From: Jan Hubicka <jh@suse.cz>
To: Jan Hubicka <jh@suse.cz>
Cc: Richard Henderson <rth@redhat.com>, gcc-patches@gcc.gnu.org, aj@suse.de
Subject: Re: Simplify floating point conversions II
Date: Wed, 06 Nov 2002 13:19:00 -0000 [thread overview]
Message-ID: <20021106211937.GC1316@atrey.karlin.mff.cuni.cz> (raw)
In-Reply-To: <20021106211059.GB1316@atrey.karlin.mff.cuni.cz>
> > On Wed, Nov 06, 2002 at 06:54:41PM +0100, Jan Hubicka wrote:
> > > + For fast math it would be safe probably to convert (float)sqrt(x)
> > (double)((float)a + (float)b)
> >
> > where A = B = 2**127. The result should be +Inf, not 2**128.
>
> I am doing that only when the mode of + is wider.
> >
> > Finally, I think it is alarmingly incorrect that
> >
> > (float)((double)a + (double)b))
> >
> > does not result in a quantity of type float, as requested.
>
> Here I do that. When a and b are floats, I will produce
> (a+b)
> is that wrong?
I see, you were shooting for something like
(float)((long double)a + (long double)b)
for a and b being double. That will result in (a+b) not casted to float
that is wrong. I am adding recursive call to convert_to_real when this
ahppends.
Honza
>
> Honza
> >
> >
> > r~
next prev parent reply other threads:[~2002-11-06 21:19 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-11-05 9:14 Simplify floating point conversions Jan Hubicka
2002-11-05 9:38 ` Richard Henderson
2002-11-05 9:42 ` Jan Hubicka
2002-11-06 1:23 ` Simplify floating point conversions II Jan Hubicka
2002-11-06 3:08 ` Michael Matz
2002-11-06 4:36 ` Jan Hubicka
2002-11-06 9:54 ` Jan Hubicka
2002-11-06 10:09 ` Richard Henderson
2002-11-06 13:11 ` Jan Hubicka
2002-11-06 13:19 ` Jan Hubicka [this message]
2002-11-06 13:35 ` Gabriel Dos Reis
2002-11-06 13:36 ` Jan Hubicka
2002-11-06 14:06 ` Gabriel Dos Reis
2002-11-06 14:29 ` Converting floor to rint Jan Hubicka
2002-11-06 14:47 ` Richard Henderson
2002-11-06 14:53 ` Jan Hubicka
2002-11-06 14:55 ` Gabriel Dos Reis
2002-11-07 1:21 ` Jan Hubicka
2002-11-07 1:32 ` Jakub Jelinek
2002-11-07 1:33 ` Gabriel Dos Reis
2002-11-07 1:44 ` Jan Hubicka
2002-11-07 1:52 ` Jakub Jelinek
2002-11-07 1:54 ` Jan Hubicka
2002-11-07 2:04 ` Jan Hubicka
2002-11-07 4:47 ` Gabriel Dos Reis
2002-11-07 4:56 ` Jan Hubicka
2002-11-07 5:14 ` Andreas Schwab
2002-11-07 5:27 ` Gabriel Dos Reis
2002-11-07 5:31 ` Jan Hubicka
2002-11-07 5:35 ` Andreas Schwab
2002-11-07 5:22 ` Gabriel Dos Reis
2002-11-07 5:43 ` Andreas Schwab
2002-11-07 6:23 ` Gabriel Dos Reis
2002-11-07 7:01 ` Jan Hubicka
2002-11-07 7:18 ` Gabriel Dos Reis
2002-11-06 13:48 ` Simplify floating point conversions III Jan Hubicka
2002-11-06 14:55 ` Richard Henderson
2002-11-07 2:54 ` Simplify floating point conversions IV Jan Hubicka
2002-11-18 15:01 ` Richard Henderson
2002-11-05 11:14 ` Simplify floating point conversions Geoff Keating
2002-11-06 1:09 ` Jan Hubicka
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