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Re: Observations on LLSC and SMP

To: Daniel Jacobowitz <dan@debian.org>
Subject: Re: Observations on LLSC and SMP
From: Ed Martini <martini@c2micro.com>
Date: Fri, 25 Mar 2005 14:46:04 -0800
Cc: linux-mips@linux-mips.org
In-reply-to: <20050325193759.GA23046@nevyn.them.org>
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Daniel Jacobowitz wrote:

On Fri, Mar 25, 2005 at 11:24:05AM -0800, Ed Martini wrote:
1. If the first part of the if were an ifdef instead it would result in a code size reduction as well as a runtime performance gain.

You should spend a little time playing with an optimizing compiler. They're capable of working out when a condition will always be false.
Yes, but in the case where R10000_LLSC_WAR is true, but cpu_has_llsc returns false there are still two wasted tests, and two blocks of code that the compiler can't optimize out.



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