From 749008ff0361297af02b8574ac8848d35436eac3 Mon Sep 17 00:00:00 2001
From: Joseph Myers <joseph@codesourcery.com>
Date: Tue, 3 Dec 2013 21:49:56 +0000
Subject: Fix exp missing underflows (bug 15268, bug 15425).

---
 sysdeps/i386/fpu/libm-test-ulps   | 32 ++++++++++++++++++++++++
 sysdeps/ieee754/dbl-64/e_exp.c    | 17 ++++++++++---
 sysdeps/x86_64/fpu/libm-test-ulps | 52 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+), 3 deletions(-)

(limited to 'sysdeps')

diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps
index a492da30d6..4ed02a2797 100644
--- a/sysdeps/i386/fpu/libm-test-ulps
+++ b/sysdeps/i386/fpu/libm-test-ulps
@@ -6017,6 +6017,30 @@ ildouble: 1
 ldouble: 1
 
 # exp_towardzero
+Test "exp_towardzero (-0x2.e870a4p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88c1f0cp+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88c1f1p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88c2p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88cp+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a8p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.ebe224p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.ebe228p+8)":
+ildouble: 1
+ldouble: 1
 Test "exp_towardzero (0x2.c5cp+8)":
 double: 1
 idouble: 1
@@ -6047,6 +6071,12 @@ ildouble: 1
 ldouble: 1
 
 # exp_upward
+Test "exp_upward (-0x2.e870a7e5e88c1f0cp+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_upward (-0x2.e870a7e5e88cp+8)":
+ildouble: 1
+ldouble: 1
 Test "exp_upward (1)":
 double: 1
 float: 1
@@ -8112,6 +8142,8 @@ double: 1
 float: 1
 idouble: 1
 ifloat: 1
+ildouble: 1
+ldouble: 1
 
 Function: "expm1":
 ildouble: 1
diff --git a/sysdeps/ieee754/dbl-64/e_exp.c b/sysdeps/ieee754/dbl-64/e_exp.c
index df3aa5efaa..9d35e6d66c 100644
--- a/sysdeps/ieee754/dbl-64/e_exp.c
+++ b/sysdeps/ieee754/dbl-64/e_exp.c
@@ -39,6 +39,7 @@
 #include "uexp.tbl"
 #include <math_private.h>
 #include <fenv.h>
+#include <float.h>
 
 #ifndef SECTION
 # define SECTION
@@ -169,7 +170,7 @@ __ieee754_exp (double x)
 	  else
 	    {
 	      retval = __slowexp (x);
-	      goto ret;
+	      goto check_uflow_ret;
 	    }			/*if error is over bound */
 	}
       ex = -(1022 + ex);
@@ -185,13 +186,23 @@ __ieee754_exp (double x)
 	{
 	  binexp.i[HIGH_HALF] = 0x00100000;
 	  retval = (res - 1.0) * binexp.x;
-	  goto ret;
+	  goto check_uflow_ret;
 	}
       else
 	{
 	  retval = __slowexp (x);
-	  goto ret;
+	  goto check_uflow_ret;
 	}			/*   if error is over bound    */
+    check_uflow_ret:
+      if (retval < DBL_MIN)
+	{
+#if FLT_EVAL_METHOD != 0
+	  volatile
+#endif
+	  double force_underflow = tiny * tiny;
+	  math_force_eval (force_underflow);
+	}
+      goto ret;
     }
   else
     {
diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps
index 5c923e69b3..e78514869d 100644
--- a/sysdeps/x86_64/fpu/libm-test-ulps
+++ b/sysdeps/x86_64/fpu/libm-test-ulps
@@ -6882,6 +6882,30 @@ ildouble: 1
 ldouble: 1
 
 # exp_towardzero
+Test "exp_towardzero (-0x2.e870a4p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88c1f0cp+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88c1f1p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88c2p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a7e5e88cp+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.e870a8p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.ebe224p+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_towardzero (-0x2.ebe228p+8)":
+ildouble: 1
+ldouble: 1
 Test "exp_towardzero (0x2.c5cp+8)":
 ildouble: 1
 ldouble: 1
@@ -6917,6 +6941,32 @@ ildouble: 1
 ldouble: 1
 
 # exp_upward
+Test "exp_upward (-0x2.e870a4p+8)":
+double: 1
+idouble: 1
+Test "exp_upward (-0x2.e870a7e5e88c1f0cp+8)":
+ildouble: 1
+ldouble: 1
+Test "exp_upward (-0x2.e870a7e5e88c2p+8)":
+double: 1
+idouble: 1
+Test "exp_upward (-0x2.e870a7e5e88cp+8)":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+Test "exp_upward (-0x2.e870a8p+8)":
+double: 1
+idouble: 1
+Test "exp_upward (-0x2.ebe224p+8)":
+double: 1
+idouble: 1
+Test "exp_upward (-0x2.ebe227861639p+8)":
+double: 1
+idouble: 1
+Test "exp_upward (-0x2.ebe228p+8)":
+double: 1
+idouble: 1
 Test "exp_upward (-0x4.d2p+8)":
 double: 1
 idouble: 1
@@ -9208,6 +9258,8 @@ double: 1
 float: 1
 idouble: 1
 ifloat: 1
+ildouble: 1
+ldouble: 1
 
 Function: "expm1":
 double: 1
-- 
cgit 1.4.1