Explain loop-invariant code motion, Computer Engineering

Assignment Help:

Explain briefly Loop-invariant code motion of the commonly used code optimization techniques.

Loop-invariant code motion

If a quantity is calculated inside a loop during iteration and its value is similar for iteration, this can vastly improve efficiency to hoist this outside the loop and calculate its value just once before the loop begins. It is particularly significant with the address-calculation expressions generated through loops over arrays. For accurate implementation, such technique must be utilized with loop inversion, since not all code is safe to be hoisted outside the loop.

For illustration:

 for (i=1; i≤10, i++){

x=y*2-(1)

.

.

.

}

statement 1 can be hoisted outside the loop assuming value of x and y does not modify in the loop.


Related Discussions:- Explain loop-invariant code motion

What is paging unit, Paging Unit Paging mechanism functions with 4K -...

Paging Unit Paging mechanism functions with 4K - byte memory pages or with a new extension available to Pentium with 4M byte-memory pages. In the Pentium, with the new 4M-byt

What is the function of cu, What is the function of CU? The control uni...

What is the function of CU? The control unit works as the nerve center that coordinates all the computer operations. It issues timing signals that governs the data transfer.

Determine sky wave communication is prone to fading or not, Sky wave Commun...

Sky wave Communication is prone to fading, it is true or false. Ans: It is true that sky wave Communication is prone to fading.

What is branch folding, What is branch folding? The instruction fetch u...

What is branch folding? The instruction fetch unit has implemented the branch instruction concurrently with the implementation of other instructions. This technique is referred

Applications of generic framework for electronic commerce, How are the appl...

How are the applications of generic framework for electronic commerce performed? To perform applications, this is essential to have Supporting Information and Organizational In

What is the use of isolated i/o configuration, What is the use of isolated ...

What is the use of isolated I/O configuration.  In isolated I/O configuration the CPU has distinct input and output instructions and each of these instructions is associated wi

Traditional schema model, (a) Why did SAP introduce the extended star schem...

(a) Why did SAP introduce the extended star schema? Explain why it is reported to be better than the traditional schema model? (b) What is the difference between a dimension use

Define the karnaugh maps (k maps), Define The Karnaugh Maps (K Maps) Th...

Define The Karnaugh Maps (K Maps) The Karnaugh map (K map) provides the systematic method for simplifying a Boolean expression or a truth table function when used properly the

Determine what part of global array to work on thread number, Q. Determine ...

Q. Determine what part of global array to work on thread number? #include void subdomain(float x[ ], int istart, int ipoints) { int i; for (i = 0; i x[istart+

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