On Mon, Apr 22, 2013 at 01:46:58PM +0200, Richard Biener wrote: > On Fri, Apr 19, 2013 at 11:31 PM, Andi Kleen <a...@firstfloor.org> wrote: > > From: Andi Kleen <a...@linux.intel.com> > > > > For a large LTO test case The previous pointer hash change brought > > the collision rate for the WPA gimple type hash table from 90% to > > 70. This patch uses the well known murmur3 to improve it further > > to 64%. > > But if they are pointers then pointer_hash should be good enough... ?
The original pointer hash (ptr >> 3) % hashsize and throwing away most bits is very poor. The evahash based on I sent earlier is better, but murmur3 is even better than that, at least for this case. -Andi
