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From: Andreas Schwab <schwab@suse.de>
To: Paul Schlie <schlie@comcast.net>
Cc: <gcc@gcc.gnu.org>
Subject: Re: warning: right shift count >= width of type
Date: Tue, 30 Nov 2004 01:50:00 -0000	[thread overview]
Message-ID: <jeoehg4246.fsf@sykes.suse.de> (raw)
In-Reply-To: <BDD11A9E.815E%schlie@comcast.net> (Paul Schlie's message of "Mon, 29 Nov 2004 18:27:42 -0500")

Paul Schlie <schlie@comcast.net> writes:

> It likely needs to define what (x << z) means if:
>
> - z lesser-or-equal-to 0, [i.e. does (x << -1) == (x >> 1) ?]

Since left and right shift are usually separate insns this would result in
a runtime penalty.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

  reply	other threads:[~2004-11-30  0:22 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-11-29 23:49 Paul Schlie
2004-11-30  1:50 ` Andreas Schwab [this message]
  -- strict thread matches above, loose matches on Subject: below --
2004-11-30  4:23 Paul Schlie
2004-11-29 16:30 Dave Korn
2004-11-29 16:33 ` Nathan Sidwell
2004-11-29 17:01 ` Andrew Haley
2004-11-29 17:12 ` Dale Johannesen
2004-11-29 17:14   ` Dave Korn
2004-11-29 17:26     ` Andrew Haley
2004-11-29 18:29       ` Peter Barada
2004-11-29 18:53         ` Dave Korn
2004-11-29 18:52       ` Dave Korn
2004-11-29 19:09         ` Andrew Haley
2004-11-29 19:17           ` Dale Johannesen
2004-11-29 19:54             ` Dave Korn
2004-11-29 17:38     ` Chris Jefferson
2004-11-29 18:46       ` Dave Korn
2004-11-29 19:19         ` Chris Jefferson
2004-11-29 19:46           ` Dave Korn

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