[PATCH] Add constant folding support for next{after,toward}{,f,l} (PR libstdc++/85466)

[Jakub Jelinek]

On Thu, May 03, 2018 at 06:35:50PM +0200, Jakub Jelinek wrote:
> That requires a machine_mode or tree, but I don't have either of those,
> nor the caller (fold_const_call_sss) has those.
> 
> I could change it to:
>   if (flag_signalling_nans
>       && !flag_finite_math_only
>       && format->has_nans
> so that it would better duplicate what HONOR_SNANS actually tests.
> Though, I think it is ok to punt if one of the operands is a signalling nan
> even if flag_signalling_nans.

Though in theory the arg0's mode for which we have format pointer could
not have nans, but arg1's mode (for which we only have the REAL_VALUE_TYPE)
could have nans (or vice versa).

	Jakub