On 21 November 2005 14:57, Matt wrote:
I was doing some work with Word64 and noticed that it was about 3 times slower than Int64. The reason appears to be expensive conversions from Int64# to Word64# and vice versa. I modified the libraries to remove the conversion overhead, and the result is that Int64# and Word64# now have equal performance, at least on the domain that I tested (==, +, -).
I can't check into the tree, so I was told to send my changes to this list. Could someone else check them in? I have attached a patch file representing my changes.
Thanks for the patch - but could you try this instead? int64ToWord64# = unsafeCoerce# word64ToInt64# = unsafeCoerce# this should reduce the cost of the conversions to zero, which is a simpler way to fix the performance bug (if it works). If you confirm that this also improves performance, I'll commit it. If not, I'll commit your patch instead. Cheers, Simon