[Bug tree-optimization/105740] missed optimization switch transformation for conditions with duplicate conditions

[luoxhu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105740

--- Comment #2 from luoxhu at gcc dot gnu.org ---
Run if_to_switch and convert_switch again after copyprop2 could remove the
redundant statement and expose opportunity for if-to-switch again, is this
reasonable or just move if-to-switch/switch-conversion later run only once?  


diff --git a/gcc/gimple-if-to-switch.cc b/gcc/gimple-if-to-switch.cc
index f7b0b02628b..8f55d0e2f75 100644
--- a/gcc/gimple-if-to-switch.cc
+++ b/gcc/gimple-if-to-switch.cc
@@ -484,6 +484,8 @@ public:
            || bit_test_cluster::is_enabled ());
   }

+  opt_pass *clone () { return new pass_if_to_switch (m_ctxt); }
+
   virtual unsigned int execute (function *);

 }; // class pass_if_to_switch
diff --git a/gcc/passes.def b/gcc/passes.def
index 375d3d62d51..b257307e085 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -243,6 +243,8 @@ along with GCC; see the file COPYING3.  If not see
         Clean them up.  Failure to do so well can lead to false
         positives from warnings for erroneous code.  */
       NEXT_PASS (pass_copy_prop);
+      NEXT_PASS (pass_if_to_switch);
+      NEXT_PASS (pass_convert_switch);
       /* Identify paths that should never be executed in a conforming
         program and isolate those paths.  */
       NEXT_PASS (pass_isolate_erroneous_paths);
diff --git a/gcc/tree-switch-conversion.cc b/gcc/tree-switch-conversion.cc
index 50a17927f39..d5c8262785e 100644
--- a/gcc/tree-switch-conversion.cc
+++ b/gcc/tree-switch-conversion.cc
@@ -2429,6 +2429,9 @@ public:

   /* opt_pass methods: */
   virtual bool gate (function *) { return flag_tree_switch_conversion != 0; }
+
+  opt_pass *clone () { return new pass_convert_switch (m_ctxt); }
+
   virtual unsigned int execute (function *);