Optimize generic ELF hash function a bit more

diff --git a/ChangeLog b/ChangeLog
index 73e9911..93adebd 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-10  Ulrich Drepper  <drepper@gmail.com>
+
+       * sysdeps/generic/dl-hash.h (_dl_elf_hash): Lift one operation out of
+       the inner loop.
+
 2011-12-06  Andreas Schwab  <schwab@linux-m68k.org>
 
        [BZ #13472]

diff --git a/sysdeps/generic/dl-hash.h b/sysdeps/generic/dl-hash.h
index 28312ca..e0db00e 100644 (file)
--- a/sysdeps/generic/dl-hash.h
+++ b/sysdeps/generic/dl-hash.h
@@ -60,9 +60,12 @@ _dl_elf_hash (const char *name_arg)
                         But the following is equivalent and a lot
                         faster, especially on modern processors.  */
 
-                     hash ^= hi;
                      hash ^= hi >> 24;
                    }
+
+                 /* Second part of the modified formula.  This
+                    operation can be lifted outside the loop.  */
+                 hash &= 0x0fffffff;
                }
            }
        }