[CINN] Fix reduce fusion without reduce axis reuse

paddle/cinn/operator_fusion/policy/relative_judge_policy.cc

@@ -218,9 +218,24 @@ bool RelativeJudgePolicy::ReduceTreeGrownCanMerge(
   }
   const auto& [related, _UNUSED] =
       SplitFirstIfRelatedBySecond(downstream_reduce_dims, upstream_output_dims);
-  auto res = (related.size() == 0);
-  VLOG(4) << "ReduceTreeGrownCanMerge: " << res;
-  return res;
+  if (related.size() > 0) {
+    return false;
+  }
+
+  auto upstream_reduce_op = upstream_tree.GetRootPattern().GetReduceOp();
+  const auto& [upstream_reduce_dims, _unused_dims] = SplitReduceDims(
+      axes_info_.GetSignature(upstream_reduce_op), upstream_reduce_op);
+  if (upstream_reduce_dims.size() != downstream_reduce_dims.size()) {
+    return false;
+  }
+  for (size_t i = 0; i < upstream_reduce_dims.size(); ++i) {
+    if (upstream_reduce_dims[i].GetSymbolicDim() !=
+        downstream_reduce_dims[i].GetSymbolicDim()) {
+      return false;
+    }
+  }
+
+  return true;
 }
 
 bool RelativeJudgePolicy::ReducePlusTrivialCanMerge(

test/ir/pir/cinn/test_reduce_fusion.py

@@ -105,6 +105,31 @@ def init():
 
         self.compare_result(func, None, init)
 
+    def test_reduce_fusion_without_axis_reuse(self):
+        #     R
+        #    / \
+        #   T   T
+        #    \ /
+        #     T
+        #     |
+        #     B
+        #     |
+        #     R
+        def func(x):
+            b = paddle.max(x, axis=-1)
+            c = b * 2
+            d = b / 2
+            e = c + d
+            f = paddle.expand(e, [96, 32, 32])
+            g = paddle.sum(f, axis=0)
+            return g
+
+        def init():
+            x = paddle.rand((32, 32, 128))
+            return (x,)
+
+        self.compare_result(func, None, init)
+
 
 if __name__ == "__main__":
     unittest.main()