I would prefer some doxygen compliant documentation this way:
/**
* Description of the behavior/purpose of your method
*
* @param v The float 'v' (whatever this means)
* @param w Optional float 'w' (whatever this means), default value is 1.0.
*/
void method1(float v, float w =1.0);
Usually I'm not going to put additional comments with implementation specific blocks,