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.