hashtab.c (hash_pointer): Remove conditional and avoid unexecuted shift equal to wordsize.

2013-05-06  David Edelsohn  <dje.gcc@gmail.com>
            Peter Bergner  <bergner@vnet.ibm.com>
            Segher Boessenkool  <segher@kernel.crashing.org>
            Jakub Jelinek  <jakub@redhat.com>

        * hashtab.c (hash_pointer): Remove conditional and avoid
        unexecuted shift equal to wordsize.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>
Co-Authored-By: Peter Bergner <bergner@vnet.ibm.com>
Co-Authored-By: Segher Boessenkool <segher@kernel.crashing.org>

From-SVN: r198633

libiberty/ChangeLog

+2013-05-06  David Edelsohn  <dje.gcc@gmail.com>
+	    Peter Bergner  <bergner@vnet.ibm.com>
+	    Segher Boessenkool  <segher@kernel.crashing.org>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	* hashtab.c (hash_pointer): Remove conditional and avoid
+	unexecuted shift equal to wordsize.
+
 2013-04-22  Andi Kleen <ak@linux.intel.com>
 
 	* hashtab.c (hash_pointer): Move to end of file and reimplement.

libiberty/hashtab.c

@@ -990,17 +990,8 @@ hash_pointer (const PTR p)
   unsigned a, b, c;
 
   a = b = 0x9e3779b9;
-  if (sizeof (intptr_t) == 4) 
-    {
-      /* Mix as 16bit for now */
-      a += v >> 16;
-      b += v & 0xffff;
-    }
-  else
-    {
-      a += v >> 32;
-      b += v & 0xffffffff;
-    }
+  a += v >> (sizeof (intptr_t) * CHAR_BIT / 2);
+  b += v & (((intptr_t) 1 << (sizeof (intptr_t) * CHAR_BIT / 2)) - 1);
   c = 0x42135234;
   mix (a, b, c);
   return c;