MKL vs Microsoft exp() function

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Quote:

David C. wrote:

Quote:

iliyapolakwrote:

Can you post disassembly of exp()?

I'm not sure I should do that, it might incur the wrath of Microsoft as it's their copyright. You can disassemble it yourself quite easily if you run the test program I gave under the debugger and step into exp().

Sorry for asking this.

>>>However, under some conditions they get multiplied,>>>

Does the multiplication of  32/64 bit difference of results is a mandatory part of your code or is it done only for testing ppurpose?

Quote:

iliyapolak wrote:

>>>However, under some conditions they get multiplied,>>>

Does the multiplication of  32/64 bit difference of results is a mandatory part of your code or is it done only for testing ppurpose?

It's a necessary part of the code. It happens when we take the difference between two similar computations that use exp(), for example when calculating the derivative of a function by bumping. We know there will be a loss or precision when we do this, but as I explained before, the problem for us is lack of consistency between the two builds, not lack of precision.

What about single precision results did they differ between the 32 and 64 bit libraries?Do you need double precision in your code?

We use double precision only, so I haven't tried the single-precision versions.

>>...as I explained before, the problem for us is lack of consistency between the two builds, not lack of precision...

Could you post results for comparison from both builds?

Unfortunately, these generic explanations are Not helping. Several IDZ members responed to your problem and some of them, including me, are trying to help you absolutely for free because a problem looks very interesting. I provided you with lots of examples and results and I didn't see follow ups.

Also, if you think some details can not be released to a public thread then you need to proceed with a request to Intel Premier Support.

Does your application by design demand double precision computation domain?

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