On: Bit Patterns of Float

[dbaupp]

I think that’s not the full story. The standard says:

A quiet NaN bit string should be encoded with the first bit (d1) of the trailing significand field T being 1. A signaling NaN bit string should be encoded with the first bit of the trailing significand field being 0

That does use “should” (not “shall”) and is described as a “preferred encoding”, so it’s standards-compliant to do something else, but it’s not recommended.

[pklausler → dbaupp]

Sure, that's in the 2008 update. But OP was lamenting that the original IEEE-754 didn't encode qNaN/sNaN with the sign bit, no?

[dbaupp → pklausler]

Yeah, you’re right that was the 2008 version. Fair enough.