Re: Puzzled by simple test with Lua 5.3

[Tim Hill <drtimhill@...>]

On Jul 12, 2014, at 5:01 PM, Geoff Smith <spammealot1@live.co.uk> wrote:

Hi
 
Here are the numbers I got
 
Running from Scite -->Lua 5.1   :  Time = 9.639 Secs

Running from Dos Console--> Lua 5.1   :  Time = 10.412 Secs

Running from Dos Console--> Lua 5.3   :  Time = 15.236 Secs

So I am seeing a 50% slow going from 5.1 to 5.3, very surprising ?
 

First, as Dirk notes you should build all three versions using VS2008 to be a fair comparison. Second, you really won’t see much difference on a modern Intel x86 CPU. Floating point add/multiply is very efficient on these platforms, and rivals integer operations (which, in fact, is one of the reasons Lua originally justified having no distinct integer type). Try the same tests on an ARM CPU and you will see much more dramatic differences (in favor of 5.3).

—Tim