Factor out the code to find gcc, and add a command-line option to override the default executable name. This should help cross-compilation by allowing a cross-gcc to be specified from the configuration file instead of only through the CC environment variable.

void main()
{
    float m[4][4];

    float* fp = &m[0][0];
    for (int i=0; i<16; i++,fp++)
        assert(*fp !<>= 0);
}