InterlockedAdd on x86

[FoxMcCloud]

I was looking at InterlockedAdd()'s documentation ( http://msdn.microsoft.com/en-us/library/ms683504(VS.85).aspx ), and I noticed that it's only available on IPF (IA-64). Is there any technical reason for that? AFAIK, "lock add a, b" is supported on all pentium processors that meet the minimum requirements for Windows...

 

[Npl]

No idea, but InterlockedExchangeAdd does the same?

 

[FoxMcCloud]

Yeah, I know that - my question wasn't asking for a replacement for it, it's more being interested in WHY did they choose not to implement it on x86? I can roll up my own version in assembly, but I wanted to know whether there was a valid reason for that.