1 files changed, 17 insertions, 15 deletions
diff --git a/sqlglot/optimizer/simplify.py b/sqlglot/optimizer/simplify.py
index 0904189..e2772a0 100644
--- a/sqlglot/optimizer/simplify.py
+++ b/sqlglot/optimizer/simplify.py
@@ -5,11 +5,9 @@ from collections import deque
 from decimal import Decimal
 
 from sqlglot import exp
-from sqlglot.generator import Generator
+from sqlglot.generator import cached_generator
 from sqlglot.helper import first, while_changing
 
-GENERATOR = Generator(normalize=True, identify="safe")
-
 
 def simplify(expression):
     """
@@ -27,12 +25,12 @@ def simplify(expression):
         sqlglot.Expression: simplified expression
     """
 
-    cache = {}
+    generate = cached_generator()
 
     def _simplify(expression, root=True):
         node = expression
         node = rewrite_between(node)
-        node = uniq_sort(node, cache, root)
+        node = uniq_sort(node, generate, root)
         node = absorb_and_eliminate(node, root)
         exp.replace_children(node, lambda e: _simplify(e, False))
         node = simplify_not(node)
@@ -247,7 +245,7 @@ def remove_compliments(expression, root=True):
     return expression
 
 
-def uniq_sort(expression, cache=None, root=True):
+def uniq_sort(expression, generate, root=True):
     """
     Uniq and sort a connector.
 
@@ -256,7 +254,7 @@ def uniq_sort(expression, cache=None, root=True):
     if isinstance(expression, exp.Connector) and (root or not expression.same_parent):
         result_func = exp.and_ if isinstance(expression, exp.And) else exp.or_
         flattened = tuple(expression.flatten())
-        deduped = {GENERATOR.generate(e, cache): e for e in flattened}
+        deduped = {generate(e): e for e in flattened}
         arr = tuple(deduped.items())
 
         # check if the operands are already sorted, if not sort them
@@ -388,14 +386,18 @@ def _simplify_binary(expression, a, b):
 
 
 def simplify_parens(expression):
-    if (
-        isinstance(expression, exp.Paren)
-        and not isinstance(expression.this, exp.Select)
-        and (
-            not isinstance(expression.parent, (exp.Condition, exp.Binary))
-            or isinstance(expression.this, exp.Predicate)
-            or not isinstance(expression.this, exp.Binary)
-        )
+    if not isinstance(expression, exp.Paren):
+        return expression
+
+    this = expression.this
+    parent = expression.parent
+
+    if not isinstance(this, exp.Select) and (
+        not isinstance(parent, (exp.Condition, exp.Binary))
+        or isinstance(this, exp.Predicate)
+        or not isinstance(this, exp.Binary)
+        or (isinstance(this, exp.Add) and isinstance(parent, exp.Add))
+        or (isinstance(this, exp.Mul) and isinstance(parent, exp.Mul))
     ):
         return expression.this
     return expression