ARM bare-metal programming in D (cont) - volatile

[Johannes Pfau]

Am Thu, 24 Oct 2013 14:04:44 +0100
schrieb Iain Buclaw <ibuclaw at ubuntu.com>:

> On 24 October 2013 12:10, John Colvin
> <john.loughran.colvin at gmail.com> wrote:
> > On Thursday, 24 October 2013 at 09:43:51 UTC, Iain Buclaw wrote:
> >>>>
> >>>> 'shared' guarantees that all reads and writes specified in
> >>>> source code happen in the exact order specified with no omissions

Does this include writes to non-shared data? For example:
------------------------------------
shared int x;
int y;

void func()
{
    x = 0;
    y = 3;  //Can the compiler move this assignment?
    x = 1;
}
------------------------------------

So there's no additional overhead (in code / instructions emitted) when
using shared instead of volatile in code like this? And this is valid
code with shared (assuming reading/assigning to x is atomic)?
------------------------------------
volatile bool x = false;

void waitForX()
{
    while(!x){}
}

__interrupt(X) void x_interrupt()
{
    x = true;
}
------------------------------------