[Mlir-commits] [mlir] [mlir][acc] Add LegalizeDataValues support for DeclareEnterOp (PR #138008)

[Razvan Lupusoru]

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@@ -71,7 +72,54 @@ static void replaceAllUsesInAccComputeRegionsWith(Value orig, Value replacement,
 }
 
 template <typename Op>
-static void collectAndReplaceInRegion(Op &op, bool hostToDevice) {
+static void replaceAllUsesInUnstructuredComputeRegionWith(
+    Op &op, llvm::SmallVector<std::pair<Value, Value>> &values,
+    DominanceInfo &domInfo, PostDominanceInfo &postDomInfo) {
+
+  Operation *exitOp = op.getOperation();
+  if constexpr (std::is_same_v<Op, acc::DeclareEnterOp>) {
+    // For declare enter/exit pairs, verify there is exactly one exit op using
+    // the token
+    if (!op.getToken().hasOneUse())
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razvanlupusoru wrote:

This is too restrictive since from a language perspective multiple exits are allowed - and a dialect may choose to permit that. I think the algorithm here should collect all of the `declare_exit`'s and ensure that the replaced use post-dominates one of them.

https://github.com/llvm/llvm-project/pull/138008