Introduce pattern.any_value (#2175)

Introduce pattern.any_value as a convenience when writing patterns. It
is more precise than using `_allow_other_inputs=True` (which will allow
any number of inputs).

Author: gramalingam

onnxscript/rewriter/ort_fusions/gqa.py

@@ -87,19 +87,17 @@ def pattern(
         shape_B111,
     ):
         # Reshape query from (B, S, D) to (B, S, H, D/H)
-        query_BSHDh = op.Reshape(query_BSD, _allow_other_inputs=True, _outputs=["query_BSHDh"])
+        query_BSHDh = op.Reshape(query_BSD, pattern.ANY_VALUE, _outputs=["query_BSHDh"])
         # Transpose from (B, S, H, D/H) to (B, H, S, D/H)
         query_BHSDh = op.Transpose(query_BSHDh, perm=[0, 2, 1, 3])
 
         # Reshape key from (B, S, Dkv) to (B, S, Hkv, D/H)
-        key_BSHkvDh = op.Reshape(key_BSDkv, _allow_other_inputs=True, _outputs=["key_BSHkvDh"])
+        key_BSHkvDh = op.Reshape(key_BSDkv, pattern.ANY_VALUE, _outputs=["key_BSHkvDh"])
         # Transpose from (B, S, Hkv, D/H) to (B, Hkv, S, D/H)
         key_BHkvSDh = op.Transpose(key_BSHkvDh, perm=[0, 2, 1, 3])
 
         # Reshape value from (B, S, Dkv) to (B, S, Hkv, D/H)
-        value_BSHkvDh = op.Reshape(
-            value_BSDkv, _allow_other_inputs=True, _outputs=["value_BSHkvDh"]
-        )
+        value_BSHkvDh = op.Reshape(value_BSDkv, pattern.ANY_VALUE, _outputs=["value_BSHkvDh"])
         # Transpose from (B, S, Hkv, D/H) to (B, Hkv, S, D/H)
         value_BHkvSDh = op.Transpose(value_BSHkvDh, perm=[0, 2, 1, 3])
 
@@ -129,18 +127,18 @@ def pattern(
 
         key_seq_BHkvTDh = op.Concat(past_key, key_BHkvSDh_rope, axis=-2)
         key_seq_BHkv1TDh = op.Unsqueeze(key_seq_BHkvTDh, 2)
-        key_seq_BHkvGTDh = op.Expand(key_seq_BHkv1TDh, _allow_other_inputs=True)
+        key_seq_BHkvGTDh = op.Expand(key_seq_BHkv1TDh, pattern.ANY_VALUE)
         key_seq_BHTDh = op.Reshape(
-            key_seq_BHkvGTDh, _allow_other_inputs=True, _outputs=["key_seq_BHTDh"]
+            key_seq_BHkvGTDh, pattern.ANY_VALUE, _outputs=["key_seq_BHTDh"]
         )
 
         # Concatenate past_value cache and current value, expand across heads
         # that share key/value.
         value_seq_BHkvTDh = op.Concat(past_value, value_BHkvSDh, axis=-2)
         value_seq_BHkv1TDh = op.Unsqueeze(value_seq_BHkvTDh, 2)
-        value_seq_BHkvGTDh = op.Expand(value_seq_BHkv1TDh, _allow_other_inputs=True)
+        value_seq_BHkvGTDh = op.Expand(value_seq_BHkv1TDh, pattern.ANY_VALUE)
         value_seq_BHTDh = op.Reshape(
-            value_seq_BHkvGTDh, _allow_other_inputs=True, _outputs=["value_seq_BHTDh"]
+            value_seq_BHkvGTDh, pattern.ANY_VALUE, _outputs=["value_seq_BHTDh"]
         )
 
         mask = causal_mask_pattern(op, input_ids, some_kv_cache, shape_B111)
@@ -158,7 +156,7 @@ def pattern(
         attention_BSHDh = op.Transpose(attention_BHSDh, perm=[0, 2, 1, 3])
         # Reshape back to (B, S, D)
         attention_BSD = op.Reshape(
-            attention_BSHDh, _allow_other_inputs=True, _outputs=["attention_BSD"]
+            attention_BSHDh, pattern.ANY_VALUE, _outputs=["attention_BSD"]
         )
         return attention_BSD, key_seq_BHkvTDh, value_seq_BHkvTDh
 

onnxscript/rewriter/pattern.py

@@ -634,6 +634,20 @@ def _is_pattern_variable(x: Any) -> bool:
     return type(x) is ValuePattern
 
 
+class AnyValue(ValuePattern):
+    """Represents a pattern that matches against any value."""
+
+    def __init__(self) -> None:
+        super().__init__(None)
+
+    def clone(self, node_map: dict[NodePattern, NodePattern]) -> AnyValue:
+        # A single instance of AnyValue suffices.
+        return self
+
+
+ANY_VALUE = AnyValue()
+
+
 class Constant(ValuePattern):
     """Represents a pattern that matches against a scalar constant value."""
 
@@ -1108,6 +1122,9 @@ def _bind_value(self, pattern_value: ValuePattern, value: ir.Value | None) -> bo
 
     def _match_value(self, pattern_value: ValuePattern, value: ir.Value | None) -> bool:
         """Match an IR value against a ValuePattern instance."""
+        if isinstance(pattern_value, AnyValue):
+            return True
+
         if not self._bind_value(pattern_value, value):
             return False
 

onnxscript/rewriter/pattern_test.py

@@ -667,6 +667,27 @@ def test_model(x: FLOAT[1024], y: FLOAT[1024], z: FLOAT[1024]) -> FLOAT[1024]:
         onnxscript.optimizer.inline(model)
         self.assertEqual([x.op_type for x in model.graph], ["Add", "Mul", "Add", "Mul"])
 
+    def test_any_value(self):
+        def source_pattern(op, x):
+            return op.Add(x, op.Mul(0, pattern.ANY_VALUE))
+
+        def replacement(op, x):
+            return op.Identity(x)
+
+        rule = pattern.RewriteRule(source_pattern, replacement)
+
+        @script()
+        def test_model(x: FLOAT[1024], y: FLOAT[1024]) -> FLOAT[1024]:
+            zero = op.Constant(value_float=0.0)
+            return op.Add(x, op.Mul(zero, y))
+
+        model_proto = test_model.to_model_proto()
+        model = ir.serde.deserialize_model(model_proto)
+        self.assertEqual([x.op_type for x in model.graph], ["Constant", "Mul", "Add"])
+        rule.apply_to_model(model)
+        self.assertEqual(len(model.graph), 2)
+        self.assertEqual([x.op_type for x in model.graph], ["Constant", "Identity"])
+
 
 class PatternBuilderTest(unittest.TestCase):
     def test_pattern_builder_context(self):