<< Chapter < Page Chapter >> Page >

What a compiler does

The goal of an optimizing compiler is the efficient translation of a higher-level language into the fastest possible machine language that accurately represents the high-level language source. What makes a representation good is: it gives the correct answers, and it executes quickly.

Naturally, it makes no difference how fast a program runs if it doesn’t produce the right answers. However, you can sometimes trade accuracy for speed. But given an expression of a program that executes correctly, an optimizing compiler looks for ways to streamline it. As a first cut, this usually means simplifying the code, throwing out extraneous instructions, and sharing intermediate results between statements. More advanced optimizations seek to restructure the program and may actually make the code grow in size, though the number of instructions executed will (hopefully) shrink.

When it comes to finally generating machine language, the compiler has to know about the registers and rules for issuing instructions. For performance, it needs to understand the costs of those instructions and the latencies of machine resources, such as the pipelines. This is especially true for processors that can execute more than one instruction at a time. It takes a balanced instruction mix — the right proportion of floating-point, fixed point, memory and branch operations, etc. — to keep the machine busy.

Initially compilers were tools that allowed us to write in something more readable than assembly language. Today they border on artificial intelligence as they take our high-level source code and translate it into highly optimized machine language across a wide variety of single- and multiple-processor architectures. In the area of high performance computing, the compiler at times has a greater impact on the performance of our program than either the processor or memory architecture. Throughout the history of high performance computing, if we are not satisfied with the performance of our program written in a high-level language, we will gladly rewrite all or part of the program in assembly language. Thankfully, today’s compilers usually make that step unnecessary.

In this chapter we cover the basic operation of optimizing compilers. In a later chapter we will cover the techniques used to analyze and compile programs for advanced architectures such as parallel or vector processing systems. We start our look at compilers examining how the relationship between programmers and their compilers has changed over time.

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
How can I make nanorobot?
Lily
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
how can I make nanorobot?
Lily
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Berger describes sociologists as concerned with
Mueller Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, High performance computing. OpenStax CNX. Aug 25, 2010 Download for free at http://cnx.org/content/col11136/1.5
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'High performance computing' conversation and receive update notifications?

Ask