least-positive vs least-positive-normalized

Daniel KochmaƄski daniel at turtleware.eu
Wed Jan 30 07:07:44 UTC 2019


> With ecl 16.1.3, I noticed that least-positive-double-float and
> least-positive-normalized-double-float are exactly equal.  This is
> allowed, but ecl can work with denormals since (/
> least-positive-normalized-double-float 10) is printed correctly.

The reason they are the same is because portable C gives us DBL_MIN at
our disposal (and its counterparts for other floats).
> Maybe these two values should be different?

 Maybe we could hardcode other value when ieee-floating-point is in
featuers (fwiw it is an optional build flag). I'm not sure what would
be the right thing here.
> Or maybe ecl really meant to turn on flush-to-zero so that no
> denormals can
> occur?

ECL signals a floating-point-overflow/underflow conditions unless
disabled by an internal function si:trap-fpe.


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