Hi, > This is looking pretty close to ready to go in, but the patch also seems > to be doing several things at once and it might be easier to review if > split into separate logical pieces. For example (this is an illustration, > not necessarily saying it should be exactly this way): (1) Add > REAL_VALUE_ISSIGNALING_NAN and convert existing logic that already does > something equivalent (so no semantic change, just cleanup). (2) Convert > existing code that checks for all NaNs in cases where > REAL_VALUE_ISSIGNALING_NAN would be enough. (3) Treat rint and nearbyint > the same. (4) Make real.c operations properly produce quiet NaNs for > operations with signaling NaN input. (5) Disable various transformations > for signaling NaN operands, where folding them loses exceptions.
Thanks, I will break it up into multiple patches as you proposed. > This patch is also getting big enough that it would be a good idea to > complete the copyright assignment paperwork, certainly if you plan to make > more contributions in future, if you're not covered by a corporate > assignment. I have a corporate assignment, I will post the patches from my corporate email id. >> @@ -1943,7 +1965,17 @@ fold_convert_const_real_from_real (tree type, cons >> REAL_VALUE_TYPE value; >> tree t; >> >> + /* Don't perform the operation if flag_signaling_nans is on >> + and the operand is a NaN. */ >> + if (HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))) >> + && REAL_VALUE_ISSIGNALING_NAN (TREE_REAL_CST (arg1))) >> + return NULL_TREE; >> + >> real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1)); >> + /* Make resulting NaN value to be qNaN when flag_signaling_nans >> + is off. */ >> + if (REAL_VALUE_ISSIGNALING_NAN (value)) >> + value.signalling = 0; > > Shouldn't real_convert do this rather than the caller needing to do it? Yes, it should be. I had started by doing this within real_convert but then saw that there are quite a few callers where I should add the check for flag_signaling_nans. This was making the patch bigger, so instead decided to change the caller in this particular case. I will try to make the change in real_convert now that we are planning to break the patch. Regards, Sujoy > -- > Joseph S. Myers > jos...@codesourcery.com
