On 9 Nov 2014 08:40, "Maor via D.gnu" <d.gnu@puremagic.com> wrote:
>
> Hi,
>
> I'm trying to compile a program using inline asm with optimizations and I got my inline asm functions thrown out by the optimizer although I declared them as having side effects (by stating a memory clobber).
> I wrote the following toy program to demonstrate the problem:
>
> ----------------------------------------------
>
> import std.stdio;
> import gcc.attribute;
>
> @attribute("forceinline") ulong exchangeAndAdd(shared ulong *counter, ulong addition) {
>       ulong retVal = void; // we don't want it initialized when dmd is used
>       asm {
>         "
>           mov  %2, %0             ;
>           lock                    ;
>           xadd %0, (%1)           ;
>         ":
>         "=&r"(retVal) :
>         "r"(counter), "r"(addition) :

Maybe try:  "=m"(*counter)

The bug is likely in your input/output clobbers, gcc will always optimise against you unless you get the input/output/clobbers precisely correct.

Iain.