Is there a compiler memory barrier for a single variable?

Question

Compiler memory barriers has the effect among other things to force the compiler to make sure all stack variables that are cached in registers are written t

Answer 1

I guess you can achieve it by specifying your variable in the list of output values of asm:

__asm__ __volatile__ ("" : "=r" (x) : : )

See Extended Asm for some information.

UPD.

It may be better to use "g" constraint instead of "r" as more permissive.

__asm__ __volatile__ ("" : "=g" (x) : : )

Also, I've found another great howto for inline assembly.