[Inductor][CPP] Fix node name for wgt delete (pytorch#147056)

**Summary**
This is a regression issue caused by a change in the FX node name. In commit 71010bf, both the node name and target for the `get_attr` node in `V.graph.graph.nodes` were `_frozen_param2`. However, in the latest main, the node name has changed to `_reorder_linear_weight`. This PR fixes the regression by using the node's target instead of its name.

**Test Plan**
```
python -u -m pytest -s -v test/inductor/test_cpu_select_algorithm.py -k test_cpp_weight_prune
```

Pull Request resolved: pytorch#147056
Approved by: https://github.com/jgong5

test/inductor/test_cpu_select_algorithm.py

@@ -2051,6 +2051,29 @@ def forward(self, x):
             self.common(mod, (v,), atol=atol, rtol=rtol)
             self.assertEqual(counters["inductor"]["select_algorithm_autotune"], 1)
 
+    @inductor_config.patch({"freezing": True})
+    @patches
+    @torch.no_grad
+    @unittest.skipIf(not TEST_MKL, "Test requires MKL")
+    def test_cpp_weight_prune(self):
+        class M(torch.nn.Module):
+            def __init__(self):
+                super().__init__()
+                self.linear = torch.nn.Linear(32, 128, bias=False)
+
+            def forward(self, x):
+                return self.linear(x)
+
+        v = torch.randn(2, 32).to(torch.bfloat16)
+        mod = M().eval().to(torch.bfloat16)
+        torch._dynamo.reset()
+        torch._inductor.metrics.reset()
+        counters.clear()
+        with verify(torch.bfloat16) as (atol, rtol):
+            self.common(mod, (v,), atol=atol, rtol=rtol)
+        self.assertEqual(counters["inductor"]["select_algorithm_autotune"], 1)
+        self.assertEqual(counters["inductor"]["select_algorithm_weight_prune"], 1)
+
     @patches
     @torch.no_grad
     @unittest.skipIf(not TEST_MKL, "Test requires MKL")

torch/_inductor/codegen/cpp_gemm_template.py

@@ -383,9 +383,9 @@ def get_candidates(input_nodes, new_input_nodes):
             # Case may happen when the candidate tensor is used by more than 1 get_attr node
             # https://github.com/pytorch/pytorch/issues/134998
             if node.op == "get_attr" and hasattr(
-                V.graph.module, node.name
+                V.graph.module, node.target
             ):  # candidate tensor might already be deleted
-                comp_tensor = getattr(V.graph.module, node.name)
+                comp_tensor = getattr(V.graph.module, node.target)
                 if isinstance(comp_tensor, torch.Tensor) and share_storage(
                     candidate_tensor, comp_tensor
                 ):
@@ -395,13 +395,15 @@ def get_candidates(input_nodes, new_input_nodes):
             # The get_attr node has only 1 user fx node
             # The candidate tensor has been used by only 1 get_attr node
             if (
-                node.name == candidate_node.get_name()
+                node.op == "get_attr"
+                and node.target == candidate_node.get_name()
                 and len(node.users) == 1
                 and candidate_tensor_users == 1
             ):
-                del V.graph.constants[node.name]
-                delattr(V.graph.module, node.name)
-                delattr(V.graph.graph.owning_module, node.name)
+                del V.graph.constants[node.target]
+                delattr(V.graph.module, node.target)
+                delattr(V.graph.graph.owning_module, node.target)
+                counters["inductor"]["select_algorithm_weight_prune"] += 1
 
 
 def gen_2d_view_of_epilogue_buf(