der Mouse <mouse%Rodents-Montreal.ORG@localhost> writes:
>> The biggest problem with doing global optimization is structural: in
>> Unix the compiler is expected to behave a certain way with respect to
>> object files, and object files have a fixed format and well known
>> semantics.
>
> Not all that much so. For example, if you were to turn .o files into a
> serialization of gcc's internal "tree" structure (I'm handwaving
> tremendously here, I know), the disruption for almost all uses of .o
> files would probably be no greater than the disruption caused by
> switching from a.out to ELF.
There _is_ prior art -- the Amsterdam Compiler Kit, more commonly known
as `that weird compiler in Minix' commonly used raw assembly as an
object format, at least in libraries, and had compiler options to output
(and input for later use) various stages of intermediate languages from
the optimizer passes.
With a little make(1)-fu, you could use these intermediate forms in
place of object files throughout.
More formally, this approach was also used in ANDF -- and is what's
really happening when executing java code under a JIT compiler.
--
Jim Wise
jwise%draga.com@localhost
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