Remove unused skip_identities_fn

Author: ricardoV94

pytensor/graph/rewriting/basic.py

@@ -1545,7 +1545,6 @@ def __init__(
         in_pattern,
         out_pattern,
         allow_multiple_clients: bool = False,
-        skip_identities_fn=None,
         name: str | None = None,
         tracks=(),
         get_nodes=None,
@@ -1602,7 +1601,6 @@ def __init__(
             )
         self.__doc__ = f"{self.__class__.__doc__}\n\nThis instance does: {self}\n"
         self.allow_multiple_clients = allow_multiple_clients
-        self.skip_identities_fn = skip_identities_fn
         if name:
             self.__name__ = name
         self._tracks = tracks

pytensor/tensor/rewriting/math.py

@@ -3162,44 +3162,19 @@ def isclose(x, ref, rtol=0, atol=0, num_ulps=10):
     return np.allclose(x, ref, rtol=rtol, atol=atol)
 
 
-def _skip_mul_1(r):
-    if r.owner and r.owner.op == mul:
-        not_is_1 = [i for i in r.owner.inputs if not _is_1(i)]
-        if len(not_is_1) == 1:
-            return not_is_1[0]
-
-
-def _is_1(expr):
-    """
-
-    Returns
-    -------
-    bool
-        True iff expr is a constant close to 1.
-
-    """
-    try:
-        v = get_underlying_scalar_constant_value(expr)
-        return isclose(v, 1)
-    except NotScalarConstantError:
-        return False
-
-
 logsigm_to_softplus = PatternNodeRewriter(
     (log, (sigmoid, "x")),
     (neg, (softplus, (neg, "x"))),
     allow_multiple_clients=True,
     values_eq_approx=values_eq_approx_remove_inf,
-    skip_identities_fn=_skip_mul_1,
     tracks=[sigmoid],
     get_nodes=get_clients_at_depth1,
 )
 log1msigm_to_softplus = PatternNodeRewriter(
-    (log, (sub, dict(pattern="y", constraint=_is_1), (sigmoid, "x"))),
+    (log, (sub, 1, (sigmoid, "x"))),
     (neg, (softplus, "x")),
     allow_multiple_clients=True,
     values_eq_approx=values_eq_approx_remove_inf,
-    skip_identities_fn=_skip_mul_1,
     tracks=[sigmoid],
     get_nodes=get_clients_at_depth2,
 )
@@ -3396,10 +3371,8 @@ def local_exp_over_1_plus_exp(fgraph, node):
 
     if len(denom_rest) == 0:
         return [new_num]
-    elif len(denom_rest) == 1:
-        out = new_num / denom_rest[0]
     else:
-        out = new_num / mul(*denom_rest)
+        out = new_num / variadic_mul(*denom_rest)
 
     copy_stack_trace(node.outputs[0], out)
     return [out]
@@ -3769,7 +3742,7 @@ def local_reciprocal_1_plus_exp(fgraph, node):
 
 # 1 - sigmoid(x) -> sigmoid(-x)
 local_1msigmoid = PatternNodeRewriter(
-    (sub, dict(pattern="y", constraint=_is_1), (sigmoid, "x")),
+    (sub, 1, (sigmoid, "x")),
     (sigmoid, (neg, "x")),
     tracks=[sigmoid],
     get_nodes=get_clients_at_depth1,