Calling C/Asm from Espruino...

Super hacky assembler here: https://gist.github.com/gfwilliams/9958815
Doesn't do half what it's supposed to yet, but hopefully could be expanded and added to the Web IDE. I'm thinking something like detecting + replacing:

var adder = E.asm("long(long)",
"movs    r2, #2    "+
"movs    r3, #0   "+
"adds    r2, r2, r0"+
"adc.w   r3, r3, r1"+
"mov r0, r2        "+
"mov r1, r3        "+
"bx  lr            ");