Re: IPA

[Daniel Berlin <dberlin@dberlin.org>]

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On Thu, 14 Oct 2004, Kenneth Zadeck wrote:

> If you look at most other optimizing compilers (i.e. sun, ibm, llvm),
> they have enhanced .o formats that contain the intermediate code that can
> then be further optimized.  This solves a huge number of legistical
> problems, such as getting the user to change their entire build
> procedures and makefiles.  All you have to do is add a few options onto
> the link command.  It also means that if a single file changes, all you
> do is recompile the one file and do a (notably more expensive) link. 
> 
> The other benefit is that since a fair amount of the analysis is done
> locally before you do the intermodular stuff, it is generally faster to
> rebuild after small changes to a single file.
> 
> However, this violates one of the stallman principals of not wanting to
> have a defined api for the intermediate form of the compiler.  So we are
> forced to do something that is inferior and that, most likely, will not
> be widely used.

Except that when it becomse necsesary to do this, we'll simply do it, and 
stallman has said that would be okay.
Or so i'm told.
He just doesn't want us doing it unless it absoultely necessary to keep 
gcc competitive.