In some places, GCC uses parameters that are settable from the command line instead of arbitrary hard-wired constants. Many of these parameters control the amount of optimization that is done. For example, GCC does not inline functions that contain more than a certain number of instructions. You can control these parameters with the --param command-line option:
--param name=value --param=name=value
The names of specific parameters, and the meaning of the values, are tied to the internals of the compiler, and are subject to change without notice in future releases. Not all parameters are documented.
To get a list of parameters supported by GCC, use the --help=params option.
The value is an integer. In order to get the minimal, maximal and default values of a parameter, use the --help=param -Q options.