[Mlir-commits] [mlir] [mlir][vector] Teach `TransferOptimization` to look through trivial aliases (PR #87805)

[Diego Caballero]

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@@ -88,6 +88,46 @@ bool TransferOptimization::isReachable(Operation *start, Operation *dest) {
   return false;
 }
 
+/// Walk up the source chain until an operation that changes/defines the view of
+/// memory is found (i.e. skip operations that alias the entire view).
+Value skipFullyAliasingOperations(Value source) {
+  while (auto op = source.getDefiningOp()) {
+    if (auto subViewOp = dyn_cast<memref::SubViewOp>(op);
+        subViewOp && subViewOp.hasZeroOffset() && subViewOp.hasUnitStride()) {
+      // A `memref.subview` with an all zero offset, and all unit strides, still
+      // points to the same memory.
+      source = subViewOp.getSource();
+    } else if (auto castOp = dyn_cast<memref::CastOp>(op)) {
+      // A `memref.cast` still points to the same memory.
+      source = castOp.getSource();
+    } else {
+      return source;
+    }
+  }
+  return source;
+}
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dcaballe wrote:

I wonder if these "aliasing" utilities could be generally helpful and we should move them to a public header with other utilities...

https://github.com/llvm/llvm-project/pull/87805