Is it better to use a macro or a function?

[madhawi]

Is it better to use a macro or a function?

[Ben Pfaff]

madhawi <ma*******@gmai l.comwrites:

Is it better to use a macro or a function?

Some tasks can only be accomplished with a macro. Otherwise, use
a function: in general, they're safer.
--
Ben Pfaff
http://benpfaff.org

[Tor Rustad]

madhawi wrote:

Is it better to use a macro or a function?

There are a number of things that can go wrong with function-like macros,
see C FAQ Question 10.1

so use a function, whenever you can.

--
Tor <torust [at] online [dot] no>

[Tejas Kokje]

madhawi wrote:

Is it better to use a macro or a function?

If functions are relatively short, using a macro is better since it
avoids overhead of stack frame allocation ( saving stack pointer of
caller,saving return address of the instruction in caller function on
the stack frame etc).

However if the functions are long, using macros can be debugging nightmare.

Tejas Kokje

[Kenneth Brody]

madhawi wrote:

>
Is it better to use a macro or a function?

Yes.

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[Chris Dollin]

Tejas Kokje wrote:

madhawi wrote:

>Is it better to use a macro or a function?

If functions are relatively short, using a macro is better since it
avoids overhead of stack frame allocation ( saving stack pointer of
caller,saving return address of the instruction in caller function on
the stack frame etc).

If the functions are relatively short, calling them may well not
involve any stack frame allocation /at all/. The overhead may be
roughly two instructions -- call & return. Or, of course, the compiler
may inline the function completely.

Conclusion: if you want function-like semantics, use functions.

If you want to optimise for speed, for heaven's sake /measure
first/. (Actually, if you want to optimise for anything, measure
first.)

--
Measured But Unoptimised Hedgehog
"Based on their behaviour so far -- I have no idea" /Sahara/

[Eric Sosman]

madhawi wrote:

Is it better to use a macro or a function?

Is it better to use a spoon or a saw?

--
Eric Sosman
es*****@acm-dot-org.invalid

[Richard Tobin]

In article <11************ *********@i13g2 000prf.googlegr oups.com>,
madhawi <ma*******@gmai l.comwrote:

>Is it better to use a macro or a function?

As others have said, functions are cleaner where they work. Now that
support for inline functions is widespread, another large category of
cases can be done with functions.

-- Richard

--
"Considerat ion shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.

[Richard Tobin]

In article <ke************ *************** ***@comcast.com >,
Eric Sosman <es*****@acm-dot-org.invalidwrot e:

>Is it better to use a macro or a function?

Is it better to use a spoon or a saw?

Where both are equally effective, obviously it is better to use a spoon.

-- Richard
--
"Considerat ion shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.

[Flash Gordon]

Tejas Kokje wrote, On 06/06/07 20:28:

madhawi wrote:

>Is it better to use a macro or a function?

If functions are relatively short, using a macro is better since it
avoids overhead of stack frame allocation ( saving stack pointer of
caller,saving return address of the instruction in caller function on
the stack frame etc).

Apart from when it does not. I'm sure it's over 10 years since I read a
compiler manual which talked about it inlining small functions.

1st rule of optimisation, don't do it. Whilst you think using a macro is
for a small function is better due to efficiency you are not ready for
the 2nd rule.

However if the functions are long, using macros can be debugging nightmare.

The same applies to small functions.
--
Flash Gordon