On Wed, Jan 4, 2012 at 10:04 AM, William Ahern
<william@25thandclement.com> wrote:
On Tue, Jan 03, 2012 at 10:43:07PM -0800, William Ahern wrote:
<snip>
> h0 = h ^ ((h<<5) + (h>>2) + src[0]);
> h1 = h ^ ((h<<5) + (h>>2) + src[1]);
> h2 = h ^ ((h<<5) + (h>>2) + src[2]);
> h3 = h ^ ((h<<5) + (h>>2) + src[3]);
> h4 = h ^ ((h<<5) + (h>>2) + src[4]);
> h5 = h ^ ((h<<5) + (h>>2) + src[5]);
> h6 = h ^ ((h<<5) + (h>>2) + src[6]);
> h7 = h ^ ((h<<5) + (h>>2) + src[7]);
> h = h0 | h1 | h2 | h3 | h4 | h5 | h6 | h7;
Note that h0, h1, h2 etc all get the same value of the _expression_ '(h << 5) + (h >> 2)', which may not be what you want......
Gé
Oops. Those were intended to be ^s, not |s. It's faster with xor, anyhow.
Well within factor of 2 runtime. Which isn't surprising because even with
the Lua algorithm doing a fixed 32 hash operations, string interning is
still O(N) overall because of memcpy().
