The claimed benefits of high-level languages are now widely accepted. In fact, as computers got faster, modern programming languages added more and more abstractions. For example, modern languages—such as Java, C#, Ruby, Python, F#, PHP, and Javascript—provide such features as automatic memory management, object orientation, static typing, dynamic typing, and referential transparency, all of which ease the programming task. They do that often at a performance cost, but companies chose these languages to improve the correctness and functionality of their software, which they valued more than performance mainly because the progress of Moore’s law hid the costs of abstraction. Although higher levels of abstraction often result in performance penalties, the initial transition away from hand-coded assembly language came with performance gains, in that compilers are better at managing the complexity of low-level code generation, such as register allocation and instruction scheduling, better than most programmers.

That pattern of increases in processor performance coupling with increases in the use of programming-language abstractions has played out repeatedly. The above discussion describes the coupling for general-purpose computing devices, and it is at various stages in other hardware devices, such as graphics hardware, cell phones, personal digital assistants, and other embedded devices.

High-level programming languages have made it easier to create capable, large sophisticated sequential programs. During the height of the synergy between software and increasing single-processor speeds in 1997, Nathan Myhrvold, former chief technology officer for Microsoft, postulated four “laws of software”:3

  1. Software is a gas. Software always expands to fit whatever container it is stored in.
  2. Software grows until it becomes limited by Moore’s law. The growth of software is initially rapid, like gas expanding, but is inevitably limited by the rate of increase in hardware speed.
  3. Software growth makes Moore’s law possible. People buy new hardware because the software requires it.
  4. Software is limited only by human ambition and expectation. We will always find new algorithms, new applications, and new users.

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3These laws were described in a 1997 presentation that the Association for Computing Machinery hosted on the next 50 years of computing (Nathan P. Myhrvold, 1997, The next fifty years of software, Presentation, available at http://research.microsoft.com/en-us/um/siliconvalley/events/acm97/nmNoVid.ppt).



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