Espruino speed improvements - compiled JavaScript?

Another update. It now actually does stuff...

function a(b) { 
  "compiled";
  return b+"World"; 
}
console.log(a("Hello "))

Compiles to:

var ASM_BASE=process.memory().stackEndAddres­s;
var ASM_BASE1=ASM_BASE+1/*thumb*/;
[0xb580,0xb401,0x9800,0xb401,0xa00b,0xbf00,0x4f09,0x697f,0xf000,0xf80e,0xb401,0x222b,0xbc02,0xbc01,0x4f05,0x68bf,0xf000,0xf806,0xb401,0xbc01,0xe7ff,0xbc08,0xbd80,0x4770,0x4738,0xbf00,0x74,0x2000,0x6f57,0x6c72,0x64,0x0].forEach(function(v) { poke16((ASM_BASE+=2)-2,v); });

var a = E.nativeCall(ASM_BASE1, "JsVar (JsVar)")
console.log(a("Hello "))

Which does:

 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v72 Copyright 2014 G.Williams
>echo(0);
Hello World
> 

I doubt I'll get much more time to work on it over christmas, but it's looking very promising indeed. Needs a lot of tidying, and I've got to add calls to jsvUnLock and fake a 'frame pointer', but then I can start looking at things like control flow.