[mlir][tensor] Check the EmptyOp's dynamicSize to be non-negative (#65577)

This patch addresses a crash that occurs when negative dynamic sizes are
provided in tensor.emptyOp by adding a check to ensure that dynamic
sizes are non-negative.

Fixes #64064

Author: sott0n

mlir/lib/Dialect/Tensor/IR/TensorOps.cpp

@@ -712,6 +712,9 @@ struct ReplaceEmptyTensorStaticShapeDims : OpRewritePattern<EmptyOp> {
         Value dynamicSize = op.getDynamicSizes()[ctr++];
         std::optional<int64_t> cst = getConstantIntValue(dynamicSize);
         if (cst.has_value()) {
+          // dynamic size must be non-negative.
+          if (cst.value() < 0)
+            return failure();
           staticShape[i] = *cst;
           changedType = true;
         } else {

mlir/test/Dialect/Tensor/canonicalize.mlir

@@ -1848,3 +1848,16 @@ func.func @pack_unpack_dynamic_with_padding(%t: tensor<?x?x?x?xf32>, %dim1: inde
   %packed = tensor.pack %unpacked padding_value(%pad: f32) inner_dims_pos = [0, 1] inner_tiles = [%tile1, %tile2] into %tensor_empty1 : tensor<?x?xf32> -> tensor<?x?x?x?xf32>
   return %packed : tensor<?x?x?x?xf32>
 }
+
+// -----
+
+// CHECK: func.func @invalid_empty_negative_size
+// CHECK: %[[IDX:.*]] = index.constant
+// CHECK: %[[T:.*]] = tensor.empty(%[[IDX]]) : tensor<4x5x?xf32>
+func.func @invalid_empty_negative_size() -> (tensor<4x5x?xf32>) {
+  %c1 = arith.constant 1 : index
+  %cn2 = arith.constant 2 : index
+  %0 = index.sub %c1, %cn2
+  %1 = tensor.empty(%0) : tensor<4x5x?xf32>
+  return %1 : tensor<4x5x?xf32>
+}