"FOR" in preprocessor macro

[songie D]

would it be possible to sort of engineer some sort of preprocessor macro
that does a 'for' loop.
i.e. for where you would normally use a normal for loop, but when it is
known ay compile time whay the variable is, hence unrolling the loop.

[Carl Daniel [VC++ MVP]]

songie D wrote:

would it be possible to sort of engineer some sort of preprocessor
macro that does a 'for' loop.
i.e. for where you would normally use a normal for loop, but when it
is known ay compile time whay the variable is, hence unrolling the
loop.

http://www.boost.org/libs/preprocessor/doc/index.html

-cd

[Sven Groot]

Carl Daniel [VC++ MVP] wrote:

songie D wrote:

would it be possible to sort of engineer some sort of preprocessor
macro that does a 'for' loop.
i.e. for where you would normally use a normal for loop, but when it
is known ay compile time whay the variable is, hence unrolling the
loop.

http://www.boost.org/libs/preprocessor/doc/index.html

Doesn't VC already do this with a normal for-loop when optimising for speed,
the number of iterations can be determined at compile time, and the amount
of inserted code is reasonable small?

I'm certain I've come across a compiler that did that, but I can't remember
for certain if VC does it though...

--
Sven Groot

http://unforgiven.bloghorn.com

[Carl Daniel [VC++ MVP]]

Sven Groot wrote:

Carl Daniel [VC++ MVP] wrote:

songie D wrote:

would it be possible to sort of engineer some sort of preprocessor
macro that does a 'for' loop.
i.e. for where you would normally use a normal for loop, but when it
is known ay compile time whay the variable is, hence unrolling the
loop.

http://www.boost.org/libs/preprocessor/doc/index.html

Doesn't VC already do this with a normal for-loop when optimising for
speed, the number of iterations can be determined at compile time,
and the amount of inserted code is reasonable small?

I'm certain I've come across a compiler that did that, but I can't
remember for certain if VC does it though...

I'm not sure if VC does automatic loop unrolling, but there definitely are
compilers that do so.

-cd