Re: Decimal Review Result and Summary.

From: Peter Dimov (pdimov_at_[hidden])
Date: 2025-02-01 20:22:24

Christopher Kormanyos wrote:
> NO: We will NOT be able to* No, we will not be able to meet the factor of 10
> speed exhibited by one particular architecture-specific library.

I must be missing something here, because when I look at

https://www.netlib.org/misc/intel/

which is linked from

https://www.intel.com/content/www/us/en/developer/articles/tool/intel-decimal-floating-point-math-library.html

I don't see anything architecture-specific in the library, everything looks like portable C.

I'm also not sure why this library would be so much faster, because the number format
seems to be standard IEEE BID

https://github.com/featuremine/IntelRDFPMathLib/blob/edda5420528167b14b775cc871e673d561a03da9/LIBRARY/src/bid_internal.h#L2263-L2297
https://github.com/featuremine/IntelRDFPMathLib/blob/edda5420528167b14b775cc871e673d561a03da9/LIBRARY/src/bid_internal.h#L772-L783

and when I look at the comparison

https://github.com/featuremine/IntelRDFPMathLib/blob/edda5420528167b14b775cc871e673d561a03da9/LIBRARY/src/bid32_compare.c#L37

I see nothing that could possibly explain an order of magnitude difference in performance.

Am I looking at the wrong thing?