On Fri, Aug 7, 2026 at 9:31 AM Alexander Monakov <[email protected]> wrote: > > > On Wed, 5 Aug 2026, Roger Sayle wrote: > > > Likewise when x is NaN, 0.0 - x > > may change the payload, but -x is guaranteed not to. > > Not saying you should drop the condition in your patch, but do we care > about NaN payload propagation anywhere else? The HONOR_NANS et al. only > seem to cover presence/absence of NaNs, not observability of payloads.
I think we don't. -x will still turn sNaN into qNaN? > > gcc/ChangeLog > > PR tree-optimization/126467 > > * match.pd (0.0 - x -> -x): Update the conditions under which > > the transformation is performed, disallowing x = +0.0 when we > > honor signed zeros. > > (this doesn't seem to mention NaNs) > > Alexander
