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Unformatted text preview: on the computer in whose assembly language it has been written. Thus, a
decision to change to another computer will require learning a new language and
the conversion of all existing programs into the assembly language of the new
Knowledge of hardware required. Since assembly languages are machine
dependent, an assembly language programmer must have a good knowledge of the
characteristics and the logical structure of his/her computer in order to write good
assembly language programs.
3. Machine level coding. In case of an assembly language, instructions are still
written at the machine-code level. That is, one assembly language instruction is
substituted for one machine language instruction. Thus writing assembly language
programs is still time-consuming and not very easy.
Typical Uses of Assembly Language
Due to the above mentioned limitations of assembly languages, programmers
rarely write programs of any significant size in assembly language today. Today
assembly language programming is done only when a program's execution
efficiency is very important. Assembly language programming helps in producing
compact, fast, and efficient code because it gives the programmer total control of
the computer's CPU, memory and registers. Hence, assembly language
programming is mainly used today to fine-tune important parts of programs
written in a higher-level language. High-level language programs that are
candidates for this type of fine-tuning are those whose execution consumes a
substantial part of the total computing resources at their installations, and hence offer real payoffs for any improvement in execution time. In such circumstances, a
clever programmer who is familiar with the compiler-generated code for the highlevel language program, and also with the purpose of the program at hand, is very
likely to be able to improve it significantly by rewriting in assembly language
some small but critical section of it. It would not be very unusual for the
programmer to be able to improve the program’s performance by an order of
magnitude by rewriting...
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This document was uploaded on 04/07/2014.
- Spring '14