Re: Link-time optimzation

[Richard Earnshaw <rearnsha@gcc.gnu.org>]

On Thu, 2005-11-17 at 01:27, Mark Mitchell wrote:
> Richard Henderson wrote:
> > In Requirement 4, you say that the function F from input files a.o and
> > b.o should still be named F in the output file.  Why is this requirement
> > more than simply having the debug information reflect that both names
> > were originally F?  I see you go to some length in section 3 to ensure
> > actual symbol table duplicates, and I don't know why.
> 
> Our understanding was that the debugger actually uses the symbol table,
> in addition to the debugging information, in some cases.  (This must be
> true when not running with -g, but I thought it was true in other cases
> as well.)  It might be true for other tools, too.
> 
> It's true that, from a correctness or code-generation point of view, it
> shouldn't matter, so, for non-GNU assemblers, we could fall back to
> F.0/F.1, etc.

We spend a lot of time printing out the results of compilation as
assembly language, only to have to parse it all again in the assembler. 
Given some of the problems this proposal throws up I think we should
seriously look at bypassing as much of this step as possible, and of
generating object files from directly in the compiler.  Ultimately we'd
only need to parse assembly statements for inline asm constructs.

R.