Re: C Cross compiler for Fairchild 9445

[Alan Lehotsky <lehotsky at sunspot dot tiac dot net>]

> 
> 
> I've been tasked with providing a C cross compiler for the Fairchild 9445 (a
...
> ..otherwise, would
> you please tell me how much work (developer hours) is typically involved in
> developing a GNU cross compiler,
....

	I did a compiler for a 32 bit ASIC using egcs 1.2 as the code
	base last year.  It took me about 5 months working a little
	less than half-time, including doing an assembler and linker
	(using gcc binutils).  I have fairly strong familiarity with
	the GCC internals, I would suggest doubling that time if you
	are not already knowledgeable.

	At least one month of the five (say two man-weeks) was spent
	in tweaking the code for optimization.  [Since it took 3
	instructions worst-case to load an arbitrary 32-bit constant, 
	I put in a lot of effort to optimizing special cases for 1
	and two instruction sequences]

	If your processor has particularly strange runtime behavior or
	limited general-purpose registers, you may need even more
	time.

	I modified ONE file outside the machine-dependent directory
	and the config scripts - and that was to work around a bug.
	In general if you find yourself needing to modify
	machine-independent files, you've probably done something
	wrong and should go back and look at an existing port with
	similar architectural features.
	
	Good luck,
	-- Al Lehotsky