Support matching Args for SubgraphMatcher (#85456)

Subgraph matcher now handles the matching of non-Node arguments.

Here are the 4 cases
- pn is Node, gn is Node: this go through the regular _match_node() function
- pn is Noed, gn is not a Node: this is a match if only pn is a placeholder op
- pn is not Node, gn is Node: this is a no match case
- pn is not a Node, gn is not a Node: this will go through the argument comparison.

With this change
```
def target(x):
    return foo(x, 3)

def pattern(x, y):
    return foo(x, y)
```

is a match

Pull Request resolved: https://github.com/pytorch/pytorch/pull/85456
Approved by: https://github.com/jerryzh168

test/test_fx_passes.py

@@ -621,6 +621,49 @@ class MultiOutputWithWithInvalidMatches:
         TestCase(False, True, 0),
     ]
 
+class QuantizationFp8Pattern:
+    @classmethod
+    def setup(cls):
+        cls.quantization = torch.library.Library("fp8_quantization", "DEF")
+        cls.quantization.define("quantize_per_tensor_affine_fp8(Tensor self, int dtype, float scale) -> Tensor")
+        cls.quantization.define("dequantize_per_tensor_affine_fp8(Tensor self, int dtype, float scale) -> Tensor")
+
+    @classmethod
+    def tearDown(cls):
+        del cls.quantization
+
+    @staticmethod
+    def forward(self, arg0_1, arg1_1):
+        qt = torch.ops.fp8_quantization
+        _scale_0 = self._scale_0
+        quantize_per_tensor_affine_fp8 = qt.quantize_per_tensor_affine_fp8(arg0_1, 0, _scale_0)
+        dequantize_per_tensor_affine_fp8 = qt.dequantize_per_tensor_affine_fp8(quantize_per_tensor_affine_fp8, 0, _scale_0)
+        _scale_1 = self._scale_0
+        quantize_per_tensor_affine_fp8_1 = qt.quantize_per_tensor_affine_fp8(arg1_1, 0, _scale_1)
+        dequantize_per_tensor_affine_fp8_1 = qt.dequantize_per_tensor_affine_fp8(quantize_per_tensor_affine_fp8_1, 0, _scale_1)
+        add = torch.ops.aten.add.Tensor(dequantize_per_tensor_affine_fp8, dequantize_per_tensor_affine_fp8_1)
+        _scale_2 = self._scale_0
+        quantize_per_tensor_affine_fp8_2 = qt.quantize_per_tensor_affine_fp8(add, 0, _scale_2)
+        dequantize_per_tensor_affine_fp8_2 = qt.dequantize_per_tensor_affine_fp8(quantize_per_tensor_affine_fp8_2, 0, _scale_2)
+        return dequantize_per_tensor_affine_fp8_2
+
+    @staticmethod
+    def pattern(a, a_dtype, a_scale, b, b_dtype, b_scale, out_scale):
+        qt = torch.ops.fp8_quantization
+        a = qt.dequantize_per_tensor_affine_fp8(a, a_dtype, a_scale)
+        b = qt.dequantize_per_tensor_affine_fp8(b, b_dtype, b_scale)
+        output = torch.ops.aten.add.Tensor(a, b)
+
+        qt.dequantize_per_tensor_affine_fp8
+
+        output = qt.quantize_per_tensor_affine_fp8(output, a_dtype, out_scale)
+        return output
+
+    test_cases = [
+        # match_output, match_placeholder, num_matches
+        TestCase(False, False, 1),
+    ]
+
 @instantiate_parametrized_tests
 class TestFXMatcherUtils(JitTestCase):
 
@@ -639,8 +682,14 @@ class TestFXMatcherUtils(JitTestCase):
         MultipleOutputsIdenticalAnchor,
         MultipleOutputsHorizontalPattern,
         MultiOutputWithWithInvalidMatches,
+        QuantizationFp8Pattern,
     ])
     def test_subgraph_matcher(self, test_model):
+
+        setup = getattr(test_model, "setup", None)
+        if callable(setup):
+            setup()
+
         traced = symbolic_trace(test_model.forward)
         pattern_traced = symbolic_trace(test_model.pattern)
 
@@ -662,6 +711,10 @@ class TestFXMatcherUtils(JitTestCase):
                         continue
                     assert node in match.nodes_map
 
+        tearDown = getattr(test_model, "tearDown", None)
+        if callable(setup):
+            tearDown()
+
 
 if __name__ == "__main__":
     run_tests()

torch/fx/passes/utils/matcher_utils.py

@@ -4,7 +4,8 @@ import copy
 from torch.fx.graph import Graph
 from torch.fx.node import Node
 from torch.fx._compatibility import compatibility
-from typing import Dict, List, Set
+import torch.utils._pytree as pytree
+from typing import Dict, List, Set, Any
 
 __all__ = ['SubgraphMatcher', 'InternalMatch']
 
@@ -124,7 +125,27 @@ class SubgraphMatcher:
                         nodes_matched.add(gn)
         return non_overlapping_matches
 
+    def _match_args(self, pn: Any, gn: Any, match: InternalMatch) -> bool:
+        assert not(isinstance(pn, Node) and isinstance(gn, Node)), "pn and gn cannot both be Node"
+
+        if isinstance(pn, Node) and not isinstance(gn, Node):
+            if pn.op == "placeholder":
+                # Check if we've already matched these nodes in the current
+                # traversal
+                if pn in match.nodes_map:
+                    return match.nodes_map[pn] == gn
+
+                match.nodes_map[pn] = gn
+                return True
+            else:
+                return False
+        elif not isinstance(pn, Node) and isinstance(gn, Node):
+            return False
+        else:
+            return type(gn) == type(pn) and gn == pn
+
     def _match_nodes(self, pn: Node, gn: Node, match: InternalMatch) -> bool:
+        assert isinstance(pn, Node) and isinstance(gn, Node), "pn and gn must be Node"
 
         # Check if we've already matched these nodes in the current
         # traversal
@@ -146,9 +167,23 @@ class SubgraphMatcher:
 
         # Recursively traverse upwards to check if `pn` is a true
         # match for `gn`
-        match_found = (len(pn.all_input_nodes) == len(gn.all_input_nodes) and
-                       all(self._match_nodes(pn_, gn_, match) for pn_, gn_
-                           in zip(pn.all_input_nodes, gn.all_input_nodes)))
+        match_found = True
+
+        pn_flatten_args, _ = pytree.tree_flatten(pn.args)
+        gn_flatten_args, _ = pytree.tree_flatten(gn.args)
+
+        if len(pn_flatten_args) == len(gn_flatten_args):
+            for pn_, gn_ in zip(pn_flatten_args, gn_flatten_args):
+                if isinstance(gn_, Node) and isinstance(pn_, Node):
+                    matched = self._match_nodes(pn_, gn_, match)
+                else:
+                    matched = self._match_args(pn_, gn_, match)
+
+                if not matched:
+                    match_found = False
+                    break
+        else:
+            match_found = False
 
         if not match_found:
             match.nodes_map.pop(pn)