Make hash_64() use a 64-bit multiply when appropriate

[pandora-kernel.git] / include / linux / hash.h

diff --git a/include/linux/hash.h b/include/linux/hash.h
index bd1754c..d0494c3 100644 (file)
--- a/include/linux/hash.h
+++ b/include/linux/hash.h
@@ -37,6 +37,9 @@ static __always_inline u64 hash_64(u64 val, unsigned int bits)
 {
        u64 hash = val;
 
+#if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64
+       hash = hash * GOLDEN_RATIO_PRIME_64;
+#else
        /*  Sigh, gcc can't optimise this alone like it does for 32 bits. */
        u64 n = hash;
        n <<= 18;
@@ -51,6 +54,7 @@ static __always_inline u64 hash_64(u64 val, unsigned int bits)
        hash += n;
        n <<= 2;
        hash += n;
+#endif
 
        /* High bits are more random, so use them. */
        return hash >> (64 - bits);