Pertambahan di bahasa rakitan emu8086 software#
Threaded Code: Hardware and Software Realizations
Pertambahan di bahasa rakitan emu8086 code#
We may now describe a “threaded code computer”–a machine in which an “instruction” controls the PC, or position counter.Ģ. Thus it directs the flow of processing from an accumulator or the equivalent. In the case of an interpreter, an “instruction” is in fact merely a datum from the interpreting program. In the case of hard code an instruction directs the flow of processing by its actual execution from the IR, or instruction register, of the machine. It is instructive to look at the relation between the host hardware and the alternatives discussed. Thus interpretive code tends to be shorter but slower than hard code. This can be a time-consuming proposition. Instead the interpreter must itself be a computer program which simulates the action of the interpretive instruction set in terms of the actual instruction set. The penalty is that the instruction set of the interpreter is not in fact implemented in the computer’s hardware. Obviously such freedom allows a much shorter program for that: problem to be written.
In summary, when writing hard code the user needs relatively many instructions, each of which executes relatively rapidly.Īn interpreter, by contrast, is a vehicle by which the user can choose his own instruction set to correspond to his specific problem. On the other hand, the given instruction set is suboptimal for almost any specific problem because the user is forced to accept unneeded generality in some places and to circumvent a lack of desired generality in others. Each such instruction executes rapidly since it is wired into the physical circuitry of the computer. Each instruction of the program is chosen from the set wired into the host computer by its designers.
The most common alternative techniques of programming might be denoted “hard code” and “interpretive code.” Hard code (or machine code) is the most used method of programming. Under suitable circumstances, it is shown to achieve a desirable balance between speed and small size. In this paper we describe a technique called threaded code of implementing programs. It is normally possible to write a faster and larger (or a smaller but slower) version of a given program. One of the most fundamental tradeoffs in software engineering is that of space versus time. Key Words and Phrases: interpreter, machine code, time tradeoff, space tradeoff, compiled code,subroutine calls, threaded code Extensions and optimizations are mentioned. In software it is realized as interpretive code not needing an interpreter. Hardware and software realizations of it are given. The concept of “ threaded code” is presented as an alternative to machine language code. Semoga penulisan ulang ini bisa memberi manfaat. Author’s address: Digital Equipment Corporation, 146 Main Street, Maynard, MA 01754. General permission to republish, but not for profit, all or part of this material is granted provided that ACM’s copyright notice is given and that reference is made to the publication, to its date of issue, and to the fact that reprinting privileges were granted by permission of the Association for Computing Machinery. Mempublikasi ulang diperbolehkan sesuai dengan kopi-kanan berikut ini:Ĭopyright (~) 1973, Association for Computing Machinery, Inc. Tulisan Threaded Code ini dimuat di majalah/buletin Communications of the ACM June 1973 Volume 16 Number 6. Karena saya merasa sedikit kurang nyaman dengan format dokumen tersebut, akhirnya saya tulis/format ulang supaya lebih nyaman dibaca. Bell yang berjudul “ Threaded Code” yang tersedia dalam bentuk file PDF. Tulisan ini hanyalah salinan tulisan James R.
0 kommentar(er)
