I want a compiler, or an addon for a compiler, or whatever, that will let me find the number of clock cycles used by my computer to execute a block of code. Example - in C++ I might want to see just how many clock cycles are taken to multiply two given numbers numbers
x = x* y
On installation of it, it could generate a list of assembly commands, look at the block of code in assembly, and count them from there. The compiler basically converts it to assembly anyway (not really, but close enough to maybe work) or it could simply use the program counter and adjust for any jumps that execute.
I've never seen anything like this, but it would be useful as hell for something like deciding which algorithm is best to do something, or rating how fast a system should be to run it, etc