Solved

Loop unrolling

Posted on 2002-07-01
1
269 Views
Last Modified: 2010-04-15
What are loop overheads? How are they overcome by unrolling?

Please let me know

Thanks,
Arut
0
Comment
Question by:arut
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 86

Accepted Solution

by:
jkr earned 100 total points
ID: 7121621
A 'loop overhead' is e.g.

int i;

for ( i = 0; i < 3; i++) {

 printf ( "i: %d\n", i);
}

Here, checking whether 'i' is smaller than 3 is the overhead.

'Unrolling' would make it

 printf ( "i: %d\n", i);
 printf ( "i: %d\n", ++i);
 printf ( "i: %d\n", ++i);

thus avoiding the overhead. But, you can also see the limitations if the loop bound is not constant.
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This tutorial is posted by Aaron Wojnowski, administrator at SDKExpert.net.  To view more iPhone tutorials, visit www.sdkexpert.net. This is a very simple tutorial on finding the user's current location easily. In this tutorial, you will learn ho…
Summary: This tutorial covers some basics of pointer, pointer arithmetic and function pointer. What is a pointer: A pointer is a variable which holds an address. This address might be address of another variable/address of devices/address of fu…
The goal of this video is to provide viewers with basic examples to understand and use pointers in the C programming language.
The goal of this video is to provide viewers with basic examples to understand how to use strings and some functions related to them in the C programming language.

627 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question