I have a question about the compliance of the binary floating point library (libbfp754). In the documentation, a "Note" exists for all of the Quiet Computational Operations (abs, copy, copysign, negate) that states the following:
"When the input is a signaling NaN, two different outcomes are allowed by the standard. The operation could either signal invalid exception with quieted signaling NaN as output, or deliver signaling NaN as output without signaling any exception."
But I believe this is in contradiction with section 5.5.1 of the IEEE 754-2008 standard (not reprintable here), which explicitly states that these functions will only ever affect the sign bit and will not throw exceptions.
I have only seen the bfp754 library perform correctly (passing through a signaling NaN and not signaling an exception) on the two different systems I have compile and run my code on, but I need to know if the other behavior (returning a quiet NaN and signaling an exception) is actually allowed by the library, potentially making my code non-compliant on certain machines.