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- Subject: Re: [ANN] LuaProfiler 2.0
- From: Chris Marrin <chris@...>
- Date: Wed, 15 Jun 2005 15:07:52 -0700
Glenn Maynard wrote:
On Wed, Jun 15, 2005 at 02:54:23PM -0400, Aaron Brown wrote:
Glenn Maynard wrote:
However, all of this goes away if you avoid floating-point
entirely.
And use 64-bit ints instead? (Or bignums?)
Yep. Integers are much more easily predictable than floating-point: no
control word to enable unexpected exceptions, change the rounding
order or precision, no loss of precision due to unexpectedly large
values, results are predictable to the bit--they're much better suited
to measuring fine timings than floating point.
(Of course, not all systems have 64-bit ints, but not all systems
have doubles, either. Since this is inherently x86-specific, nonportable
code, that's not much of an issue. For portable code, I usually use
one 32-bit int for seconds, and one for micro- or nanoseconds.)
Actually all machines can have all these data types, it's just a simple
matter of software :-)
For me, I really need to use doubles for two reasons. 1) it is the only
practical datatype understood by Lua and 2) it is easier for content
authors (non-programmers) to understand 1.5 seconds than 1500000
microseconds.
--
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"As a general rule,don't solve puzzles that open portals to Hell"'
