Else if vs. function()

question about laying out code

in this example the event variable only equals “b” once every 300 frames.

will example B run any faster than example A?
if the code in example A has lots of complicated code that is mostly not activated because the if condition is not allowing it to, does it still make the code run slower? if so, does replacing this with a function make a difference?

EXAMPLE A
onClipEvent (enterFrame) {
if (event==“a”) {
// 1 line of simple code
} else if (event==“b”) {
// 100 lines of very complicated code
}
}

EXAMPLE B
onClipEvent (load) {
function bigFunction () {
// 100 lines of very complicated code
}
}
onClipEvent (enterFrame) {
if (event==“a”) {
// 1 line of simple code
} else if (event==“b”) {
bigFunction();
}
}