New problem

in fact i know that R deals with logical numbers 0 and 1 the same way
like TRUE and FALSE but my problem is in fact with C language.

Could you please use a meaningful subject line.

I have done an interface with C and my first problem was with float
variables, but this warning doesn't appear everytime and really i don't
know the problem with R:

"Warning message: 
DLL attempted to change FPU control word from 8001f to 9001f"

That's not a problem with R, that is R complaining (correctly) about your
compiled code.  See e.g. the CHANGES file.  I am surmising that you are
using Windows (without saying so) and not using the recommended compiler
(without saying so).  If you follow the recommendations you will not see 
this.

The second problem is how to define my matrix in the function call of R
so that C take it as an input, knowing that for C this matrix is dfine
as: "int M[dimrow][dimcol]" and for R is define as.matrix(m),

An R array is not a C matrix: it is a vector with attributes.  There are
examples in the `Writing R Extensions' manual, `S Programming' and in many 
of the 207 packages on CRAN.

it really hurts interfacing with R

There is an easy way, via reading the manuals, and a hard way, via
trial-and-error.  Your choice, but you will not get sympathy for the 
second.

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595