[PATCH 3/5] ranger: constify range_op_table class

[Andrew Pinski]

While making range_op_table a singleton, I noticed that constification
should be done to `operator[]` and that operator_table could be made
as const as it does not get changed after it is initialized.

Bootstrapped and tested on x86_64-linux.

gcc/ChangeLog:

        * range-op.h (range_op_table): Make operator[] const.
        Have singleton return const reference.
        * range-op.cc (range_op_table::singleton): Update return type.
        (operator_table): Make const.

Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
 gcc/range-op.cc | 4 ++--
 gcc/range-op.h  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index 56a014e99bc..9a889ea4bb4 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -75,7 +75,7 @@ operator_min op_min;
 operator_max op_max;
 
 // Instantaite a range operator table.
-range_op_table &operator_table = range_op_table::singleton();
+const range_op_table &operator_table = range_op_table::singleton();
 
 // Instantiate a default range operator for opcodes with no entry.
 range_operator default_operator;
@@ -118,7 +118,7 @@ range_op_table::range_op_table ()
 }
 
 // Returns the singleton instance of the table.
-range_op_table &range_op_table::singleton()
+const range_op_table &range_op_table::singleton()
 {
   static range_op_table single;
   return single;
diff --git a/gcc/range-op.h b/gcc/range-op.h
index e4e11f89624..f7ecc660fb9 100644
--- a/gcc/range-op.h
+++ b/gcc/range-op.h
@@ -391,12 +391,12 @@ extern void wi_set_zero_nonzero_bits (tree type,
 class range_op_table final
 {
 public:
-  inline range_operator *operator[] (unsigned code)
+  inline range_operator *operator[] (unsigned code) const
     {
       gcc_checking_assert (code < RANGE_OP_TABLE_SIZE);
       return m_range_tree[code];
     }
-  static range_op_table &singleton();
+  static const range_op_table &singleton();
 private:
   inline void set (unsigned code, range_operator &op)
     {
-- 
2.43.0