Can I build under Linux a gcc-3.1 which would work as mingw32?

["Tom Womack" <tom at womack dot net>]

OK, my final aim here is to have a gcc which is hosted on Windows, produces
Windows executables, and implements gcc -march=pentium4, so I don't have to
switch to Visual C++ whenever I want to write something with an SSE2
intrinsic in.

Do I need anything beyond
* a source release of binutils
* a source snapshot of gcc-3.1

I presume I build binutils -host=linux -target=linux and install it as the
main binutils on the system, then from a second copy of the source I build
binutils -host=linux -target=win32-mingw32 -install-suffix=-win.

Then I compile gcc-3.1 -host=linux -target=linux -install-suffix=-3.1

With the new binutils and gcc-3.1, I can then build
gcc-3.1 -host=linux -target=win32-mingw32 -install-suffix=-targetting-window
s? How do I tell the build process to use the win32-targetted binutils?

And presumably I then use gcc-targetting-windows to build a
host=win32-mingw32 target=win32-mingw32 install-suffix=-win-on-win, then
move a quantity of .EXE files over to my Windows partition?

This must be a routine thing to do; is it automated anywhere, so I type an
obvious command and then leave the P4 compiling overnight?

Tom