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in your file, getchar is replaced with a macro definition at compile time, replacing the C library function.

You can make cpp macros work for FORTRAN programs too. Some programmers use the standard UNIX m4 preprocessor for FORTRAN For example, a FORTRAN version of the C program above might look like this:


#define AVERAG(X,Y) ((X+Y)/2) CPROGRAM MAIN REAL A,P,QDATA P,Q /50.,100./ A = AVERAG(P,Q)WRITE (*,*) A END

Without a little preparation, the #define statement is rejected by the FORTRAN compiler. The program first has to be preprocessed through cpp to replace the use of AVERAG with its macro definition. It makes compilation a two-step procedure, but that shouldn’t be too much of a burden, especially if you are building your programs under the control of the make utility. We would also suggest you store FORTRAN programs containing cpp directives under filename.F to distinguish them from unadorned FORTRAN. Just be sure you make your changes only to the .F files and not to the output from cpp . This is how you would preprocess FORTRAN .F files by hand:


% /lib/cpp -P<average.F>average.f % f77 average.f -c

The FORTRAN compiler never sees the original code. Instead, the macro definition is substituted inline as if you had typed it yourself:


C PROGRAM MAINREAL A,P,Q DATA P,Q /50.,100./ A = ((P+Q)/2)WRITE (*,*) A END

By the way, some FORTRAN compilers recognize the .F extension already, making the two-step process unnecessary. If the compiler sees the .F extension it invokes cpp automatically, compiles the output, and throws away the intermediate .f file. Try compiling a .F on your computer to see if it works.

Also, be aware that macro expansions may make source lines extend past column 72, which will probably make your FORTRAN compiler complain (or worse: it might pass unnoticed). Some compilers support input lines longer than 72 characters. On the Sun compilers the –e option allows extended input lines up to 132 characters long.

Procedure inlining

Macro definitions tend to be pretty short, usually just a single statement. Some- times you have slightly longer (but not too long) bits of code that might also benefit from being copied inline, rather than called as a subroutine or function. Again, the reason for doing this is to eliminate procedure call overhead and expose paral- lelism. If your compiler is capable of inlining subroutine and function definitions into the modules that call them, then you have a very natural, very portable way to write modular code without suffering the cost of subroutine calls.

Depending on the vendor, you can ask the compiler for procedure inlining by:

  • Specifying which routines should be inlined on the compiler’s command line
  • Putting inlining directives into the source program
  • Letting the compiler inline automatically

The directives and compile line options are not standard, so you have to check your compiler documentation. Unfortunately, you may learn that there is no such feature (“yet,” always yet), or that it’s an expensive extra. The third form of inlining in the list, automatic, is available from just a few vendors. Automatic inlining depends on a sophisticated compiler that can view the definitions of several modules at once.

There are some words of caution with regard to procedure inlining. You can easily do too much of it. If everything and anything is ingested into the body of its parents, the resulting executable may be so large that it repeatedly spills out of the instruction cache and becomes a net performance loss. Our advice is that you use the caller/callee information profilers give you and make some intelligent decisions about inlining, rather than trying to inline every subroutine available. Again, small routines that are called often are generally the best candidates for inlining.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, High performance computing. OpenStax CNX. Aug 25, 2010 Download for free at http://cnx.org/content/col11136/1.5
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