------- Comment #4 from sgk at troutmask dot apl dot washington dot edu
2006-07-17 18:11 -------
Subject: Re: EXPONENT() broken for real constants
On Mon, Jul 17, 2006 at 05:54:46PM -0000, tobias dot burnus at physik dot
fu-berlin dot de wrote:
>
> I see the same problem for real(8) and for real(10) as for real = real(4),
> except for
> print *, scale (fraction (a), exponent (a)) / a
> where I get "NaN" with real(10) instead of the correct "1.0", which one gets
> for real and real(8).
>
Can you try this patch? It required MPFR 2.2.0.
Index: gcc4x/gcc/fortran/simplify.c
===================================================================
--- gcc4x/gcc/fortran/simplify.c (revision 115505)
+++ gcc4x/gcc/fortran/simplify.c (working copy)
@@ -1049,12 +1049,10 @@ gfc_simplify_exp (gfc_expr * x)
return range_check (result, "EXP");
}
-/* FIXME: MPFR should be able to do this better */
gfc_expr *
gfc_simplify_exponent (gfc_expr * x)
{
int i;
- mpfr_t tmp;
gfc_expr *result;
if (x->expr_type != EXPR_CONSTANT)
@@ -1071,20 +1069,9 @@ gfc_simplify_exponent (gfc_expr * x)
return result;
}
- mpfr_init (tmp);
-
- mpfr_abs (tmp, x->value.real, GFC_RND_MODE);
- mpfr_log2 (tmp, tmp, GFC_RND_MODE);
-
- gfc_mpfr_to_mpz (result->value.integer, tmp);
-
- /* The model number for tiny(x) is b**(emin - 1) where b is the base and
emin
- is the smallest exponent value. So, we need to add 1 if x is tiny(x).
*/
- i = gfc_validate_kind (x->ts.type, x->ts.kind, false);
- if (mpfr_cmp (x->value.real, gfc_real_kinds[i].tiny) == 0)
- mpz_add_ui (result->value.integer,result->value.integer, 1);
-
- mpfr_clear (tmp);
+ /* Requires MPFR 2.2.0 or newer. */
+ i = (int) mpfr_get_exp (x->value.real);
+ mpz_set_si (result->value.integer, i);
return range_check (result, "EXPONENT");
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28276
