The answer is a qualified "no",
No, because it is impossible to write a program that will always answer whether code can be made more concise or not. If such a program could exist, you could use it to create a logical paradox (which is why we know it can't exist).
Programs of this nature don't generally exist, because making source code smaller in a mechanical way makes the code less readable. Most programmers just don't see any benefit in making the C code as small as possible.
Yes, because you can use static analysis to find dead code.
People put enormous amounts of research into making programs smaller and faster automatically, using static analysis, but nearly all of that research gets applied to making better optimizers for compilers. Optimizers can produce almost unreadable output, which is why we don't use them to produce source code but object code only.
Keep your source code clean and readable. The compiler will take care of the rest, 99% of the time.
