On Tuesday, 26 August 2014 at 12:37:58 UTC, Ola Fosheim Grøstad
wrote:
On Tuesday, 26 August 2014 at 10:55:20 UTC, Don wrote:
It was always in IEEE754. The decision in 754-2008 was simply
to not remove it from the spec (a lot of people wanted to
remove it). I don't think anything has changed.
It was implementation defined before. I think they specified
the bit in 2008.
fld uninitialized_var;
fstp other_var;
This is not SSE, but I guess MOVSS does not create exceptions
either.
No, it's more subtle. On the original x87, signalling NaNs are
triggered for 64 bits loads, but not for 80 bit loads. You have
to read the fine print to discover this. I don't think the
behaviour was intentional.