Accessing math coprocessor from C#

How can I access math coprocessor from C# code? I would like to make some ca开发者_Python百科lculations on integers as fast as it's possible. I know it's possible under C++ compliers to use Assembler code inside it, but what about .Net?

The JIT compiler knows about the math coprocessor and will use it. What you really want is to use the SIMD engine, not the math coprocessor. This was part of the promise of JIT-compilation, that the runtime could pick the fastest hardware acceleration available on each computer, but I don't think .NET actually does that, at least in v4.

Or are you using the term "math coprocessor" to mean something other than the x87 FPU? There are some FPGA boards marketed as accelerator/coprocessor systems. If that's what you mean, you'll need to consult the programming manual that comes with the particular product. There are no special CPU instructions for accessing those, inline assembler wouldn't be helpful in this case.

For example, the GPU is even faster at math on large datasets than the CPU's SIMD engine, and you can access that from .NET using DirectX Compute Shaders (or p/invoking OpenCL), no assembler required.

I don't think that this would be possible to do directly from managed code. You could still call unmanaged code which does those calculations but whether the cost of interop marshaling is worth it is difficult to say. You will have to minimize it as much as possible and do all the calculations in unmanaged code and do only a single call to minimize overhead.

No, you cannot directly use inline assembler in C# managed code.

Your best bet is to make sure your general approach/algorithm is clean and efficient, and your math operations are clean and efficient, and then rely on the compiler to make efficient use of the available coprocessor.

This is not natively supported by C# as a language, nor .NET as a framework.

If you need that kind of speed or prowess, use something else altogether.

I know this is an old post, but for those coming here for similar reason of speeding up maths operations, for example a large number of vector operations. To get the greatest speed from C# in maths you should convert your formulae to the logarithmic equivalent. This takes some practice, but once you have the idea you can do it with every formulae. Then decide to keep your values in log form, only converting to human readable form for those values the user needs to see.

The reason logs work faster is because they are all addition and subtraction (subtraction just being the addition of a compliment number), your processors can do these in large numbers with ease.

If you have not done this sort of maths before there are lessons online that will lead you through it, it has a learning curve but for maths/graphics programmers the learning curve is worth it.