This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [tree-ssa] tree-ssa-dom.c: Fix PR 14303.


Hi Jeff and Roger,

>  >I believe the transformation fabs(x) < 0.0 into false is always safe
>  >even in the presence of NaNs.  The reveresed form, fabs(x) >= 0.0
>  >into true, however is unsafe as fabs(NaN) = NaN, so NaN >= 0.0 would
>  >be false.
> Ah OK.  Based on that, then going with Kazu's patch is reasonable in the
> short term -- until such time as we can/do track FP ranges.

Does this mean the patch is OK to apply?  One thing I am worried about
is that no part of tree-ssa-dom.c has an expression transformation as
bold as my patch.  Should I build a dummy tree node and have fold()
fold it?

Kazu Hirata


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]