[flang-commits] [flang] [flang][hlfir] Resolve shape_of users when bufferizing eval_in_mem (PR #201214)

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@@ -638,16 +638,26 @@ tryUsingAssignLhsDirectly(hlfir::EvaluateInMemoryOp evalInMem,
   mlir::Location loc = evalInMem.getLoc();
   hlfir::DestroyOp destroy;
   hlfir::AssignOp assign;
-  for (auto user : llvm::enumerate(evalInMem->getUsers())) {
-    if (user.index() > 2)
+  // A hlfir.shape_of of the result only needs the shape, which the
+  // eval_in_mem already carries as an operand, so it can be redirected to that
+  // operand and does not prevent the in-place rewrite below. Any other user
+  // would dangle when the eval_in_mem is erased, so bail out on it.
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jeanPerier wrote:

nit: rephrase to something like:
"To evaluate directly the hlfir.eval_in_mem into the LHS, the result must only be used in the assignment, in a destroy, and in hlfir.shape_of (which can be replaced by direct use of the shape operand)".

https://github.com/llvm/llvm-project/pull/201214