Fix tanh missing underflows (bug 16520).

Similar to various other bugs in this area, some tanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #16520]
	* sysdeps/ieee754/dbl-64/s_tanh.c: Include <float.h>.
	(__tanh): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/flt-32/s_tanhf.c: Include <float.h>.
	(__tanhf): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128/s_tanhl.c: Include <float.h>.
	(__tanhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: Include <float.h>.
	(__tanhl): Force underflow exception for arguments with small
	absolute value.
	* sysdeps/ieee754/ldbl-96/s_tanhl.c: Include <float.h>.
	(__tanhl): Force underflow exception for arguments with small
	absolute value.
	* math/auto-libm-test-in: Add more tests of tanh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.

diff --git a/ChangeLog b/ChangeLog
index 3f55c55a1d1bc1a9685c36f1eed1f80045fa3058..dbb7b467f6bd4702288c0ef289299c6ebfddcc74 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,25 @@
+2015-08-13  Joseph Myers  <joseph@codesourcery.com>
+
+       [BZ #16520]
+       * sysdeps/ieee754/dbl-64/s_tanh.c: Include <float.h>.
+       (__tanh): Force underflow exception for arguments with small
+       absolute value.
+       * sysdeps/ieee754/flt-32/s_tanhf.c: Include <float.h>.
+       (__tanhf): Force underflow exception for arguments with small
+       absolute value.
+       * sysdeps/ieee754/ldbl-128/s_tanhl.c: Include <float.h>.
+       (__tanhl): Force underflow exception for arguments with small
+       absolute value.
+       * sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: Include <float.h>.
+       (__tanhl): Force underflow exception for arguments with small
+       absolute value.
+       * sysdeps/ieee754/ldbl-96/s_tanhl.c: Include <float.h>.
+       (__tanhl): Force underflow exception for arguments with small
+       absolute value.
+       * math/auto-libm-test-in: Add more tests of tanh.
+       * math/auto-libm-test-out: Regenerated.
+       * sysdeps/i386/fpu/libm-test-ulps: Update.
+
 2015-08-13  H.J. Lu  <hongjiu.lu@intel.com>
 
        * sysdeps/x86/cpu-features.c (init_cpu_features): Call

diff --git a/NEWS b/NEWS
index ea8bb6d7ca34a96d6ff76a09576d0dbec7b6db3f..5ca3de83532f758f6ea09d2cbbffc79b76c44b3c 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -9,8 +9,8 @@ Version 2.23
 
 * The following bugs are resolved with this release:
 
-  16517, 16519, 16734, 17905, 18086, 18265, 18480, 18525, 18618, 18647,
-  18661, 18674, 18778, 18781, 18787, 18789, 18790, 18820.
+  16517, 16519, 16520, 16734, 17905, 18086, 18265, 18480, 18525, 18618,
+  18647, 18661, 18674, 18778, 18781, 18787, 18789, 18790, 18820.
 
 \f
 Version 2.22

diff --git a/math/auto-libm-test-in b/math/auto-libm-test-in
index c32e4369058a12db15261316aa3aba417d4da9e5..b14146e2b6428df4df0de5b1b1efe0311478dfee 100644 (file)
--- a/math/auto-libm-test-in
+++ b/math/auto-libm-test-in
@@ -2779,6 +2779,10 @@ tanh -0x2.6082fp-4
 tanh 0xe.05031p-16
 tanh 0x3.c80eaa7adaa3p-4
 tanh 0x2.00f9857616524p-4
+tanh min
+tanh -min
+tanh min_subnorm
+tanh -min_subnorm
 
 tgamma 0.5
 tgamma -0.5

diff --git a/math/auto-libm-test-out b/math/auto-libm-test-out
index b4114be3d8ca56bb248db813940ebf68a6b5ae72..4d8bcf2f0855938a7009195d687f571c4d9699f6 100644 (file)
--- a/math/auto-libm-test-out
+++ b/math/auto-libm-test-out
@@ -205177,6 +205177,322 @@ tanh 0x2.00f9857616524p-4
 = tanh tonearest ldbl-128ibm 0x2.00f9857616524p-4L : 0x1.fe4f3a8e0515344ff794387d93p-4L : inexact-ok
 = tanh towardzero ldbl-128ibm 0x2.00f9857616524p-4L : 0x1.fe4f3a8e0515344ff794387d928p-4L : inexact-ok
 = tanh upward ldbl-128ibm 0x2.00f9857616524p-4L : 0x1.fe4f3a8e0515344ff794387d93p-4L : inexact-ok
+tanh min
+= tanh downward flt-32 0x4p-128f : 0x3.fffff8p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest flt-32 0x4p-128f : 0x4p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero flt-32 0x4p-128f : 0x3.fffff8p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh upward flt-32 0x4p-128f : 0x4p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh downward dbl-64 0x4p-128 : 0x3.ffffffffffffep-128 : inexact-ok
+= tanh tonearest dbl-64 0x4p-128 : 0x4p-128 : inexact-ok
+= tanh towardzero dbl-64 0x4p-128 : 0x3.ffffffffffffep-128 : inexact-ok
+= tanh upward dbl-64 0x4p-128 : 0x4p-128 : inexact-ok
+= tanh downward ldbl-96-intel 0x4p-128L : 0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh tonearest ldbl-96-intel 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh towardzero ldbl-96-intel 0x4p-128L : 0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh upward ldbl-96-intel 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh downward ldbl-96-m68k 0x4p-128L : 0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh tonearest ldbl-96-m68k 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh towardzero ldbl-96-m68k 0x4p-128L : 0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh upward ldbl-96-m68k 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh downward ldbl-128 0x4p-128L : 0x3.fffffffffffffffffffffffffffep-128L : inexact-ok
+= tanh tonearest ldbl-128 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh towardzero ldbl-128 0x4p-128L : 0x3.fffffffffffffffffffffffffffep-128L : inexact-ok
+= tanh upward ldbl-128 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh downward ldbl-128ibm 0x4p-128L : 0x3.ffffffffffffffffffffffffffp-128L : inexact-ok
+= tanh tonearest ldbl-128ibm 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh towardzero ldbl-128ibm 0x4p-128L : 0x3.ffffffffffffffffffffffffffp-128L : inexact-ok
+= tanh upward ldbl-128ibm 0x4p-128L : 0x4p-128L : inexact-ok
+= tanh downward dbl-64 0x4p-1024 : 0x3.ffffffffffffcp-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest dbl-64 0x4p-1024 : 0x4p-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero dbl-64 0x4p-1024 : 0x3.ffffffffffffcp-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh upward dbl-64 0x4p-1024 : 0x4p-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-96-intel 0x4p-1024L : 0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh tonearest ldbl-96-intel 0x4p-1024L : 0x4p-1024L : inexact-ok
+= tanh towardzero ldbl-96-intel 0x4p-1024L : 0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh upward ldbl-96-intel 0x4p-1024L : 0x4p-1024L : inexact-ok
+= tanh downward ldbl-96-m68k 0x4p-1024L : 0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh tonearest ldbl-96-m68k 0x4p-1024L : 0x4p-1024L : inexact-ok
+= tanh towardzero ldbl-96-m68k 0x4p-1024L : 0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh upward ldbl-96-m68k 0x4p-1024L : 0x4p-1024L : inexact-ok
+= tanh downward ldbl-128 0x4p-1024L : 0x3.fffffffffffffffffffffffffffep-1024L : inexact-ok
+= tanh tonearest ldbl-128 0x4p-1024L : 0x4p-1024L : inexact-ok
+= tanh towardzero ldbl-128 0x4p-1024L : 0x3.fffffffffffffffffffffffffffep-1024L : inexact-ok
+= tanh upward ldbl-128 0x4p-1024L : 0x4p-1024L : inexact-ok
+= tanh downward ldbl-128ibm 0x4p-1024L : 0x3.ffffffffffffcp-1024L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128ibm 0x4p-1024L : 0x4p-1024L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128ibm 0x4p-1024L : 0x3.ffffffffffffcp-1024L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128ibm 0x4p-1024L : 0x4p-1024L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-intel 0x4p-16384L : 0x3.fffffffffffffff8p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-96-intel 0x4p-16384L : 0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-96-intel 0x4p-16384L : 0x3.fffffffffffffff8p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-96-intel 0x4p-16384L : 0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-96-m68k 0x4p-16384L : 0x3.fffffffffffffffcp-16384L : inexact-ok
+= tanh tonearest ldbl-96-m68k 0x4p-16384L : 0x4p-16384L : inexact-ok
+= tanh towardzero ldbl-96-m68k 0x4p-16384L : 0x3.fffffffffffffffcp-16384L : inexact-ok
+= tanh upward ldbl-96-m68k 0x4p-16384L : 0x4p-16384L : inexact-ok
+= tanh downward ldbl-128 0x4p-16384L : 0x3.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-128 0x4p-16384L : 0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-128 0x4p-16384L : 0x3.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-128 0x4p-16384L : 0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-96-intel 0x2p-16384L : 0x1.fffffffffffffff8p-16384L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-intel 0x2p-16384L : 0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-intel 0x2p-16384L : 0x1.fffffffffffffff8p-16384L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-intel 0x2p-16384L : 0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-m68k 0x2p-16384L : 0x1.fffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-96-m68k 0x2p-16384L : 0x2p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-96-m68k 0x2p-16384L : 0x1.fffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-96-m68k 0x2p-16384L : 0x2p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-128 0x2p-16384L : 0x1.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 0x2p-16384L : 0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 0x2p-16384L : 0x1.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 0x2p-16384L : 0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh downward dbl-64 0x8p-972 : 0x7.ffffffffffffcp-972 : inexact-ok
+= tanh tonearest dbl-64 0x8p-972 : 0x8p-972 : inexact-ok
+= tanh towardzero dbl-64 0x8p-972 : 0x7.ffffffffffffcp-972 : inexact-ok
+= tanh upward dbl-64 0x8p-972 : 0x8p-972 : inexact-ok
+= tanh downward ldbl-96-intel 0x8p-972L : 0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh tonearest ldbl-96-intel 0x8p-972L : 0x8p-972L : inexact-ok
+= tanh towardzero ldbl-96-intel 0x8p-972L : 0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh upward ldbl-96-intel 0x8p-972L : 0x8p-972L : inexact-ok
+= tanh downward ldbl-96-m68k 0x8p-972L : 0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh tonearest ldbl-96-m68k 0x8p-972L : 0x8p-972L : inexact-ok
+= tanh towardzero ldbl-96-m68k 0x8p-972L : 0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh upward ldbl-96-m68k 0x8p-972L : 0x8p-972L : inexact-ok
+= tanh downward ldbl-128 0x8p-972L : 0x7.fffffffffffffffffffffffffffcp-972L : inexact-ok
+= tanh tonearest ldbl-128 0x8p-972L : 0x8p-972L : inexact-ok
+= tanh towardzero ldbl-128 0x8p-972L : 0x7.fffffffffffffffffffffffffffcp-972L : inexact-ok
+= tanh upward ldbl-128 0x8p-972L : 0x8p-972L : inexact-ok
+= tanh downward ldbl-128ibm 0x8p-972L : 0x7.fffffffffffffffffffffffffcp-972L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-128ibm 0x8p-972L : 0x8p-972L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-128ibm 0x8p-972L : 0x7.fffffffffffffffffffffffffcp-972L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-128ibm 0x8p-972L : 0x8p-972L : inexact-ok underflow-ok errno-erange-ok
+tanh -min
+= tanh downward flt-32 -0x4p-128f : -0x4p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest flt-32 -0x4p-128f : -0x4p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero flt-32 -0x4p-128f : -0x3.fffff8p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh upward flt-32 -0x4p-128f : -0x3.fffff8p-128f : inexact-ok underflow-ok errno-erange-ok
+= tanh downward dbl-64 -0x4p-128 : -0x4p-128 : inexact-ok
+= tanh tonearest dbl-64 -0x4p-128 : -0x4p-128 : inexact-ok
+= tanh towardzero dbl-64 -0x4p-128 : -0x3.ffffffffffffep-128 : inexact-ok
+= tanh upward dbl-64 -0x4p-128 : -0x3.ffffffffffffep-128 : inexact-ok
+= tanh downward ldbl-96-intel -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh tonearest ldbl-96-intel -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh towardzero ldbl-96-intel -0x4p-128L : -0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh upward ldbl-96-intel -0x4p-128L : -0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh downward ldbl-96-m68k -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh tonearest ldbl-96-m68k -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh towardzero ldbl-96-m68k -0x4p-128L : -0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh upward ldbl-96-m68k -0x4p-128L : -0x3.fffffffffffffffcp-128L : inexact-ok
+= tanh downward ldbl-128 -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh tonearest ldbl-128 -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh towardzero ldbl-128 -0x4p-128L : -0x3.fffffffffffffffffffffffffffep-128L : inexact-ok
+= tanh upward ldbl-128 -0x4p-128L : -0x3.fffffffffffffffffffffffffffep-128L : inexact-ok
+= tanh downward ldbl-128ibm -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh tonearest ldbl-128ibm -0x4p-128L : -0x4p-128L : inexact-ok
+= tanh towardzero ldbl-128ibm -0x4p-128L : -0x3.ffffffffffffffffffffffffffp-128L : inexact-ok
+= tanh upward ldbl-128ibm -0x4p-128L : -0x3.ffffffffffffffffffffffffffp-128L : inexact-ok
+= tanh downward dbl-64 -0x4p-1024 : -0x4p-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest dbl-64 -0x4p-1024 : -0x4p-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero dbl-64 -0x4p-1024 : -0x3.ffffffffffffcp-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh upward dbl-64 -0x4p-1024 : -0x3.ffffffffffffcp-1024 : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-96-intel -0x4p-1024L : -0x4p-1024L : inexact-ok
+= tanh tonearest ldbl-96-intel -0x4p-1024L : -0x4p-1024L : inexact-ok
+= tanh towardzero ldbl-96-intel -0x4p-1024L : -0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh upward ldbl-96-intel -0x4p-1024L : -0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh downward ldbl-96-m68k -0x4p-1024L : -0x4p-1024L : inexact-ok
+= tanh tonearest ldbl-96-m68k -0x4p-1024L : -0x4p-1024L : inexact-ok
+= tanh towardzero ldbl-96-m68k -0x4p-1024L : -0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh upward ldbl-96-m68k -0x4p-1024L : -0x3.fffffffffffffffcp-1024L : inexact-ok
+= tanh downward ldbl-128 -0x4p-1024L : -0x4p-1024L : inexact-ok
+= tanh tonearest ldbl-128 -0x4p-1024L : -0x4p-1024L : inexact-ok
+= tanh towardzero ldbl-128 -0x4p-1024L : -0x3.fffffffffffffffffffffffffffep-1024L : inexact-ok
+= tanh upward ldbl-128 -0x4p-1024L : -0x3.fffffffffffffffffffffffffffep-1024L : inexact-ok
+= tanh downward ldbl-128ibm -0x4p-1024L : -0x4p-1024L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128ibm -0x4p-1024L : -0x4p-1024L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128ibm -0x4p-1024L : -0x3.ffffffffffffcp-1024L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128ibm -0x4p-1024L : -0x3.ffffffffffffcp-1024L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-intel -0x4p-16384L : -0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-96-intel -0x4p-16384L : -0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-96-intel -0x4p-16384L : -0x3.fffffffffffffff8p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-96-intel -0x4p-16384L : -0x3.fffffffffffffff8p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-96-m68k -0x4p-16384L : -0x4p-16384L : inexact-ok
+= tanh tonearest ldbl-96-m68k -0x4p-16384L : -0x4p-16384L : inexact-ok
+= tanh towardzero ldbl-96-m68k -0x4p-16384L : -0x3.fffffffffffffffcp-16384L : inexact-ok
+= tanh upward ldbl-96-m68k -0x4p-16384L : -0x3.fffffffffffffffcp-16384L : inexact-ok
+= tanh downward ldbl-128 -0x4p-16384L : -0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-128 -0x4p-16384L : -0x4p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-128 -0x4p-16384L : -0x3.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-128 -0x4p-16384L : -0x3.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-96-intel -0x2p-16384L : -0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-intel -0x2p-16384L : -0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-intel -0x2p-16384L : -0x1.fffffffffffffff8p-16384L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-intel -0x2p-16384L : -0x1.fffffffffffffff8p-16384L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-m68k -0x2p-16384L : -0x2p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-96-m68k -0x2p-16384L : -0x2p-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-96-m68k -0x2p-16384L : -0x1.fffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-96-m68k -0x2p-16384L : -0x1.fffffffffffffffcp-16384L : inexact-ok underflow-ok errno-erange-ok
+= tanh downward ldbl-128 -0x2p-16384L : -0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 -0x2p-16384L : -0x2p-16384L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 -0x2p-16384L : -0x1.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 -0x2p-16384L : -0x1.fffffffffffffffffffffffffffcp-16384L : inexact-ok underflow errno-erange-ok
+= tanh downward dbl-64 -0x8p-972 : -0x8p-972 : inexact-ok
+= tanh tonearest dbl-64 -0x8p-972 : -0x8p-972 : inexact-ok
+= tanh towardzero dbl-64 -0x8p-972 : -0x7.ffffffffffffcp-972 : inexact-ok
+= tanh upward dbl-64 -0x8p-972 : -0x7.ffffffffffffcp-972 : inexact-ok
+= tanh downward ldbl-96-intel -0x8p-972L : -0x8p-972L : inexact-ok
+= tanh tonearest ldbl-96-intel -0x8p-972L : -0x8p-972L : inexact-ok
+= tanh towardzero ldbl-96-intel -0x8p-972L : -0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh upward ldbl-96-intel -0x8p-972L : -0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh downward ldbl-96-m68k -0x8p-972L : -0x8p-972L : inexact-ok
+= tanh tonearest ldbl-96-m68k -0x8p-972L : -0x8p-972L : inexact-ok
+= tanh towardzero ldbl-96-m68k -0x8p-972L : -0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh upward ldbl-96-m68k -0x8p-972L : -0x7.fffffffffffffff8p-972L : inexact-ok
+= tanh downward ldbl-128 -0x8p-972L : -0x8p-972L : inexact-ok
+= tanh tonearest ldbl-128 -0x8p-972L : -0x8p-972L : inexact-ok
+= tanh towardzero ldbl-128 -0x8p-972L : -0x7.fffffffffffffffffffffffffffcp-972L : inexact-ok
+= tanh upward ldbl-128 -0x8p-972L : -0x7.fffffffffffffffffffffffffffcp-972L : inexact-ok
+= tanh downward ldbl-128ibm -0x8p-972L : -0x8p-972L : inexact-ok underflow-ok errno-erange-ok
+= tanh tonearest ldbl-128ibm -0x8p-972L : -0x8p-972L : inexact-ok underflow-ok errno-erange-ok
+= tanh towardzero ldbl-128ibm -0x8p-972L : -0x7.fffffffffffffffffffffffffcp-972L : inexact-ok underflow-ok errno-erange-ok
+= tanh upward ldbl-128ibm -0x8p-972L : -0x7.fffffffffffffffffffffffffcp-972L : inexact-ok underflow-ok errno-erange-ok
+tanh min_subnorm
+= tanh downward flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange-ok
+= tanh tonearest flt-32 0x8p-152f : 0x8p-152f : inexact-ok underflow errno-erange-ok
+= tanh towardzero flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange-ok
+= tanh upward flt-32 0x8p-152f : 0x8p-152f : inexact-ok underflow errno-erange-ok
+= tanh downward dbl-64 0x8p-152 : 0x7.ffffffffffffcp-152 : inexact-ok
+= tanh tonearest dbl-64 0x8p-152 : 0x8p-152 : inexact-ok
+= tanh towardzero dbl-64 0x8p-152 : 0x7.ffffffffffffcp-152 : inexact-ok
+= tanh upward dbl-64 0x8p-152 : 0x8p-152 : inexact-ok
+= tanh downward ldbl-96-intel 0x8p-152L : 0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh tonearest ldbl-96-intel 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh towardzero ldbl-96-intel 0x8p-152L : 0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh upward ldbl-96-intel 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh downward ldbl-96-m68k 0x8p-152L : 0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh tonearest ldbl-96-m68k 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh towardzero ldbl-96-m68k 0x8p-152L : 0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh upward ldbl-96-m68k 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh downward ldbl-128 0x8p-152L : 0x7.fffffffffffffffffffffffffffcp-152L : inexact-ok
+= tanh tonearest ldbl-128 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh towardzero ldbl-128 0x8p-152L : 0x7.fffffffffffffffffffffffffffcp-152L : inexact-ok
+= tanh upward ldbl-128 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh downward ldbl-128ibm 0x8p-152L : 0x7.fffffffffffffffffffffffffep-152L : inexact-ok
+= tanh tonearest ldbl-128ibm 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh towardzero ldbl-128ibm 0x8p-152L : 0x7.fffffffffffffffffffffffffep-152L : inexact-ok
+= tanh upward ldbl-128ibm 0x8p-152L : 0x8p-152L : inexact-ok
+= tanh downward dbl-64 0x4p-1076 : 0x0p+0 : inexact-ok underflow errno-erange-ok
+= tanh tonearest dbl-64 0x4p-1076 : 0x4p-1076 : inexact-ok underflow errno-erange-ok
+= tanh towardzero dbl-64 0x4p-1076 : 0x0p+0 : inexact-ok underflow errno-erange-ok
+= tanh upward dbl-64 0x4p-1076 : 0x4p-1076 : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-intel 0x4p-1076L : 0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh tonearest ldbl-96-intel 0x4p-1076L : 0x4p-1076L : inexact-ok
+= tanh towardzero ldbl-96-intel 0x4p-1076L : 0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh upward ldbl-96-intel 0x4p-1076L : 0x4p-1076L : inexact-ok
+= tanh downward ldbl-96-m68k 0x4p-1076L : 0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh tonearest ldbl-96-m68k 0x4p-1076L : 0x4p-1076L : inexact-ok
+= tanh towardzero ldbl-96-m68k 0x4p-1076L : 0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh upward ldbl-96-m68k 0x4p-1076L : 0x4p-1076L : inexact-ok
+= tanh downward ldbl-128 0x4p-1076L : 0x3.fffffffffffffffffffffffffffep-1076L : inexact-ok
+= tanh tonearest ldbl-128 0x4p-1076L : 0x4p-1076L : inexact-ok
+= tanh towardzero ldbl-128 0x4p-1076L : 0x3.fffffffffffffffffffffffffffep-1076L : inexact-ok
+= tanh upward ldbl-128 0x4p-1076L : 0x4p-1076L : inexact-ok
+= tanh downward ldbl-128ibm 0x4p-1076L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128ibm 0x4p-1076L : 0x4p-1076L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128ibm 0x4p-1076L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128ibm 0x4p-1076L : 0x4p-1076L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-intel 0x8p-16448L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-intel 0x8p-16448L : 0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-intel 0x8p-16448L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-intel 0x8p-16448L : 0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-m68k 0x8p-16448L : 0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-m68k 0x8p-16448L : 0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-m68k 0x8p-16448L : 0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-m68k 0x8p-16448L : 0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-128 0x8p-16448L : 0x7.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 0x8p-16448L : 0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 0x8p-16448L : 0x7.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 0x8p-16448L : 0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-m68k 0x4p-16448L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-m68k 0x4p-16448L : 0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-m68k 0x4p-16448L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-m68k 0x4p-16448L : 0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-128 0x4p-16448L : 0x3.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 0x4p-16448L : 0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 0x4p-16448L : 0x3.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 0x4p-16448L : 0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-128 0x4p-16496L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 0x4p-16496L : 0x4p-16496L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 0x4p-16496L : 0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 0x4p-16496L : 0x4p-16496L : inexact-ok underflow errno-erange-ok
+tanh -min_subnorm
+= tanh downward flt-32 -0x8p-152f : -0x8p-152f : inexact-ok underflow errno-erange-ok
+= tanh tonearest flt-32 -0x8p-152f : -0x8p-152f : inexact-ok underflow errno-erange-ok
+= tanh towardzero flt-32 -0x8p-152f : -0x0p+0f : inexact-ok underflow errno-erange-ok
+= tanh upward flt-32 -0x8p-152f : -0x0p+0f : inexact-ok underflow errno-erange-ok
+= tanh downward dbl-64 -0x8p-152 : -0x8p-152 : inexact-ok
+= tanh tonearest dbl-64 -0x8p-152 : -0x8p-152 : inexact-ok
+= tanh towardzero dbl-64 -0x8p-152 : -0x7.ffffffffffffcp-152 : inexact-ok
+= tanh upward dbl-64 -0x8p-152 : -0x7.ffffffffffffcp-152 : inexact-ok
+= tanh downward ldbl-96-intel -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh tonearest ldbl-96-intel -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh towardzero ldbl-96-intel -0x8p-152L : -0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh upward ldbl-96-intel -0x8p-152L : -0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh downward ldbl-96-m68k -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh tonearest ldbl-96-m68k -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh towardzero ldbl-96-m68k -0x8p-152L : -0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh upward ldbl-96-m68k -0x8p-152L : -0x7.fffffffffffffff8p-152L : inexact-ok
+= tanh downward ldbl-128 -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh tonearest ldbl-128 -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh towardzero ldbl-128 -0x8p-152L : -0x7.fffffffffffffffffffffffffffcp-152L : inexact-ok
+= tanh upward ldbl-128 -0x8p-152L : -0x7.fffffffffffffffffffffffffffcp-152L : inexact-ok
+= tanh downward ldbl-128ibm -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh tonearest ldbl-128ibm -0x8p-152L : -0x8p-152L : inexact-ok
+= tanh towardzero ldbl-128ibm -0x8p-152L : -0x7.fffffffffffffffffffffffffep-152L : inexact-ok
+= tanh upward ldbl-128ibm -0x8p-152L : -0x7.fffffffffffffffffffffffffep-152L : inexact-ok
+= tanh downward dbl-64 -0x4p-1076 : -0x4p-1076 : inexact-ok underflow errno-erange-ok
+= tanh tonearest dbl-64 -0x4p-1076 : -0x4p-1076 : inexact-ok underflow errno-erange-ok
+= tanh towardzero dbl-64 -0x4p-1076 : -0x0p+0 : inexact-ok underflow errno-erange-ok
+= tanh upward dbl-64 -0x4p-1076 : -0x0p+0 : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-intel -0x4p-1076L : -0x4p-1076L : inexact-ok
+= tanh tonearest ldbl-96-intel -0x4p-1076L : -0x4p-1076L : inexact-ok
+= tanh towardzero ldbl-96-intel -0x4p-1076L : -0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh upward ldbl-96-intel -0x4p-1076L : -0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh downward ldbl-96-m68k -0x4p-1076L : -0x4p-1076L : inexact-ok
+= tanh tonearest ldbl-96-m68k -0x4p-1076L : -0x4p-1076L : inexact-ok
+= tanh towardzero ldbl-96-m68k -0x4p-1076L : -0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh upward ldbl-96-m68k -0x4p-1076L : -0x3.fffffffffffffffcp-1076L : inexact-ok
+= tanh downward ldbl-128 -0x4p-1076L : -0x4p-1076L : inexact-ok
+= tanh tonearest ldbl-128 -0x4p-1076L : -0x4p-1076L : inexact-ok
+= tanh towardzero ldbl-128 -0x4p-1076L : -0x3.fffffffffffffffffffffffffffep-1076L : inexact-ok
+= tanh upward ldbl-128 -0x4p-1076L : -0x3.fffffffffffffffffffffffffffep-1076L : inexact-ok
+= tanh downward ldbl-128ibm -0x4p-1076L : -0x4p-1076L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128ibm -0x4p-1076L : -0x4p-1076L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128ibm -0x4p-1076L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128ibm -0x4p-1076L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-intel -0x8p-16448L : -0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-intel -0x8p-16448L : -0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-intel -0x8p-16448L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-intel -0x8p-16448L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-m68k -0x8p-16448L : -0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-m68k -0x8p-16448L : -0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-m68k -0x8p-16448L : -0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-m68k -0x8p-16448L : -0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-128 -0x8p-16448L : -0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 -0x8p-16448L : -0x8p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 -0x8p-16448L : -0x7.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 -0x8p-16448L : -0x7.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-96-m68k -0x4p-16448L : -0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-96-m68k -0x4p-16448L : -0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-96-m68k -0x4p-16448L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-96-m68k -0x4p-16448L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-128 -0x4p-16448L : -0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 -0x4p-16448L : -0x4p-16448L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 -0x4p-16448L : -0x3.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 -0x4p-16448L : -0x3.fffffffffffcp-16448L : inexact-ok underflow errno-erange-ok
+= tanh downward ldbl-128 -0x4p-16496L : -0x4p-16496L : inexact-ok underflow errno-erange-ok
+= tanh tonearest ldbl-128 -0x4p-16496L : -0x4p-16496L : inexact-ok underflow errno-erange-ok
+= tanh towardzero ldbl-128 -0x4p-16496L : -0x0p+0L : inexact-ok underflow errno-erange-ok
+= tanh upward ldbl-128 -0x4p-16496L : -0x0p+0L : inexact-ok underflow errno-erange-ok
 tgamma 0.5
 = tgamma downward flt-32 0x8p-4f : 0x1.c5bf88p+0f : inexact-ok
 = tgamma tonearest flt-32 0x8p-4f : 0x1.c5bf8ap+0f : inexact-ok

diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps
index 36037655f21c59103db38d6b63fe7351cf8453d6..de53451879907395a17e1b6161e75e3efdad9fa7 100644 (file)
--- a/sysdeps/i386/fpu/libm-test-ulps
+++ b/sysdeps/i386/fpu/libm-test-ulps
@@ -1988,12 +1988,16 @@ ldouble: 4
 Function: "tanh_towardzero":
 double: 1
 float: 1
+idouble: 1
+ifloat: 1
 ildouble: 3
 ldouble: 3
 
 Function: "tanh_upward":
 double: 1
 float: 1
+idouble: 1
+ifloat: 1
 ildouble: 5
 ldouble: 4
 

diff --git a/sysdeps/ieee754/dbl-64/s_tanh.c b/sysdeps/ieee754/dbl-64/s_tanh.c
index 23cfcdead5c475278271b9d28661874e475ce707..4f9fcfd2bdf75b730d6d5e86c2b7ee7327fe58b7 100644 (file)
--- a/sysdeps/ieee754/dbl-64/s_tanh.c
+++ b/sysdeps/ieee754/dbl-64/s_tanh.c
@@ -38,6 +38,7 @@ static char rcsid[] = "$NetBSD: s_tanh.c,v 1.7 1995/05/10 20:48:22 jtc Exp $";
  *     only tanh(0)=0 is exact for finite argument.
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -68,7 +69,14 @@ __tanh (double x)
       if ((ix | lx) == 0)
        return x;                       /* x == +-0 */
       if (ix < 0x3c800000)              /* |x|<2**-55 */
-       return x * (one + x);           /* tanh(small) = small */
+       {
+         if (fabs (x) < DBL_MIN)
+           {
+             double force_underflow = x * x;
+             math_force_eval (force_underflow);
+           }
+         return x * (one + x);           /* tanh(small) = small */
+       }
       if (ix >= 0x3ff00000)             /* |x|>=1  */
        {
          t = __expm1 (two * fabs (x));

diff --git a/sysdeps/ieee754/flt-32/s_tanhf.c b/sysdeps/ieee754/flt-32/s_tanhf.c
index dc96da9a5bc673637052b1bbeca506a94df5c4ae..5b48fb2e00bd7fc522d8c4aab6252bcd8a6708d4 100644 (file)
--- a/sysdeps/ieee754/flt-32/s_tanhf.c
+++ b/sysdeps/ieee754/flt-32/s_tanhf.c
@@ -17,6 +17,7 @@
 static char rcsid[] = "$NetBSD: s_tanhf.c,v 1.4 1995/05/10 20:48:24 jtc Exp $";
 #endif
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -41,7 +42,14 @@ float __tanhf(float x)
            if (ix == 0)
                return x;               /* x == +-0 */
            if (ix<0x24000000)          /* |x|<2**-55 */
+             {
+               if (fabsf (x) < FLT_MIN)
+                 {
+                   float force_underflow = x * x;
+                   math_force_eval (force_underflow);
+                 }
                return x*(one+x);       /* tanh(small) = small */
+             }
            if (ix>=0x3f800000) {       /* |x|>=1  */
                t = __expm1f(two*fabsf(x));
                z = one - two/(t+two);

diff --git a/sysdeps/ieee754/ldbl-128/s_tanhl.c b/sysdeps/ieee754/ldbl-128/s_tanhl.c
index 129735b1b59ae4d9fbd3b0223bec8374618b94e9..8b1706fcdca434a3d413f5b6454ec1f3734f6ca1 100644 (file)
--- a/sysdeps/ieee754/ldbl-128/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-128/s_tanhl.c
@@ -41,6 +41,7 @@
  *      only tanhl(0)=0 is exact for finite argument.
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -73,7 +74,14 @@ __tanhl (long double x)
       if (u.value == 0)
        return x;               /* x == +- 0 */
       if (ix < 0x3fc60000)     /* |x| < 2^-57 */
-       return x * (one + tiny); /* tanh(small) = small */
+       {
+         if (fabsl (x) < LDBL_MIN)
+           {
+             long double force_underflow = x * x;
+             math_force_eval (force_underflow);
+           }
+         return x * (one + tiny); /* tanh(small) = small */
+       }
       u.parts32.w0 = ix;       /* Absolute value of x.  */
       if (ix >= 0x3fff0000)
        {                       /* |x| >= 1  */

diff --git a/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c b/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c
index fe396e9bd3ad951c8db75cda276732e2a1f63c77..5342a8b19acee04e999924e555c027d7357ba57c 100644 (file)
--- a/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c
@@ -38,6 +38,7 @@ static char rcsid[] = "$NetBSD: s_tanh.c,v 1.7 1995/05/10 20:48:22 jtc Exp $";
  *     only tanh(0)=0 is exact for finite argument.
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 #include <math_ldbl_opt.h>
@@ -66,7 +67,14 @@ long double __tanhl(long double x)
            if (ix == 0)
                return x;               /* x == +-0 */
            if (ix<0x3c60000000000000LL)        /* |x|<2**-57 */
+             {
+               if (fabsl (x) < LDBL_MIN)
+                 {
+                   long double force_underflow = x * x;
+                   math_force_eval (force_underflow);
+                 }
                return x*(one+x);       /* tanh(small) = small */
+             }
            if (ix>=0x3ff0000000000000LL) {     /* |x|>=1  */
                t = __expm1l(two*fabsl(x));
                z = one - two/(t+two);

diff --git a/sysdeps/ieee754/ldbl-96/s_tanhl.c b/sysdeps/ieee754/ldbl-96/s_tanhl.c
index 7ec6247315e6ad21706e37a25d17d84a46c24786..035037c8c75bca8e4f6889728cf4f860e875c5b4 100644 (file)
--- a/sysdeps/ieee754/ldbl-96/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-96/s_tanhl.c
@@ -42,6 +42,7 @@ static char rcsid[] = "$NetBSD: $";
  *     only tanhl(0)=0 is exact for finite argument.
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -69,7 +70,14 @@ long double __tanhl(long double x)
            if ((ix|j0|j1) == 0)
                return x;               /* x == +- 0 */
            if (ix<0x3fc8)              /* |x|<2**-55 */
+             {
+               if (fabsl (x) < LDBL_MIN)
+                 {
+                   long double force_underflow = x * x;
+                   math_force_eval (force_underflow);
+                 }
                return x*(one+tiny);    /* tanh(small) = small */
+             }
            if (ix>=0x3fff) {   /* |x|>=1  */
                t = __expm1l(two*fabsl(x));
                z = one - two/(t+two);