documentation of trees vs RTL

[Fergus Henderson <fjh at cs dot mu dot oz dot au>]

I've noticed that RTL has a lot more visibility than GCC's "tree"
data structure.  A lot of people who know about RTL don't seem
to know about trees, which leads them to wierd misconceptions
and probably inaccurate conclusions (e.g. that it is hard for a language
front-end to target GCC because you need to generate RTL and RTL is
platform-specific; or that getting GCC to generate MSIL is hopeless, because
RTL doesn't have enough type information [the possibility of generating RTL
from trees not considered]).

So, I think it would be good to have better documentation of GCC's overall
design in (the implementors' section of) the manual.  Last time I looked,
there was a chapter titled "RTL", but very little mention of the tree
data structure.

Well, probably you knew this already.

-- 
Fergus Henderson <fjh@cs.mu.oz.au>  |  "I have always known that the pursuit
                                    |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.