constify inchash

The following constifies parts of inchash.

	* inchash.h (inchash::end): Make const.
	(inchash::merge): Take const reference hash argument.
	(inchash::add_commutative): Likewise.

diff --git a/gcc/inchash.h b/gcc/inchash.h
index e88f9b5eac189526c103573b7119ac4aedcd045b..82f50eb0f258e0e5269d802dec060fb9659669b9 100644 (file)
--- a/gcc/inchash.h
+++ b/gcc/inchash.h
@@ -46,7 +46,7 @@ class hash
   }
 
   /* End incremential hashing and provide the final value.  */
-  hashval_t end ()
+  hashval_t end () const
   {
     return val;
   }
@@ -109,7 +109,7 @@ class hash
   }
 
   /* Hash in state from other inchash OTHER.  */
-  void merge (hash &other)
+  void merge (const hash &other)
   {
     merge_hash (other.val);
   }
@@ -136,7 +136,7 @@ class hash
      based on their value. This is useful for hashing commutative
      expressions, so that A+B and B+A get the same hash.  */
 
-  void add_commutative (hash &a, hash &b)
+  void add_commutative (const hash &a, const hash &b)
   {
     if (a.end() > b.end())
       {