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AMD Previews New Processor Extensions
An anonymous reader writes "It has been all over the news today: AMD announced the first of its Extensions for Software Parallelism, a series of x86 extensions to make parallel programming easier. The first are the so-called 'lightweight profiling extensions.' They would give software access to information about cache misses and retired instructions so data structures can be optimized for better performance. The specification is here (PDF). These extensions have a much wider applicability than just parallel programming — they could be used to accelerate Java, .Net, and dynamic optimizers." AMD gave no timeframe for when these proposed extensions would show up in silicon.
Well we had the 68000 family which had much better instruction set then the X86.
We have the Power and PowerPC which had a much better instruction set than the X86.
We have the ARM which is a much better instruction set then the X86.
We have the MIPS which is pretty nice.
And we had the Alpha and still do for a little while longer.
The problem with all of them is that they didn't run X86 code. Intel and AMD both made so much money from selling billions of CPUs that they could plow a lot of money into making the X86 the fastest pig with lipstick that the world has ever seen.
What made the IA-64 such a disaster was that it was slow running X86 code.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Not again.
Why is this nonsense still perpetuated? The instruction set is irrelevant - it's just an interface to tell the processor what to do. Internally, Barcelona is a very nice RISC core capable of doing so many things at once its insane. The only thing that performs better is a GPU, and that's only because they're thrown at embarassingly parallel problems. The fastest general purpose CPUs come from Intel and AMD, and it has nothing to do with instruction set.
AMD64, and the new Core2 and Barcelona chips are very nice chips. 16 64-bit registers, 16 128-bit registers, complete IEEE-754 floating point support, integer and floating-point SIMD instructions, out-of-order execution, streaming stores and hardware prefetch. Add to that multiple cores with very fast busses, massive caches - with multichip cache coherency - and the ability to run any code compiled in the last 25 years. What's not to like?
Performance counters could be used by JITs to generate more optimized code. I wonder which programming languages use JITs...