Replies to post #3580 on Advanced Micro Devices Inc (AMD)

[jhalada]

wbmw,

Microsoft will release an x86-64 compiler at some point, but I wouldn't hold my breath.

There are 2 parts: C++ compiler and .NET engine (which enables all .NET apps to become 64 bit apps). My expectation would be that both would be released in approximately the same timeframe as the AMD64 OS. Probably within a year from now.

They are notoriously slow at working in architecture optimizations into their compiler.

If there was a huge demand for architecture optimizations, I am sure MSFT would have responded. But the issue is complicated since the target machines out there range from Pentiums (P5), P6, P68, K6, K7 (all flavors) of each, some Cyrix / Via, each requires different optimization. So it is a huge can of worms for vast majority of developers, and they rather keep it closed.

But a for a small percentage of developers, the issue is extremely important. Intel is already serving this boutigue crowd, showering the product with subsidies. I don't think MSFT sees any threat here from Intel, so the optimization market is safely ignored by MSFT.

As for their x86-64 support, they will do the minimum, plus any low hanging fruit that happens to fit within their schedule.

I don't expect any more, but even the minimum is a lot, since it involves efficient use of the extra the extra registers (the biggest performance booster). Also, compiling for AMD64 target, it there is an assurance that the machine has all of the MMX, 3DNow, SSE, SSE2, so these instructions can be used readily, rather than being a can of worms. AMD64 is one architecture, X86-32 is a dozen of different processor architectures.

I don't expect MSFT to go out of their way, but I am assuming (my assembly skills are somewhere from rusty to non-existent) that any floating point instruction can be dispatched to processor through SSE-2 mechanism rather than FP, which is more efficient. So the AMD64 compiler can completely eliminate FP instructions. (correct me if I am wrong).

By the way, my previous post had absolutely nothing to do with SPECint.

That was a confusion on my part.

Joe

[dougSF30]

wbmw, Re: They are notoriously slow at working in architecture optimizations into their compiler.

Well, for the Itanium, at least, delays should have been expected. With a much less alien target like AMD64 on the Opteron, it really shouldn't be that much effort. I'm sure the beta is in many hands by now.

Doug

[fyodor]

wbmw: As for their x86-64 support, they will do the minimum, plus any low hanging fruit that happens to fit within their schedule. If you are expecting anything close to the level of optimizations that Intel puts into their compiler, you will be very disappointed.

You are assuming that AMD doesn't have a team of software folks working closely with Microsoft to optimize for x86-64.

I believe you are incorrect in that assumption.

-fyo