On 8/29/22 16:36, Aldy Hernandez wrote:
On Mon, Aug 29, 2022 at 4:30 PM Toon Moene <t...@moene.org> wrote:
On 8/29/22 16:15, Aldy Hernandez wrote:
But even with -ffinite-math-only, is there any benefit to propagating
a known NAN? For example:
The original intent (in 2002) for the option -ffinite-math-only was for
the optimizers to ignore all the various exceptions to common
optimizations because they might not work correctly when presented with
a NaN or an Inf.
I do not know what the effect for floating point range information would
be - offhand.
But in the *spirit* of this option would be to ignore that the range
[5.0, 5.0] would "also" contain NaN, for instance.
Hmm, this is somewhat similar to what Jakub suggested. Perhaps we
could categorically set !NAN for !HONOR_NANS at frange construction
time?
For reference:
bool
HONOR_NANS (machine_mode m)
{
return MODE_HAS_NANS (m) && !flag_finite_math_only;
}
Thanks.
Aldy
Yep, I think that would do it.
Thanks,
--
Toon Moene - e-mail: t...@moene.org - phone: +31 346 214290
Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
