Update ll_builder.py

Author: BobTheBuidler

mypyc/irbuild/ll_builder.py

@@ -1554,6 +1554,7 @@ def compare_strings(self, lhs: Value, rhs: Value, op: str, line: int) -> Value:
         """Compare two strings"""
         if op == "==":
             # We can specialize this case if one or both values are string literals
+            literal_fastpath = False
 
             def is_string_literal(value: Value) -> TypeGuard[LoadLiteral]:
                 return isinstance(value, LoadLiteral) and is_str_rprimitive(value.type)
@@ -1562,11 +1563,18 @@ def is_string_literal(value: Value) -> TypeGuard[LoadLiteral]:
                 if is_string_literal(rhs):
                     # we can optimize out the check entirely in some constant-folded cases
                     return self.true() if lhs.value == rhs.value else self.false()
-                literal_length = Integer(len(lhs.value), c_pyssize_t_rprimitive, line)  # type: ignore [arg-type]
-                return self.primitive_op(str_eq_literal, [rhs, lhs, literal_length], line)
+                
+                # if lhs argument is string literal, switch sides to match specializer C api
+                lhs, rhs = rhs, lhs
+                literal_fastpath = True
             elif is_string_literal(rhs):
-                literal_length = Integer(len(rhs.value), c_pyssize_t_rprimitive, line)  # type: ignore [arg-type]
+                literal_fastpath = True
+                
+            if literal_fastpath:
+                literal_string = cast(str, cast(LoadLiteral, rhs).value)
+                literal_length = Integer(len(literal_string), c_pyssize_t_rprimitive, line)
                 return self.primitive_op(str_eq_literal, [lhs, rhs, literal_length], line)
+            
             return self.primitive_op(str_eq, [lhs, rhs], line)
 
         elif op == "!=":