[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH] df: new option: --total (-c) to produce grand total (in the

From: Ralf Wildenhues
Subject: Re: [PATCH] df: new option: --total (-c) to produce grand total (in the same way as du)
Date: Thu, 4 Sep 2008 09:38:33 +0200
User-agent: Mutt/1.5.18 (2008-07-21)


> Bruno Haible <address@hidden> wrote:
> > Jim Meyering wrote:
> >
> >>> Some of the changes (& => &&) are unconditional improvements, imho.
> >
> > I disagree. The & => && change inserts a conditional branch into the control
> > flow, with the potential to save a single memory access. I count ca. 2 CPU
> > cycles for a memory access and ca. 8 CPU cycles for a conditional jump,
> > therefore I would say that the change slows down the program a bit.

For what little it's worth, this code cycle argument does not take into
account the optimization features of recent GCC versions AFAIK.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]