On 11/17/22 17:40, Aldy Hernandez wrote:
To go along with whatever magic we're gonna tack along to the
range-ops sqrt implementation, here is another revision addressing the
VARYING issue you pointed out.
A few things...
Instead of going through trees, I decided to call do_mpfr_arg1
directly. Let's not go the wide int <-> tree rat hole in this one.
The function do_mpfr_arg1 bails on +INF, so I had to handle it manually.
There's a regression in gfortran.dg/ieee/ieee_6.f90, which I'm not
sure how to handle. We are failing because we are calculating
sqrt(-1) and expecting certain IEEE flags set. These flags aren't
set, presumably because we folded sqrt(-1) into a NAN directly:
// All negatives.
if (real_compare (LT_EXPR, &lh_ub, &dconst0))
{
real_nan (&lb, "", 0, TYPE_MODE (type));
ub = lb;
maybe_nan = true;
return;
}
FWIW, we could return [-0.0, +INF] +-NAN which would keep us from
eliding the sqrt, but it'd be a pity to keep the sqrt unless it's
mandated by some IEEE canon.
Aldy
