On Tue, 16 Jun 2015, Maciej W. Rozycki wrote: > This makes me wonder however what the point has been to specify a strict > particular semantics for the copy, negate, abs, copySign operations with > respect to the sign bit of qNaN data where any other operation can then > change the bit in a random fashion. Do you happen to know what the > rationale and any possible use cases considered have been?
I don't know. > Furthermore these checks were deliberately introduced by Richard with his > proposal here <http://gcc.gnu.org/ml/gcc-patches/2006-09/msg00682.html> > and agreed upon in the discussion even before IEEE Std 754-2008 has been > made. Are you suggesting that the arguments used there, that have led to > the current arrangement, no longer stand and consequently the HONOR_NANS > checks introduced are now best dropped? Only the checks for abs and neg patterns are necessary, not those for fused operations. -- Joseph S. Myers jos...@codesourcery.com
