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Re: denormals/subnormals are heading for extinction
- To: gcc at gcc dot gnu dot org, trt at cs dot duke dot edu
- Subject: Re: denormals/subnormals are heading for extinction
- From: dewar at gnat dot com
- Date: Thu, 16 Aug 2001 15:51:34 -0400 (EDT)
<<What sort of non-theoretical evidence is there?
The cited paper is dated 1984, before most of the
architectures listed above even existed.
>>
That does not make the paper invalid, since the value of denormals
is an architecture independent issue ...
<<What?!! Performance on denormals is abysmal on
typical implementations of the following architectures:
ALPHA, SPARC, PA-RISC, IA32, IA64
IBM's POWER and PPC implementations have good performance on denormals.
(Are there any others?)
>>
That's excessive rhetoric. Indeed abysmal, like very is one of those words
that people use when they do not have relevant quantitative data. I have
not seen any application on the ia32 where the overall performance is
significantly affected by the denormal implementation, and would be
very interested to see counter examples. Again, I am thinking about
the entire overall performance of a complete application (nothing
else is relevant).