Mostly deobfuscated:

    int putchar ( int ) ;

    int main ( void )
    {
        int z ;
        for (z = 0; z < 90; z++)
        {
            putchar (
                z % 9 + z / 9 > 3 &&
                z % 9 + z / 9 < 14 &&
                z / 9 < z % 9 + 6 &&
                z / 9 > z % 9 - 5 ? '*' : ' ' );

            if (!(z % 9 - 9 + 1))
                putchar ( '\n' );
        };
        putchar ( '\n' ) ;
        return 0;
    }

It's too late at night for me to try to simplify that big expression in the middle...