Messages in this thread | | | Subject | Re: [PATCH] no need to check for NULL before calling kfree() -fs/ext2/ | Date | Sat, 26 Mar 2005 22:00:40 -0400 | From | Horst von Brand <> |
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Marcin Dalecki <martin@dalecki.de> said: > On 2005-03-27, at 00:21, linux-os wrote: > > Always, always, a call will be more expensive than a branch > > on condition.
Wrong.
> > It's impossible to be otherwise.
Many, many counterexamples say otherwise...
> > A call requires > > that the return address be written to memory (the stack),
Not necesarily right now, it can be done at leisure later on while doing other stuff.
> > using register indirection (the stack-pointer).
So what? The stack pointer is surely special. Modern programming languages (and programming styles) encourage many calls, so this is very heavily optimized.
> Needless to say that there are enough architectures out there, which > don't even have something like an explicit call as separate assembler > instruction...
The mechanism exists somehow. -- Dr. Horst H. von Brand User #22616 counter.li.org Departamento de Informatica Fono: +56 32 654431 Universidad Tecnica Federico Santa Maria +56 32 654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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