Selecting i686 for compiled code?

["Randolph S. Kahle" <RandyKahle@KahleAssociates.com>]

I am compiling my first set of code under Debian and the
Debian package management system.

I downloaded the source for bash and I want to try to
compile it for the i686 instruction set and with O3
optimization level.

I am using the

debian/rules build

method and I am not able to figure out how to
set up the environment for something other
than i386 instruction set.

I looked at dpkg-architecture, but that selects
the processor family (i386, m68k, etc.), but
not the specific processor type.

Can someone point me in the right direction?

Thanks!

Randy