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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

what is monopoli power
Adzaho Reply
the situation that prevails when economic forces balance so that economic variables neither increase nor decrease
Bombey
what is equilibrium
Kabir
what are the important of economic to accounting students with references
salihu Reply
Economics is important because it helps people understand how a variety of factors work with and against each other to control how resources such as labor and capital get used, and how inflation, supply, demand, interest rates and other factors determine how much you pay for goods and services.
Muhammad
explain the steps taken by the government in developing rural market?
Azeem Reply
contribution of Adam smith in economics
abel Reply
I will join
Dexter
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Patrick
Hey
Fatima
Hey
Amir
Hello
AS
hey
Umarou
I love this book and i need extra Economic book
Amir
Hey
Amir
what's happening here
AS
I love this book and i need extra Economic book
Amir
what is the meaning of function in economics
Effah Reply
Pls, I need more explanation on price Elasticity of Supply
Isaac Reply
Is the degree to the degree of responsiveness of a change in quantity supplied of goods to a change in price
Afran
what is production
Humaira
Okay what is land mobile and land unmobile
scor
And what are the resources in land
scor
what is production
Humaira
the proces of using the services of labor and equipmnt together with other in puts to make goods and services availble
Bombey
Okay what is land mobile and land unmobile
scor
Discuss the short-term and long-term balance positions of the firm in the monopoly market?
Rabindranath Reply
hey
Soumya
hi
Mitiku
how are you?
Mitiku
can you tell how can i economics honurs(BSC) in reputed college?
Soumya
through hard study and performing well than expected from you
Mitiku
what should i prepare for it?
Soumya
prepare first, in psychologically as well as potentially to sacrifice what's expected from you, when I say this I mean that you have to be ready, for every thing and to accept failure as a good and you need to change them to potential for achievement of ur goals
Mitiku
parna kya hai behencho?
Soumya
Hallo
Rabindranath
Hello, dear what's up?
Mitiku
cool
Momoh
good morning
Isaac
pls, is anyone here from Ghana?
Isaac
Hw s every one please
Afran
Ys please I'm in Ghana
Afran
Hello
OLANIYI
pls anyone from Nigeria
OLANIYI
am a new candidate here, can someone put me 2ru
OLANIYI
hello
OLANIYI
Pls economic A level exam tomorrow pls help me
akinwale
am from Ghana
Jacob
hi
Charles
Pls economic A level exam tomorrow pls help me
akinwale
Hi
Dev
bol Diya discuss ab krega v
Dev
hello Mr. Rabindranath
Dev
what do you want Dimlare
Dev
yes tell me your desire to have it
Dev
to have what?
OLANIYI
Good luck
JOSEPH
I want to know about economic A level tomorrow pls help
Lerato
okay
Umarou
okay
Umarou
hi
Humaira
hi
Liaqat
what is firms
Anteyi Reply
A firm is a business entity which engages in the production of goods and aimed at making profit.
Avuwada
What is autarky in Economics.
Avuwada
what is choice
Tia Reply
So how is the perfect competition different from others
Rev Reply
what is choice
Tia
please what type of commodity is 1.Beaf 2.Suagr 3.Bread
Alfred Reply
1
Naziru
what is the difference between short run and long run?
Ukpen Reply
It just depends on how far you would like to run!!!🤣🤣🤣
Anna
meaning? You guys need not to be playing here; if you don't know a question, leave it for he that knows.
Ukpen
pls is question from which subject or which course
Ada
Is this not economics?
Ukpen
This place is meant to be for serious educational matters n not playing ground so pls let's make it a serious place.
Docky
Is there an economics expert here?
Docky
Okay and I was being serous
Anna
The short run is a period of time in which the quantity of at least one inputs is fixed...
Anna
that is the answer that I found online and in my text book
Anna
Elacisity
salihu
Meaning of economics
Suraj Reply
It will creates rooms for an effective demands.
Chinedum Reply
different between production and supply
babsnof
Hii
Suraj
hlo
eshita
What is the economic?
Suraj
Economics is a science which study human behavior as a relationship between ends and scarce means which has an alternative use.
Mr
what is supply
babsnof
what is different between demand and supply
Debless Reply
Demand refers to the quantity of products that consumers are willing to purchase at various prices per time while Supply has to do with the quantity of products suppliers are willing to supply at various prices per time. find the difference in between
Saye
what is demand
Humaira
demand is a relationship btn the price of an item and the quantity demanded
Bombey
Difference between extinct and extici spicies
Amanpreet 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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