Better, cleaner hash function that computes the same on be and le archs.

Should improve sparc64 and other be archs. ok matthew@ miod@

diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c
index 5790781..5db51d5 100644 (file)
--- a/lib/libc/stdlib/malloc.c
+++ b/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: malloc.c,v 1.155 2014/04/22 14:26:26 tedu Exp $       */
+/*     $OpenBSD: malloc.c,v 1.156 2014/04/23 05:43:25 otto Exp $       */
 /*
  * Copyright (c) 2008, 2010, 2011 Otto Moerbeek <otto@drijf.net>
  * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
@@ -217,16 +217,14 @@ static inline size_t
 hash(void *p)
 {
        size_t sum;
-       union {
-               uintptr_t p;
-               unsigned short a[sizeof(void *) / sizeof(short)];
-       } u;
-       u.p = (uintptr_t)p >> MALLOC_PAGESHIFT;
-       sum = u.a[0];
-       sum = (sum << 7) - sum + u.a[1];
+       uintptr_t u;
+
+       u = (uintptr_t)p >> MALLOC_PAGESHIFT;
+       sum = u;
+       sum = (sum << 7) - sum + (u >> 16);
 #ifdef __LP64__
-       sum = (sum << 7) - sum + u.a[2];
-       sum = (sum << 7) - sum + u.a[3];
+       sum = (sum << 7) - sum + (u >> 32);
+       sum = (sum << 7) - sum + (u >> 48);
 #endif
        return sum;
 }