Use asm functions in fdlibm

[ViralBShah]

The base fdlibm does not have arch specific assembly code. The freebsd lib/msun is a derivative of fdlibm, which does seem to have these. We need to check if speed is indeed better, and if accuracy remains the same, and if so, use freebsd msun instead of fdlibm.

http://svnweb.freebsd.org/base/release/8.2.0/lib/msun/

[JeffBezanson]

I'm fairly sure we want to use all the libm64 functions in place of their corresponding fdlibm ones on x86-64. I also know we do NOT want to use the trig functions in libm387, but some of the others there might be useful.

[ViralBShah]

What's the problem with the libm387 trig functions? Is it accuracy, or is there a better way to do it on x86-64?

-viral

On Jun 16, 2011, at 11:37 PM, JeffBezanson wrote:

I'm fairly sure we want to use all the libm64 functions in place of their corresponding fdlibm ones on x86-64. I also know we do NOT want to use the trig functions in libm387, but some of the others there might be useful.

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#14 (comment)

[JeffBezanson]

Accuracy. Intel has only designed them to support an argument range of +-2^63. They are also no faster than a good all-software implementation on a modern cpu.

[JeffBezanson]

OK, we know we want the libm64 functions, especially sqrt if nothing else. sqrt is important.

[JeffBezanson]

Now an openlibm issue.