Re: __asm__ usage ????

Erik Mouw
2001-08-10T23:28:31Z

On Fri, Aug 10, 2001 at 12:50:04PM -0700, Raghava Raju wrote:

> I want some basic insights into assembly level code
> emmbedded in C language. Following is the code of
> PowerPc ambedded in C languagge:
>
> unsigned long old,mask, *p;
>
> __asm__ __volatile__(SMP_WMB "\
> 1: lwarx %0,0,%3
> andc %0,%0,%2
> stwcx %0,0,%3
> bne 1b"
> SMP_MB
> : "=&r" (old), "=m" (*p)
> : "r" (mask), "r" (p), "m" (*p)
> : "cc");
>
> 1) what does these things denote: __volatile__,
> SMP_WMB, SMP_MB, "r","=&r","=m",
> "cc" and 1: .

>From http://www.kernelnewbies.org/links/ :

http://www-106.ibm.com/developerworks/linux/library/l-ia.html
http://www.uwsg.indiana.edu/hypermail/linux/kernel/9804.2/0953.html

Erik

--
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031, 2600 GA Delft, The Netherlands
Phone: +31-15-2783635 Fax: +31-15-2781843 Email: J.A.K.Mouw@its.tudelft.nl
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