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-rw-r--r--ChangeLog10
-rw-r--r--NEWS4
-rw-r--r--math/libm-test.inc3
-rw-r--r--sysdeps/ieee754/ldbl-96/s_tanhl.c2
4 files changed, 16 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index 3a2ab448bf..e862a2c02b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2001-06-19  Andreas Jaeger  <aj@suse.de>
+
+	* sysdeps/ieee754/ldbl-128/s_tanhl.c: New file.
+
+	* math/libm-test.inc (tanh_test): Test for 2^-56.
+
+	* sysdeps/ieee754/ldbl-96/s_tanhl.c (__tanhl): Make sure result
+	equals argument when x < 2^-55.
+	Patches by Stephen L. Moshier <moshier@na-net.ornl.gov>.
+
 2001-06-17  Alan Modra  <amodra@bigpond.net.au>
 
 	* sysdeps/hppa/dl-machine.h (elf_machine_rela): handle relocs
diff --git a/NEWS b/NEWS
index 2c9046a9fc..38694a47fd 100644
--- a/NEWS
+++ b/NEWS
@@ -8,8 +8,8 @@ Please send GNU C library bug reports using the `glibcbug' script to
 
 Version 2.2.4
 
-* Stephen Moshier implemented cosh, expm1, log1p, acos, sinh for the
-  128-bit long double format.
+* Stephen Moshier implemented cosh, expm1, log1p, acos, sinh, tanh for
+  the 128-bit long double format.
 
 * Bruno Haible updated all the code handling Unicode in some form to
   support Unicode 3.1.
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 481c395643..2c3a3f6ffa 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -3975,6 +3975,9 @@ tanh_test (void)
   TEST_f_f (tanh, 1.0L, 0.7615941559557648881194582826047935904L);
   TEST_f_f (tanh, -1.0L, -0.7615941559557648881194582826047935904L);
 
+  /* 2^-56  */
+  TEST_f_f (tanh, 1.387778780781445675529539585113525390625e-17L, 1.387778780781445675529539585113525390625e-17L);
+  
   END (tanh);
 }
 
diff --git a/sysdeps/ieee754/ldbl-96/s_tanhl.c b/sysdeps/ieee754/ldbl-96/s_tanhl.c
index 5c0ac9a95d..45cea903e3 100644
--- a/sysdeps/ieee754/ldbl-96/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-96/s_tanhl.c
@@ -78,7 +78,7 @@ static long double one=1.0, two=2.0, tiny = 1.0e-4900L;
 	    if ((ix|j0|j1) == 0)
 		return x;		/* x == +- 0 */
 	    if (ix<0x3fc8)		/* |x|<2**-55 */
-		return x*(one+x);	/* tanh(small) = small */
+		return x*(one+tiny);	/* tanh(small) = small */
 	    if (ix>=0x3fff) {	/* |x|>=1  */
 		t = __expm1l(two*fabsl(x));
 		z = one - two/(t+two);