When should the register modifier be used? Does it really help?

The register modifier hints to the compiler that the variable will be heavily used and should be kept in the CPU’s registers, if possible, so that it can be accessed faster. There are several restrictions on the use of the register modifier.

First, the variable must be of a type that can be held in the CPU’s register. This usually means a single value of a size less than or equal to the size of an integer. Some machines have registers that can hold floating-point numbers as well.

Second, because the variable might not be stored in memory, its