Remove `warn__identify_1pexp_bug` flag

aesara/configdefaults.py

@@ -1436,14 +1436,6 @@ def add_deprecated_configvars():
         in_c_key=False,
     )
 
-    # TODO: remove?
-    config.add(
-        "warn__identify_1pexp_bug",
-        "Warn if Aesara versions prior to 7987b51 (2011-12-18) could have "
-        "yielded a wrong result due to a bug in the is_1pexp function",
-        BoolParam(_warn_default("0.4.1")),
-        in_c_key=False,
-    )
     # TODO: this setting is not used anywhere
     config.add(
         "gpu__local_elemwise_fusion",

aesara/tensor/math_opt.py

@@ -3068,19 +3068,6 @@ def is_1pexp(t, only_process_constants=True):
                         scal_sum = scal_sum + s
                     if np.allclose(scal_sum, 1):
                         return False, maybe_exp.owner.inputs[0]
-                # Before 7987b51 there used to be a bug where *any* constant
-                # was considered as if it was equal to 1, and thus this
-                # function would incorrectly identify it as (1 + exp(x)).
-                if config.warn__identify_1pexp_bug:
-                    warnings.warn(
-                        "Although your current code is fine, please note that "
-                        "Aesara versions prior to 0.5 (more specifically, "
-                        "prior to commit 7987b51 on 2011-12-18) may have "
-                        "yielded an incorrect result. To remove this warning, "
-                        "either set the `warn__identify_1pexp_bug` config "
-                        "option to False, or `warn__ignore_bug_before` to at "
-                        "least '0.4.1'."
-                    )
     return None
 
 

tests/tensor/test_math_opt.py

@@ -4074,9 +4074,6 @@ class TestSigmoidOpts:
         x = vector()
         data = np.random.random((54)).astype(config.floatX)
 
-        backup = config.warn__identify_1pexp_bug
-        config.warn__identify_1pexp_bug = False
-        try:
         # tests exp_over_1_plus_exp
         f = aesara.function([x], exp(x) / (1 + exp(x)), mode=m)
         assert [node.op for node in f.maker.fgraph.toposort()] == [sigmoid]
@@ -4205,10 +4202,6 @@ class TestSigmoidOpts:
         ]
         f(data)
 
-        finally:
-            # Restore config option.
-            config.warn__identify_1pexp_bug = backup
-
     def test_local_1msigmoid(self):
         m = self.get_mode(excluding=["fusion", "inplace"])
         x = fmatrix()
@@ -4465,9 +4458,6 @@ class TestSigmoidUtils:
         ]
 
     def test_is_1pexp(self):
-        backup = config.warn__identify_1pexp_bug
-        config.warn__identify_1pexp_bug = False
-        try:
         x = vector("x")
         exp_op = exp
         assert is_1pexp(1 + exp_op(x), False) == (False, x)
@@ -4483,8 +4473,6 @@ class TestSigmoidUtils:
         assert is_1pexp(exp_op(x) - 1, False) is None
         assert is_1pexp(-1 + exp_op(x), False) is None
         assert is_1pexp(1 + 2 * exp_op(x), False) is None
-        finally:
-            config.warn__identify_1pexp_bug = backup
 
 
 def test_log1mexp_stabilization():