Inline Function

Ilining a function(C++98) is an efficient way to speed up execution.

Rather than making a function call, the function's code is inserted directly at the point where it’s called.

Why ?

Because function calls take more time, and accessing memory is slower. By inlining we eliminate the overhead of the call itself.

Steps of a Non-Inline Function Call:

Function Call:

• The CPU saves the return address (the location to continue after the function) and places it on the stack.

• The CPU then calls the required function.

Passing Arguments:

• Arguments are either loaded into registers or pushed onto the stack (depending on the compiler's decision).

Jump to Function:

• The CPU jumps to the function's memory address to start executing the function and temporarily pauses the execution of the program.

Execute Function Body:

• The CPU runs the code inside the function, for example, calculating x * x.

Return:

• The CPU retrieves the return address from the stack and jumps back to the next instruction in the main program after the function call.

Retrieve Result:

• The result is placed in a register or on the stack, ready for the next instruction (for example, result = 25)

Summary:

• Keep return address → Load arguments in registers/stack → Jump to function’s address → Execute the function → Return result in register/stack.