Explain the data dependency, Computer Engineering

Assignment Help:

Data Dependency

It indicates to the situation in which two or more instructions share same data. The instructions in a program are able to be arranged based on relationship of data dependency. It means how two segments or instructions are data dependent on each other. The subsequent types of data dependencies are identified:

i)  Output dependence: When output of the two instructions I1 and I2 overlap on same data, the instructions are said output dependent.  

ii) I/O dependence: When read and write operations by two instructions are invoked on the same file, it's the condition of I/O dependence.

iii) Flow dependence: If instruction I2 follows I1 and output of I1 becomes input of I2, then I2 is said to be flow dependent on I1

iv) Anti dependence: When instruction I2 follows instruction I1 such that output of instruction I2 overlaps with the input of instruction I1 on the same data.

Think about the subsequent program instructions:

I1: a = b

I2: c = a + d

I3: a = c

In this program segment instructions I1 and I2 are Flow dependent since variable a is produced by instruction I1 as output and used by instruction I2 as input. Instructions I2 and I3 are Anti dependent since variable a is produced by I3 but used by I2 and in sequence I2 comes first. I3 is flow dependent on I2 due to variable c. Instructions I3 and Instruction I1 are Output dependent since variable a is produced by both instructions.


Related Discussions:- Explain the data dependency

What is class and class diagram, What is class, class diagram? An objec...

What is class, class diagram? An object is an instance of a class. Class explains a group of objects with similar properties (attributes), behaviour (operations), kinds of rela

Importance of decentralization, What are the importance of Decentralization...

What are the importance of Decentralization? a) Self responsibility b) Work autonomy c) Quick decisions d) Continuous involvement and e) Better control. What are the differe

What are set up time and hold time constraints, What are set up time and ho...

What are set up time and hold time constraints? What do they mean? Which one is crucial for establishing maximum clock frequency of a circuit? Set up time is the amount of time

Define the difference between static ram and dynamic ram, Define the differ...

Define the difference between static RAM and dynamic RAM? The RAM family comprises two important memory devices that are static RAM (SRAM) and dynamic RAM (DRAM). The main diff

Write examples of declarations of external variables, Examples of declarati...

Examples of declarations of external variables  that  are  not definitions: extern char stack[10]; extern int stkptr; These declarations tell the compiler that the variab

How do you create a permanent cookie, How do you create a permanent cookie?...

How do you create a permanent cookie?  By setting the expiry date of the cookie to a later on time (like 10 years later.)

How to add noise to an image in matlab, The function noise.m, now installed...

The function noise.m, now installed on ashland too, adds Gaussian, salt, uniform and pepper, additive or multiplicative noise to an image

Explain about bus of register transfer, Explain about Bus of register trans...

Explain about Bus of register transfer Since a computer has   several registers, paths must be provided to transfer information among registors. If separate lines are used amon

Cohesion, Identify the type of cohesion in the following statements: 1. ...

Identify the type of cohesion in the following statements: 1. Compute average daily temperatures at various sites 2. Initialize sums and open files 3. Create new temperature rec

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd