Re: compiling large functions

[Tom St Denis <tstdenis at ellipticsemi dot com>]

Martin Wiebusch wrote:
> Hi,
>
> I'm having trouble compiling generated code, which results in very 
> large function bodies. The structure of the function is quite simple; 
> just a long list of variable = expression assignments, where each 
> expression is at most 30 lines or so. The entire sourcefile can be up 
> to 10MB. (Yes, it's a beast of a calculation.) Even without 
> optimization, gcc uses all my 2Gig of memory and eventually quits with 
> a "cc1plus: out of memory" message.
>
> I have had limited success with splitting up the code into several 
> smaller functions. What puzzles me is that, if I put all functions 
> into the same source file, gcc still uses much more memory than when I 
> put them in separate files (and eventually dies for the 10MB source).
>
> Basically, I'm wondering whether there is a way to tell gcc to just 
> compile (and maybe even optimize?) one assignment at a time and not 
> try to keep the entire function in memory (assuming that that's what 
> it does now).

Try -fno-unit-at-a-time ?

Alternatively, just put the different functions in different files (e.g. 
func1.c, func2.c, func3.c, etc), and generate your makefile 
automatically so you don't need to keep track of the names.

Tom