Added performance test #1665.

dbms/tests/performance/float_parsing/float_parsing.xml

+<test>
+    <name>float_parsing</name>
+    <type>once</type>
+    <tags>
+        <tag>long</tag>
+    </tags>
+
+    <stop_conditions>
+        <all_of>
+            <total_time_ms>10000</total_time_ms>
+        </all_of>
+        <any_of>
+            <average_speed_not_changing_for_ms>5000</average_speed_not_changing_for_ms>
+            <total_time_ms>20000</total_time_ms>
+        </any_of>
+    </stop_conditions>
+
+    <main_metric>
+        <avg_rows_per_second/>
+    </main_metric>
+
+    <substitutions>
+       <substitution>
+           <name>expr</name>
+           <values>
+               <value>toString(1 / rand())</value>
+               <value>toString(rand() / 0xFFFFFFFF)</value>
+               <value>toString(0xFFFFFFFF / rand())</value>
+               <value>toString(number)</value>
+               <value>toString(number % 10)</value>
+               <value>toString(rand())</value>
+               <value>toString(rand64())</value>
+               <value>concat(toString(rand(1)), '.', toString(rand(2)))</value>
+               <value>concat(toString(rand(1)), 'e', toString(rand(2) % 100))</value>
+               <value>concat(toString(rand64(1)), toString(rand64(2)), toString(rand64(3)))</value>
+           </values>
+       </substitution>
+    </substitutions>
+
+    <query>SELECT count() FROM system.numbers WHERE NOT ignore(toFloat64({expr}))</query>
+</test>