[Bug fortran/42809] Too much noise with -Wconversion

["anlauf at gmx dot de" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from anlauf at gmx dot de  2010-01-21 21:11 -------
Created an attachment (id=19684)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19684&action=view)
Slightly improved version of the previous patch

I have improved the patch so that now the following
assignments do not throw a warning: e.g.
real(4) <- integer(1,2)
real(8) <- integer(1,2,4)
dto. for complex on the l.h.s.
This assumes the standard IEEE representations of
reals which have a sufficiently large number of
mantissa bits to accomodate the converted value from
the integer of smaller kind.

It works for me, up to the cases where the converted
value is known to be an integer exactly representable
as a real with the desired kind, see my comment above.

The patch works apparently correctly with
-fdefault-real-8 and -fdefault-integer-8 (ugh!).

I have regtested the patch and found a probably unrelated
failure:

FAIL: gfortran.dg/vect/fast-math-mgrid-resid.f scan-tree-dump-times optimized
"vect_var[^\n]*\+ " 13

The patch is just at the limit of 10 lines, so
whoever wants to take it feel free to do so.
I have left only the work to provide a testcase
for the testsuite. ;-)

Enjoy.


-- 

anlauf at gmx dot de changed:

           What    |Removed                     |Added
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  Attachment #19669|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42809