View stack pointer in Xcode

I have attempted a partial answer to this question:

CPU cost order of magnitude for some basic operations

just because it was an interesting exercise whilst I am learning to use Xcode.

My answer would hold a little more water if I could identify the stack pointer in Xcode when targetting iOS. I know how to find my way to the registers, but I don't 开发者_JS百科know which one is SP.

Cheers!

Just earned the tumbleweed badge for this!

I have now discovered the answer. It's usually r13 in ARM processors, and is labelled $sp in the Xcode debugger. Obvious really, when you actually look for it!