Re: __asm__ usage ????

[Erik Mouw <J.A.K.Mouw@ITS.TUDelft.NL>]

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
WWW: http://www-ict.its.tudelft.nl/~erik/