Bug#268757: gcc-3.4-doc: x86_64 -march=*, -m64 option documentation needs clarification

[Karl Hegbloom <hegbloom@pdx.edu>]

On Sat, 2004-11-13 at 08:26 +0100, Matthias Klose wrote:
> > `-m32'
> > `-m64'
> >      Generate code for a 32-bit or 64-bit environment.  The 32-bit
> >      environment sets int, long and pointer to 32 bits and generates
> >      code that runs on any i386 system.  The 64-bit environment sets
> >      int to 32 bits and long and pointer to 64 bits and generates code
> >      for AMD's x86-64 architecture.
> > 
> > It is not clear in the above paragraph whether -m64 implies -march=k8
> > or what.  It probably should not...  I am not an expert, that's why I
> > went to the manual.  Can you please fix it?
> 
> GCC never turns something on, which you don't explicitely specify on
> the command line. Not sure how you want the documentation be changed.
> -m64 turns on the common subset for all  x86-64 architectures,
> specifying -march=k8 turns on k8/opteron specific features,
> -march=nocona turns on some P4/64 Nocona specific features.
> 

Well, there.  That's exactly the kind of clarification needed in the
manual.  Somewhere in there it should say that.

-- 
    Karl Hegbloom
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