On Friday 11 June 2010 23:31:57 Dag-Erling Smørgrav wrote:
> Tijl Coosemans <t...@coosemans.org> writes:
>> Dag-Erling Smørgrav <d...@des.no> writes:
>>> #define FORCE_ASSIGN(type, var, value) \
>>> *(volatile type *)&(var) = (value)
>> memset can be optimised away as well. The only way is to declare
>> those variables volatile.
>
> Assigning through a volatile pointer, as in FORCE_ASSIGN(), also
> works, even if the variable itself is not volatile.
Just thought of problem with this macro when var is a pointer. Then
volatile applies to the referenced memory and not the variable. So
you should move the volatile keyword, like so:
#define FORCE_ASSIGN(type, var, value) \
*(type volatile *)&(var) = (value)
And if you can use GNU extensions this can be simplified to:
#define FORCE_ASSIGN(var, value) \
*(typeof(var) volatile *)&(var) = (value)
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