|register storage class
||Register storage class specifier
storage-class-specifier := register
The register storage class is like
auto: it can be used for local objects and
function parameters, and using it means that the declared object has
automatic lifetime. It also provides a hint to the compiler that the
object will be used frequently, so the compiler can optimize access,
perhaps by storing the object in a machine register.
Many modern compilers routinely ignore register
because the compilers are better than humans at allocating registers.
int foo(register int parm)
register int sqr = parm * parm;
auto, type, Chapter 2