[Cfp-interest] exceptions and flags

[Jim Thomas]

So 754-2008 does not explicitly recommendation a means to detect underflow exceptions, but its recommendation that languages provide alternate exception handling entails detecting underflow exceptions. Maybe Part 5 could leave detection of tiny exact underflow cases as a recommended option, which would allow the simpler slower implementation using flags.

-Jim

On Jun 3, 2014, at 9:32 PM, David Hough CFP <pcfp at oakapple.net> wrote:

>> Does all HW provide a way for SW to detect an underflow exception?
> 
> The only way I know is to enable the underflow trap.    If the trap works
> as recommended by 754-1985, then that suffices.
> 
> But 754-1985 chapter 8 only recommends traps (to implementations) while
> 754-2008 chapter 8 only recommends alternate exception handling (to languages).
> Alternate exception handling replaces traps as far as programming environments
> go, but the traps are still a very likely implementation mechanism.