This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: optimisation question

From: Robert Dewar <dewar at adacore dot com>
To: Dave Korn <dave dot korn at artimi dot com>
Cc: 'Andreas Schwab' <schwab at suse dot de>,"'Remy X.O. Martin'" <vsxo at hotmail dot com>,'Joe Buck' <Joe dot Buck at synopsys dot COM>, gcc at gcc dot gnu dot org
Date: Wed, 02 Feb 2005 11:28:20 -0500
Subject: Re: optimisation question
References: <NUTMEG4yfQyhnmPkSiL0000048f@NUTMEG.CAM.ARTIMI.COM>

Dave Korn wrote:

  I think Andreas' point there is just that, if one accepts that comma and
semicolon are equivalent in this case, then one must also accept that the two
original examples

a = b, c = d, e = f;

and
    a = b; c = d; e = f;

become formally identical, thereby showing that it's meaningless to suggest one
may be more optimal than the other.


Well being formally identical does not guarantee identical code. Presumably
this peculiar advice came from a compiler where they were treated in identical
manner. Nothing in the standard requires identical code in these two cases.

References:
- RE: optimisation question
  - From: Dave Korn

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]