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From Nathan Kurz <>
Subject Re: cast from pointer to integer of different size
Date Fri, 27 Nov 2009 18:21:06 GMT
On Fri, Nov 27, 2009 at 9:47 AM, Marvin Humphrey <> wrote:
> Hash_Code() gets called a lot, and making it 64-bit might have a slight
> negative performance impact for some 32-bit processors.  However, I think
> we should be emphasizing compatibility rather than optimization for 32-bit
> machines and operating systems, freeing us up to optimize for performance on
> 64-bit systems exclusively and reducing the number of variables we have to
> bear in mind.

Yes.  More generally, it might be nice to make such goals explicit somewhere.

Optimized for: 64-bit systems using GCC and supporting mmap would
probably be my vote.
                        Making MSVC a first class citizen would be
fine if you think the return is there.

Supported on: Any modern system with a C99 compiler?  Is there any
real reason to maintain C89 compatibility?

Consciously unsupported: Vax, etc.   Requiring C99 might create a
natural boundary between legacy and 'modern'.

My emphasis is not the specific details, but the idea that one should
draw the lines explicitly so as to focus one's efforts.

Nathan Kurz

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