Bruce Evans 51f86873af Use double precision for z and thus for the entire calculation of ... exp2(i/TBLSIZE) * p(z) instead of only for the final multiplication and addition. This fixes the code to match the comment that the maximum error is 0.5010 ulps (except on machines that evaluate float expressions in extra precision, e.g., i386's, where the evaluation was already in extra precision). Fix and expand the comment about use of double precision. The relative roundoff error from evaluating p(z) in non-extra precision was about 16 times larger than in exp2() because the interval length is 16 times smaller. Its maximum was at least P1 * (1.0 ulps) * max(|z|) ~= log(2) * 1.0 * 1/32 ~= 0.0217 ulps (1.0 ulps from the addition in (1 + P1*z) with a cancelation error when z ~= -1/32). The actual final maximum was 0.5313 ulps, of which 0.0303 ulps must have come from the additional roundoff error in p(z). I can't explain why the additional roundoff error was almost 3/2 times larger than the rough estimate.		2008-02-11 05:20:02 +00:00
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amd64	Implement rintl(), nearbyintl(), lrintl(), and llrintl().	2008-01-14 02:12:07 +00:00
arm	Use C comments since we now preprocess these files with CPP.	2007-04-29 14:05:22 +00:00
bsdsrc	Fix tgamma() on some special args:	2007-05-02 15:24:49 +00:00
i387	Implement rintl(), nearbyintl(), lrintl(), and llrintl().	2008-01-14 02:12:07 +00:00
ia64	Use C comments since we now preprocess these files with CPP.	2007-04-29 14:05:22 +00:00
ld80	Use a better method of scaling by 2**k. Instead of adding to the	2008-02-07 03:17:05 +00:00
ld128	Use a better method of scaling by 2**k. Instead of adding to the	2008-02-07 03:17:05 +00:00
man	Introduce a new log(3) manpage and move the relevant functions there.	2008-01-18 21:43:00 +00:00
powerpc	Use C comments since we now preprocess these files with CPP.	2007-04-29 14:05:22 +00:00
sparc64	Use C comments since we now preprocess these files with CPP.	2007-04-29 14:05:22 +00:00
src	Use double precision for z and thus for the entire calculation of	2008-02-11 05:20:02 +00:00
Makefile	Hook up exp2l() and related docs to the build.	2008-01-18 21:43:10 +00:00
Symbol.map	Hook up exp2l() and related docs to the build.	2008-01-18 21:43:10 +00:00