Date: Wed, 3 Mar 2004 23:30:19 -0800 From: Chris Pressey <cpressey@catseye.mine.nu> To: chungwei Hsiung <skuma17@yahoo.com> Cc: freebsd-questions@freebsd.org Subject: Re: one simple question Message-ID: <20040303233019.1bd37b4a.cpressey@catseye.mine.nu> In-Reply-To: <20040303181343.0fafed01@bear.bflony.adelphia.net> References: <20040303181343.0fafed01@bear.bflony.adelphia.net>
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On Wed, 3 Mar 2004 18:13:43 +0000 chungwei Hsiung <skuma17@yahoo.com> wrote: > Hello.. > I have a simple question, but I am not sure what the answer is. If > anyone can possibly help me, it is really appreciated. I compile a > test C file. I notice there are a few lines at the beginning of the > assembly code. I want to know what it means, but can't figure out > one of them. Can anyone tell me what the following line does please? > > and $0xfffffff0,%esp > > best regards > Chungwei Hi Chungwei, I believe that instruction is used to align the stack pointer to a 16-byte boundary, for efficiency. However, this is just a guess, based on some discussions I've seen. I don't know for certain. You may have better luck asking on hackers@freebsd.org. -Chris
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