[Mlir-commits] [mlir] [MLIR] Add single definition multiple regions for mem2reg (PR #89107)

[Christian Ulmann]

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@@ -297,14 +313,52 @@ LogicalResult MemorySlotPromotionAnalyzer::computeBlockingUses(
     }
   }
 
-  // Because this pass currently only supports analysing the parent region of
-  // the slot pointer, if a promotable memory op that needs promotion is outside
-  // of this region, promotion must fail because it will be impossible to
-  // provide a valid `reachingDef` for it.
-  for (auto &[toPromote, _] : userToBlockingUses)
+  // The define uses web only have one definition, It is the potential case.
+  totalStores != 1 ? singleDefining.setPointer(nullptr) : (void)0;
+
+  // The single definition can not dominate all of the uses, there are some
+  // uses need default value and block arguments. But current dominate
+  // frontier algorithms only support single region, so failed.
+  auto leagelSingleDefiningMultiRegions = [this](BlockingUsesMap &userMap) {
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Dinistro wrote:

Nit: Typo in the name.

https://github.com/llvm/llvm-project/pull/89107