Hi,
I have following snippet of code.
Code A
__asm__ __volatile__(
" lock ;\n"
" addl %1,%0 ;\n"
: "=m" (my_var)
: "ir" (my_int), "m" (my_var)
: /* no clobber-list */
);
Code B
__asm__ __volatile__( "decl %0; sete %1"
: "=m" (my_var), "=q" (cond)
: "m" (my_var)
: "memory"
);
In Code A memory contents are getting updated. And in Code B memory
contents and 'cond' var are getting updated.
In Code B in cobbler column 'memory' is used to indicate that this
code modifies memory contents. But where as in Code A it was not
mentioned
Is is not that Code A is wrong, for not mentioning cobbler list
'memory' to indicate memory contents are getting updated.
Please rectify me, if I am wrong.
Also, what does '+m' constraint mean, if I use in inline assembly.
--
Regards,
Sri.
_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
