Fix ldbl-128 logl for subnormals (bug 16338).

This patch fixes bug 16338, ldbl-128 logl not handling subnormals
(with consequent inaccuracy for lgammal as well).  The fix is simply
to use __frexpl when determining the exponent, as done already in
log2l and log10l.  Given the lack of testing of small arguments to any
of the log* functions, appropriate tests are added for all of them.

Tested x86_64 and x86 and ulps updated accordingly, and spot tests
also run for mips64 to confirm the ldbl-128 fix.

Note that while this fixes lgammal inaccuracy for small positive
arguments, I suspect that there will still be problems with spurious
underflows in that case.

	* sysdeps/ieee754/ldbl-128/e_logl.c (__ieee754_logl): Use __frexpl
	to determine exponent and adjust argument to have exponent of -1.
	* math/auto-libm-test-in: Add more tests of log, log10, log1p and
	log2.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/x86_64/fpu/libm-test-ulps: Update.

1 files changed, 1 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 7886834864..fa19722fce 100644
--- a/NEWS
+++ b/NEWS
@@ -22,7 +22,7 @@ Version 2.19
   15988, 15997, 16032, 16034, 16036, 16037, 16038, 16041, 16055, 16071,
   16072, 16074, 16077, 16078, 16103, 16112, 16143, 16144, 16146, 16150,
   16151, 16153, 16167, 16172, 16195, 16214, 16245, 16271, 16274, 16283,
-  16289, 16314, 16316, 16330.
+  16289, 16314, 16316, 16330, 16338.
 
 * The public headers no longer use __unused nor __block.  This change is to
   support compiling programs that are derived from BSD sources and use