x86 equivalent for LWARX and STWCX

Question

I\'m looking for an equivalent of LWARX and STWCX (as found on the PowerPC processors) or a way to implement similar functionality on the x86 platform. Also, where would be

Answer 1

You're probably looking for the cmpxchg family of instructions.

You'll need to precede these with a lock instruction to get equivalent behaviour.

Have a look here for a quick overview of what's available.

You'll likely end up with something similar to this:

mov ecx,dword ptr [esp+4]
mov edx,dword ptr [esp+8]
mov eax,dword ptr [esp+12]
lock cmpxchg dword ptr [ecx],edx
ret 12

You should read this paper...

Edit

In response to the updated question, are you looking to do something like the Boost shared_ptr? If so, have a look at that code and the files in that directory - they'll definitely get you started.