[R] Code density functions

[F Z]

Hello

I would like to see the algorithm that R uses to generate density functions 
for several distributions (i.e. Normal,Weibull, etc).  I tried:

>dnorm
function (x, mean = 0, sd = 1, log = FALSE)
.Internal(dnorm(x, mean, sd, log))
<environment: namespace:stats>

How can I see the code used for densities?

Thanks!