr) &&
+         (origCallInst != newCallInst));
+
+  CallMap.try_emplace(newCallInst, CallMap[origCallInst]);
+  CallMap.erase(origCallInst);
+
+  // Update ResUseToHandleMap since Resource Handle changed
+  for (auto it = origCallInst->users().begin();
+       it != origCallInst->users().end();
+       ++it) {
+    CallInst *CI_Use = dyn_cast<CallInst>(*it);
+    ResUseToHandleMap[CI_Use] = newCallInst;
+  }
----------------
hekota wrote:

This is a bit confusing. You are removing `origCallInst` from `CallMap`, and then iterating over its uses and remapping them the `newCallInst`. Are you doing it this way because after `replaceAllUsesWith` the `newCallInst` uses will be the temporary handle casts? It might be worth adding an explaining comment. And maybe an assert checking that `newCallInst` does nor not have any uses yet when `updateResourceMap` is called.


https://github.com/llvm/llvm-project/pull/112798