C or C++ programming mutual assistance group(s) ?

[James McIntosh]

At 09:45 AM 2004/08/16 -0400,  lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart
Sorensen) wrote:

(snip)

>Of course most C++ compilers I have seen also tend to generate much
>bigger slower code than the equivalant C compiler.

My brother is on the team at IBM Research Laboratories to optimize code
from compilers.

If I understand him correctly, C++ has more generalized cases to consider,
and cannot be optimized well unless more information is retained from
initial to final phases of compilation, so that ambiguities can be resolved.

An approach to optimizing C destroys information after it is no longer
necessary.

Although it is not necessary for optimization of C, it is necessary for
proper optimization of C++. At the phase where the information is needed,
it has already been destroyed. 

It is politically difficult to tell people to retain information their work
has no need for, just because the work at a later phase of compilation
requires it.

When one organization innovates by retaining the information so that it can
be used later in the compilation, then I imagine others will follow, and we
will see an industry-wide improvement in execution speed of C++ programmes.

Jim McIntosh   416-292-8126   <jemcinto-cpI+UMyWUv+w5LPnMra/2Q at public.gmane.org>
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