PATCH: convenience routines for hashtab.c

[Mark Mitchell]

Here are a couple of convenience routines for hashing and comparing
pointers.

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com

2000-04-24  Mark Mitchell  <mark@codesourcery.com>

	* hashtab.h (hash_pointer): Declare.
	(eq_pointer): Likewise.

2000-04-24  Mark Mitchell  <mark@codesourcery.com>

	* hashtab.c (hash_pointer): New function.
	(eq_pointer): Likewise.
	(htab_hash_pointer): New variable.
	(htab_eq_pointer): Likewise.

Index: hashtab.h
===================================================================
RCS file: /cvs/gcc/egcs/include/hashtab.h,v
retrieving revision 1.7
diff -c -p -r1.7 hashtab.h
*** hashtab.h	2000/04/18 20:42:00	1.7
--- hashtab.h	2000/04/24 07:26:17
*************** extern size_t	htab_size	PARAMS ((htab_t)
*** 129,134 ****
--- 129,140 ----
  extern size_t	htab_elements	PARAMS ((htab_t));
  extern double	htab_collisions	PARAMS ((htab_t));
  
+ /* A hash function for pointers.  */
+ extern htab_hash htab_hash_pointer;
+ 
+ /* An equality function for pointers.  */
+ extern htab_eq htab_eq_pointer;
+ 
  #ifdef __cplusplus
  }
  #endif /* __cplusplus */
Index: hashtab.c
===================================================================
RCS file: /cvs/gcc/egcs/libiberty/hashtab.c,v
retrieving revision 1.11
diff -c -p -r1.11 hashtab.c
*** hashtab.c	2000/04/18 20:42:00	1.11
--- hashtab.c	2000/04/24 07:27:42
*************** Boston, MA 02111-1307, USA.  */
*** 56,62 ****
--- 56,70 ----
  #define DELETED_ENTRY  ((void *) 1)
  
  static unsigned long higher_prime_number PARAMS ((unsigned long));
+ static hashval_t hash_pointer PARAMS ((const void *));
+ static int eq_pointer PARAMS ((const void *, const void *));
  
+ /* At some point, we could make these be NULL, and modify the
+    hash-table routines to handle NULL specially; that would avoid
+    function-call overhead for the common case of hashing pointers.  */
+ htab_hash htab_hash_pointer = hash_pointer;
+ htab_eq htab_eq_pointer = eq_pointer;
+ 
  /* The following function returns the nearest prime number which is
     greater than a given source number, N. */
  
*************** higher_prime_number (n)
*** 86,91 ****
--- 94,118 ----
         }
  
    return n;
+ }
+ 
+ /* Returns a hash code for P.  */
+ 
+ hashval_t
+ hash_pointer (p)
+      const void *p;
+ {
+   return (hashval_t) p;
+ }
+ 
+ /* Returns non-zero if P1 and P2 are equal.  */
+ 
+ int
+ eq_pointer (p1, p2)
+      const void *p1;
+      const void *p2;
+ {
+   return p1 == p2;
  }
  
  /* This function creates table with length slightly longer than given