http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48979
--- Comment #6 from Steve Kargl <sgk at troutmask dot apl.washington.edu> 2011-05-12 19:18:16 UTC --- On Thu, May 12, 2011 at 07:03:34PM +0000, sgk at troutmask dot apl.washington.edu wrote: > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48979 > > --- Comment #5 from Steve Kargl <sgk at troutmask dot apl.washington.edu> > 2011-05-12 18:47:54 UTC --- > On Thu, May 12, 2011 at 05:59:44PM +0000, burnus at gcc dot gnu.org wrote: > > > Whether this really is a bug or not depends on whether one thinks that a > > > standard-compliant Fortran program should compile without requiring > > > special > > > options (I do). > > > > So do I - but the question is whether it is standard conforming. NAN and INF > > are not Fortran numbers, cf. "13.4 Numeric models". Admittedly, IEEE and > > Fortran model numbers are widely mixed in the standard. However, strictly > > speaking, the IEEE functionality is only available if the relevant IEEE > > module > > is loaded and the feature is marked as supported. > > > > >From F2003: > > Page 300: > > A program is prohibited from invoking an intrinsic procedure > under circumstances where a value to be returned in a subroutine > argument or function result is outside the range of values > representable by objects of the specified type and type parameters, > unless the intrinsic module IEEE_ARITHMETIC (section 14) is accessible > and there is support for an infinite or a NaN result, as appropriate. > > Page 364: > > The intrinsic modules IEEE_EXCEPTIONS, IEEE_ARITHMETIC, and > IEEE_FEATURES provide support for exceptions and IEEE arithmetic. > Whether the modules are provided is processor dependent. > > 1) Thomas's program does not USE IEEE_ARITHMETIC. > 2) gfortran does not supply the ieee modules. > > So, calling fraction() with +-Inf and NaN is, I believe, > technically non-conforming. > > I agree that having consistency between constant-folding > and runtime results is desirable, I disagree on calling the > need for -fno-range-check a bug. > Index: simplify.c =================================================================== --- simplify.c (revision 173705) +++ simplify.c (working copy) @@ -2328,6 +2328,12 @@ gfc_simplify_fraction (gfc_expr *x) result = gfc_get_constant_expr (BT_REAL, x->ts.kind, &x->where); + if (mpfr_nan_p (x->value.real) != 0 || mpfr_inf_p (x->value.real) != 0) + { + mpfr_set (result->value.real, x->value.real, GFC_RND_MODE); + return result; + } + if (mpfr_sgn (x->value.real) == 0) { mpfr_set_ui (result->value.real, 0, GFC_RND_MODE); gives 0.00000 0 0.00000 0 0 0.00000 0 0.00000 0 0 NaN 7FD00000 NaN 7FD00000 0 NaN 7FD00000 NaN 7FC00000 0 -Infinity FF800000 -Infinity FF800000 0 -Infinity FF800000 -Infinity FF800000 3 Infinity 7F800000 Infinity 7F800000 0 Infinity 7F800000 Infinity 7F800000 3 fixing exponent is much more involved.
