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 are the various hazards encountered in pipelining, What is pipelining?...

What is pipelining? What are the various hazards encountered in pipelining?  Explain in detail. The major characteristics of a pipeline are: a) Pipelining cannot be exe

Is tcp connection-oriented?, Q. Is tcp Connection-oriented? TCP is conn...

Q. Is tcp Connection-oriented? TCP is connection-oriented. This means a connection is established between source and destination machines before any data is sent it implies tha

Explain that lost acknowledgement in packet retransmission, Explain that th...

Explain that the lost acknowledgement does not necessarily enforce retransmission of the packet . To guarantee reliable transfer, protocols utilize positive acknowledgement al

What are the various layers of a file system, What are the various layers o...

What are the various layers of a file system? The file system is composed of lots of dissimilar levels. Each level in the design uses the characteristic of the lower levels to

Illustrate what is a centrifugal force, Q. Illustrate what is a Centrifugal...

Q. Illustrate what is a Centrifugal Force? Answer:- Centrifugal force is the force that is equivalent in magnitude but opposite in direction to the centripetal force which

Stata about the magnetic stripes, Stata about the Magnetic stripes  Th...

Stata about the Magnetic stripes  These comprise information/data stored on magnetic material often on the back of a credit/debit card; the information is automatically read b

What are the requirements a dialog program must fulfill, What are the requi...

What are the requirements a dialog program must fulfill? A dialog program must fulfil the following requirements A user friendly user interface. - Format and consistency

Illustrate cache dram, Q. Illustrate Cache DRAM? Cache DRAM (CDRAM) wh...

Q. Illustrate Cache DRAM? Cache DRAM (CDRAM) which is developed by Mitsubishi integrates a tiny SRAM cache (16Kb) on a generic DRAM chip. SRAM on the CDRAM can be used in two

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