c - What's the point of LEA EAX, [EAX]?

Question

LEA EAX, [EAX]

I encountered this instruction in a binary compiled with the Microsoft C compiler. It clearly can't change the value of EAX. Then why is it there?

Answer 1

It is a NOP.

The following are typcially used as NOP. They all do the same thing but they result in machine code of different length. Depending on the alignment requirement one of them is chosen:

xchg eax, eax         = 90
mov eax, eax          = 89 C0 
lea eax, [eax + 0x00] = 8D 40 00