Date: Sun, 6 Apr 1997 12:04:01 +0200 (MET DST) From: hm@kts.org (Hellmuth Michaelis) To: freebsd-hackers@freebsd.org Subject: How to declare device driver variables and data structures ? Message-ID: <m0wDonp-00002GC@ernie.kts.org>
next in thread | raw e-mail | index | archive | help
Inside a device driver or a piece of kernel software, how should one decleare the size of variables (if one has the choice): i.e. if i know a variable can only have values 0 ... 32, shall i make it an unsigned char ? Is it slower to make such variables an unsigned int or an unsigned short ? What are the space vs. speed considerations ? i.e. if i know a variable can only have values 0 ... 2048, shall i make it an unsigned short ? Is it slower to make such variables an unsigned int ? another i.e. for boolean variables, is it better to make them chars, shorts or ints ? signed or unsigned ? What is the speed of unsigned variables vs. signed variables ? What is with future ports to other architectures ? How does this all apply to variables being part of structures ? hellmuth -- hellmuth michaelis hm@kts.org hamburg, europe
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?m0wDonp-00002GC>