fix expand_as (#66311)

Author: zyfncg

paddle/fluid/pir/dialect/operator/interface/infer_symbolic_shape/binary_infer_sym.cc

@@ -215,6 +215,10 @@ bool ExpandAsOpInferSymbolicShape(
   std::vector<int> target_shape =
       paddle::dialect::details::GetVectorAttr<int>(op, "target_shape");
   const std::vector<symbol::DimExpr> &output_dims = [&] {
+    if (op->operand_source(0)) {
+      return infer_context->GetShapeOrDataForValue(op->operand_source(1))
+          .shape();
+    }
     std::vector<symbol::DimExpr> output_dims;
     output_dims.reserve(target_shape.size());
     for (int shape : target_shape) {

python/paddle/tensor/manipulation.py

@@ -4447,7 +4447,7 @@ def expand_as(x: Tensor, y: Tensor, name: str | None = None) -> Tensor:
                 "some_var.stop_gradient = True, supporting "
                 "some_var as the input 'x'."
             )
-        return _C_ops.expand_as(x, None, y.shape)
+        return _C_ops.expand_as(x, y, y.shape)
     else:
         check_variable_and_dtype(
             x,