For users who do not use these functions, it is preferable to turn off them using compiler options. Programmers can get better performance by using these compilers options. When exceptions are disabled, the specifications of the standard libraries will be different. Some compilers support options for subsetting. Sometimes, memory access time depends on the address of the memory.
Some compilers have propriety function for specifying address of data.
Although memory alignment is also important for memory access time, it may waste memory. Or, programmer must specify the best address manually. If a global object is initialized to zero by a constructor, the constructor call may be purely overhead. Because global objects are supposed to be initialized to zero by default. A directive like 'final' in Java which specifies such information can encourage compilers to generate better code.