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From: Ian Lance Taylor <iant@google.com>
To: Gidi Nave <gidi.nave.1@gmail.com>
Cc: gcc@gcc.gnu.org
Subject: Re: Plus Reload
Date: Tue, 11 Jan 2011 17:22:00 -0000	[thread overview]
Message-ID: <mcrmxn74apa.fsf@google.com> (raw)
In-Reply-To: <AANLkTimrGVFRGkQddNj7FmAO9mT8na2VxFFgzGyfyC76@mail.gmail.com>	(Gidi Nave's message of "Tue, 11 Jan 2011 18:03:03 +0200")

Gidi Nave <gidi.nave.1@gmail.com> writes:

> On Tue, Jan 11, 2011 at 5:34 PM, Ian Lance Taylor <iant@google.com> wrote:
>
>> So why doesn't d1 = d1 + -96 match the last instruction there?
>>
> because it's:    add d,d unsigned
> we don't have:  add d,d signed
>
> and in this case we need: d = r + (-96)

(Please don't top-post on this mailing list.  Thanks.)

Addition of signed and unsigned numbers is the same operation at the
machine level.  Are there limitations on the signed value?  If so, is
there is a sub instruction?

Ian

  reply	other threads:[~2011-01-11 17:22 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-11 13:30 Gidi Nave
2011-01-11 14:31 ` Ian Lance Taylor
2011-01-11 14:59   ` Gidi Nave
2011-01-11 15:02     ` Gidi Nave
2011-01-11 15:34     ` Ian Lance Taylor
2011-01-11 16:03       ` Gidi Nave
2011-01-11 17:22         ` Ian Lance Taylor [this message]
2011-01-12  6:04           ` Gidi Nave
2011-01-12  6:28             ` Ian Lance Taylor
2011-01-12  8:45               ` Gidi Nave
2011-01-12 13:50                 ` Jeff Law
2011-01-12 14:23                   ` Gidi Nave
2011-01-12 16:11                   ` Dave Korn
2011-01-16  8:42                     ` Gidi Nave
2011-01-11 15:34     ` Jeff Law

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