[Mlir-commits] [mlir] [MLIR][Vector]Generalize DropUnitDimFromElementwiseOps (PR #92934)

[Han-Chung Wang]

================
@@ -1652,42 +1672,29 @@ struct DropUnitDimFromElementwiseOps final
     // guaranteed to have identical shapes (with some exceptions such as
     // `arith.select`) and it suffices to only check one of them.
     auto sourceVectorType = dyn_cast<VectorType>(op->getOperand(0).getType());
-    if (!sourceVectorType)
-      return failure();
-    if (sourceVectorType.getRank() < 2)
+    if (!sourceVectorType || sourceVectorType.getRank() < 2)
       return failure();
 
-    bool hasTrailingDimUnitFixed =
-        ((sourceVectorType.getShape().back() == 1) &&
-         (!sourceVectorType.getScalableDims().back()));
-    bool hasLeadingDimUnitFixed =
-        ((sourceVectorType.getShape().front() == 1) &&
-         (!sourceVectorType.getScalableDims().front()));
-    if (!hasLeadingDimUnitFixed && !hasTrailingDimUnitFixed)
-      return failure();
-
-    // Drop leading/trailing unit dim by applying vector.shape_cast to all
-    // operands
-    int64_t dim = hasLeadingDimUnitFixed ? 0 : sourceVectorType.getRank() - 1;
-
     SmallVector<Value> newOperands;
     auto loc = op->getLoc();
     for (auto operand : op->getOperands()) {
       auto opVectorType = cast<VectorType>(operand.getType());
-      VectorType newVType = VectorType::Builder(opVectorType).dropDim(dim);
+      auto newVType = dropNonScalableUnitDimFromType(opVectorType);
+      if (newVType == opVectorType)
+        return rewriter.notifyMatchFailure(op, "No unit dimension to remove.");
+
       auto opSC = rewriter.create<vector::ShapeCastOp>(loc, newVType, operand);
       newOperands.push_back(opSC);
     }
 
     VectorType newResultVectorType =
-        VectorType::Builder(resultVectorType).dropDim(dim);
-    // Create an updated elementwise Op without leading/trailing unit dim
+        dropNonScalableUnitDimFromType(resultVectorType);
+    // Create an updated elementwise Op without unit dim
     Operation *elementwiseOp =
         rewriter.create(loc, op->getName().getIdentifier(), newOperands,
                         newResultVectorType, op->getAttrs());
 
-    // Restore the leading/trailing unit dim by applying vector.shape_cast
-    // to the result
+    // Restore the unit dim by applying vector.shape_cast to the result
----------------
hanhanW wrote:

nit: add `.` to the end of the comment to complete the sentence. 

https://github.com/llvm/llvm-project/pull/92934