On Mon, 17 Mar 2003 10:08:42 -0500 David Z Maze <[EMAIL PROTECTED]> wrote:
> Jerome BENOIT <[EMAIL PROTECTED]> writes: > > > I have a very naive question: > > Can Debian tune the GNU C Compiler ? > > > > [e.g., put `-cpu=pentium' automaticly on Pentium box] > > There's a pentium-builder package that tries to do this, or you can > try to set CFLAGS for the program in question. With a limited number > of exceptions, though, conventional wisdom is that this buys you > little in performance at the cost of portability of binaries to other > x86-based machines. > > -- Cflags are some kind of black magic thing as it appears to me.I got an AMD Durom 900 so you should think I need to use the duron flag - naah it's athlon-tbird.For reasons like that I don't think you can just have default flags that are guaranteed to work - exept you use i386. If you set the flag with -mcpu=CPU it still generates code that also runs on i386 boxes.Only if you use -march=CPU the code only works on the type of CPU you specify. I usually go with -march=athlon-tbird -O2 -pipe which is pretty conservative and didn't give me any trouble so far. There is really good documentation on the gcc website about all this stuff. Klaus -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
