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Date: Sat, 11 Jun 2011 09:13:00 -0000
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Subject: Re: [patch, libgfortran] PR48906 Wrong rounding results with -m32
From: Thomas Henlich <thenlich@users.sourceforge.net>
To: Janne Blomqvist <blomqvist.janne@gmail.com>
Cc: jerry DeLisle <jvdelisle@charter.net>, gfortran <fortran@gcc.gnu.org>, 	gcc patches <gcc-patches@gcc.gnu.org>
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> I don't agree with this; with the patch we now output 10 significant
> digits, whereas 9 is sufficient for a binary->ascii->binary roundtrip.
> So please retain the "reduce d by one when E editing is used" thing
> for list format and G0. This is just a side effect of using 1PGw.d
> format for list format and G0 in order to avoid duplicating code, but
> we don't need to follow this particular craziness that is due to how
> the scale factor is specified in the standard.

I hadn't noticed this, but I agree with Janne.

It should be easy to implement:

After the switch between F and E editing, we just need to shift the
decimal point and decrement the exponent. No new rounding is required,
because we keep the number of significant digits.