Make nextafter, nexttoward set errno (bug 6799).

nextafter and nexttoward fail to set errno on overflow and underflow.
This patch makes them do so in cases that should include all the cases
where such errno setting is required by glibc's goals for when to set
errno (but not all cases of underflow where the result is nonzero and
so glibc's goals do not require errno setting).

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #6799]
	* math/s_nextafter.c: Include <errno.h>.
	(__nextafter): Set errno on overflow and underflow.
	* math/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/i386/fpu/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* sysdeps/i386/fpu/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/i386/fpu/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/flt-32/s_nextafterf.c: Include <errno.h>.
	(__nextafterf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-96/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include <errno.h>.
	(__nldbl_nexttowardf): Set errno on overflow and underflow.
	* sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* math/libm-test.inc (nextafter_test_data): Do not allow errno
	setting to be missing on overflow.  Add more tests.
	(nexttoward_test_data): Likewise.

19 files changed, 102 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index fdd9da4..d9c0689 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,42 @@
 2015-11-02  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #6799]
+	* math/s_nextafter.c: Include <errno.h>.
+	(__nextafter): Set errno on overflow and underflow.
+	* math/s_nexttowardf.c: Include <errno.h>.
+	(__nexttowardf): Set errno on overflow and underflow.
+	* sysdeps/i386/fpu/s_nextafterl.c: Include <errno.h>.
+	(__nextafterl): Set errno on overflow and underflow.
+	* sysdeps/i386/fpu/s_nexttoward.c: Include <errno.h>.
+	(__nexttoward): Set errno on overflow and underflow.
+	* sysdeps/i386/fpu/s_nexttowardf.c: Include <errno.h>.
+	(__nexttowardf): Set errno on overflow and underflow.
+	* sysdeps/ieee754/flt-32/s_nextafterf.c: Include <errno.h>.
+	(__nextafterf): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-128/s_nextafterl.c: Include <errno.h>.
+	(__nextafterl): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-128/s_nexttoward.c: Include <errno.h>.
+	(__nexttoward): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Include <errno.h>.
+	(__nexttowardf): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <errno.h>.
+	(__nextafterl): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Include <errno.h>.
+	(__nexttoward): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include <errno.h>.
+	(__nexttowardf): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-96/s_nexttoward.c: Include <errno.h>.
+	(__nexttoward): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include <errno.h>.
+	(__nexttowardf): Set errno on overflow and underflow.
+	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include <errno.h>.
+	(__nldbl_nexttowardf): Set errno on overflow and underflow.
+	* sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Include <errno.h>.
+	(__nextafterl): Set errno on overflow and underflow.
+	* math/libm-test.inc (nextafter_test_data): Do not allow errno
+	setting to be missing on overflow.  Add more tests.
+	(nexttoward_test_data): Likewise.
+
 	* configure.ac (libc_cv_initfini_array): Remove configure test.
 	* configure: Regenerated.
 
diff --git a/NEWS b/NEWS
index 654217c..1cc08a0 100644
--- a/NEWS
+++ b/NEWS
@@ -9,7 +9,7 @@ Version 2.23
 
 * The following bugs are resolved with this release:
 
-  887, 2542, 2543, 2558, 2898, 4404, 6803, 10432, 14341, 14912, 15367,
+  887, 2542, 2543, 2558, 2898, 4404, 6799, 6803, 10432, 14341, 14912, 15367,
   15384, 15470, 15491, 15786, 15918, 16068, 16141, 16171, 16296, 16347,
   16399, 16415, 16422, 16517, 16519, 16520, 16521, 16620, 16734, 16973,
   16985, 17118, 17243, 17244, 17250, 17404, 17441, 17787, 17886, 17887,
diff --git a/math/libm-test.inc b/math/libm-test.inc
index ace51c9..1267b81 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -9850,9 +9850,13 @@ static const struct test_ff_f_data nextafter_test_data[] =
     TEST_ff_f (nextafter, 1.1L, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (nextafter, qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
 
-    /* Bug 6799: errno setting may be missing.  */
-    TEST_ff_f (nextafter, max_value, plus_infty, plus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION),
-    TEST_ff_f (nextafter, -max_value, minus_infty, minus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION),
+    TEST_ff_f (nextafter, max_value, plus_infty, plus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nextafter, -max_value, minus_infty, minus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION|ERRNO_ERANGE),
+
+    TEST_ff_f (nextafter, min_subnorm_value, 0, 0, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nextafter, min_subnorm_value, minus_zero, 0, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nextafter, -min_subnorm_value, 0, minus_zero, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nextafter, -min_subnorm_value, minus_zero, minus_zero, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
 
 #ifdef TEST_LDOUBLE
     // XXX Enable once gcc is fixed.
@@ -9894,9 +9898,13 @@ static const struct test_ff_f_data_nexttoward nexttoward_test_data[] =
     TEST_ff_f (nexttoward, 1.1L, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (nexttoward, qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
 
-    /* Bug 6799: errno setting may be missing.  */
-    TEST_ff_f (nexttoward, max_value, plus_infty, plus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION),
-    TEST_ff_f (nexttoward, -max_value, minus_infty, minus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION),
+    TEST_ff_f (nexttoward, max_value, plus_infty, plus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nexttoward, -max_value, minus_infty, minus_infty, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION|ERRNO_ERANGE),
+
+    TEST_ff_f (nexttoward, min_subnorm_value, 0, 0, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nexttoward, min_subnorm_value, minus_zero, 0, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nexttoward, -min_subnorm_value, 0, minus_zero, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
+    TEST_ff_f (nexttoward, -min_subnorm_value, minus_zero, minus_zero, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_ERANGE),
 
 #ifdef TEST_FLOAT
     TEST_ff_f (nexttoward, 1.0, 1.1L, 0x1.000002p0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
diff --git a/math/s_nextafter.c b/math/s_nextafter.c
index 28962e5..dfa5e86 100644
--- a/math/s_nextafter.c
+++ b/math/s_nextafter.c
@@ -25,6 +25,7 @@ static char rcsid[] = "$NetBSD: s_nextafter.c,v 1.8 1995/05/10 20:47:58 jtc Exp
 #define __nexttoward __internal___nexttoward
 #define nexttoward __internal_nexttoward
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -72,10 +73,12 @@ double __nextafter(double x, double y)
 	if(hy>=0x7ff00000) {
 	  double u = x+x;	/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00100000) {
 	    double u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	  __set_errno (ERANGE);
 	}
 	INSERT_WORDS(x,hx,lx);
 	return x;
diff --git a/math/s_nexttowardf.c b/math/s_nexttowardf.c
index 06350d4..30cd81b 100644
--- a/math/s_nexttowardf.c
+++ b/math/s_nexttowardf.c
@@ -20,6 +20,7 @@
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -61,10 +62,12 @@ float __nexttowardf(float x, long double y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {
 	    float u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/i386/fpu/s_nextafterl.c b/sysdeps/i386/fpu/s_nextafterl.c
index 66d903f..188dc21 100644
--- a/sysdeps/i386/fpu/s_nextafterl.c
+++ b/sysdeps/i386/fpu/s_nextafterl.c
@@ -26,6 +26,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -109,10 +110,12 @@ long double __nextafterl(long double x, long double y)
 	if(esy==0x7fff) {
 	    long double u = x + x;	/* overflow  */
 	    math_force_eval (u);
+	    __set_errno (ERANGE);
 	}
 	if(esy==0) {
 	    long double u = x*x;		/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_LDOUBLE_WORDS(x,esx,hx,lx);
 	return x;
diff --git a/sysdeps/i386/fpu/s_nexttoward.c b/sysdeps/i386/fpu/s_nexttoward.c
index 839efe6..0b47044 100644
--- a/sysdeps/i386/fpu/s_nexttoward.c
+++ b/sysdeps/i386/fpu/s_nexttoward.c
@@ -26,6 +26,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -75,10 +76,12 @@ double __nexttoward(double x, long double y)
 	if(hy>=0x7ff00000) {
 	  double u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00100000) {
 	    double u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	INSERT_WORDS(x,hx,lx);
 	return x;
diff --git a/sysdeps/i386/fpu/s_nexttowardf.c b/sysdeps/i386/fpu/s_nexttowardf.c
index 29b4f12..e1156d1 100644
--- a/sysdeps/i386/fpu/s_nexttowardf.c
+++ b/sysdeps/i386/fpu/s_nexttowardf.c
@@ -18,6 +18,7 @@
 static char rcsid[] = "$NetBSD: $";
 #endif
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -63,10 +64,12 @@ float __nexttowardf(float x, long double y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {
 	    float u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/ieee754/flt-32/s_nextafterf.c b/sysdeps/ieee754/flt-32/s_nextafterf.c
index 22e0b3d..625d54b 100644
--- a/sysdeps/ieee754/flt-32/s_nextafterf.c
+++ b/sysdeps/ieee754/flt-32/s_nextafterf.c
@@ -17,6 +17,7 @@
 static char rcsid[] = "$NetBSD: s_nextafterf.c,v 1.4 1995/05/10 20:48:01 jtc Exp $";
 #endif
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -59,10 +60,12 @@ float __nextafterf(float x, float y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;	/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {
 	    float u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128/s_nextafterl.c b/sysdeps/ieee754/ldbl-128/s_nextafterl.c
index d5eaa1c..4e9a2ce 100644
--- a/sysdeps/ieee754/ldbl-128/s_nextafterl.c
+++ b/sysdeps/ieee754/ldbl-128/s_nextafterl.c
@@ -24,6 +24,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -70,10 +71,12 @@ long double __nextafterl(long double x, long double y)
 	if(hy==0x7fff000000000000LL) {
 	    long double u = x + x;		/* overflow  */
 	    math_force_eval (u);
+	    __set_errno (ERANGE);
 	}
 	if(hy==0) {
 	    long double u = x*x;		/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_LDOUBLE_WORDS64(x,hx,lx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128/s_nexttoward.c b/sysdeps/ieee754/ldbl-128/s_nexttoward.c
index 2ee7a1b..4343fe8 100644
--- a/sysdeps/ieee754/ldbl-128/s_nexttoward.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttoward.c
@@ -25,6 +25,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -75,10 +76,12 @@ double __nexttoward(double x, long double y)
 	if(hy>=0x7ff00000) {
 	  double u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00100000) {
 	    double u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	INSERT_WORDS(x,hx,lx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
index 9c9c7e5..8703359 100644
--- a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
@@ -18,6 +18,7 @@
 static char rcsid[] = "$NetBSD: $";
 #endif
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -62,10 +63,12 @@ float __nexttowardf(float x, long double y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;		/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {
 	    float u = x*x;		/* underflow */
 	    math_force_eval (u);	/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
index 36a5090..515aa1e 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c
@@ -24,6 +24,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <float.h>
 #include <math.h>
 #include <math_private.h>
@@ -69,6 +70,7 @@ long double __nextafterl(long double x, long double y)
 	    if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL)) {
 	      u = x+x;	/* overflow, return -inf */
 	      math_force_eval (u);
+	      __set_errno (ERANGE);
 	      return y;
 	    }
 	    if (hx >= 0x7ff0000000000000LL) {
@@ -83,6 +85,7 @@ long double __nextafterl(long double x, long double y)
 		  || (hx < 0 && lx > 1)) {
 		u = u * u;
 		math_force_eval (u);		/* raise underflow flag */
+		__set_errno (ERANGE);
 	      }
 	      return x;
 	    }
@@ -108,6 +111,7 @@ long double __nextafterl(long double x, long double y)
 	    if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL)) {
 	      u = x+x;	/* overflow, return +inf */
 	      math_force_eval (u);
+	      __set_errno (ERANGE);
 	      return y;
 	    }
 	    if ((uint64_t) hx >= 0xfff0000000000000ULL) {
@@ -122,6 +126,7 @@ long double __nextafterl(long double x, long double y)
 		  || (hx < 0 && lx >= 0)) {
 		u = u * u;
 		math_force_eval (u);		/* raise underflow flag */
+		__set_errno (ERANGE);
 	      }
 	      if (x == 0.0L)	/* handle negative LDBL_TRUE_MIN case */
 		x = -0.0L;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c b/sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c
index 8c61198..d8f4fc6 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c
@@ -25,6 +25,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <math_ldbl_opt.h>
@@ -76,10 +77,12 @@ double __nexttoward(double x, long double y)
 	if(hy>=0x7ff00000) {
 	  double u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00100000) {
 	    double u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	INSERT_WORDS(x,hx,lx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c b/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c
index 4000a93..7c5d1cc 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c
@@ -18,6 +18,7 @@
 static char rcsid[] = "$NetBSD: $";
 #endif
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <math_ldbl_opt.h>
@@ -65,10 +66,12 @@ float __nexttowardf(float x, long double y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;		/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {		/* underflow */
 	    float u = x*x;
 	    math_force_eval (u);	/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-96/s_nexttoward.c b/sysdeps/ieee754/ldbl-96/s_nexttoward.c
index 7908f9c..3d0382e 100644
--- a/sysdeps/ieee754/ldbl-96/s_nexttoward.c
+++ b/sysdeps/ieee754/ldbl-96/s_nexttoward.c
@@ -25,6 +25,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -72,10 +73,12 @@ double __nexttoward(double x, long double y)
 	if(hy>=0x7ff00000) {
 	  double u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00100000) {
 	    double u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	INSERT_WORDS(x,hx,lx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-96/s_nexttowardf.c b/sysdeps/ieee754/ldbl-96/s_nexttowardf.c
index 53c527d..ae75389 100644
--- a/sysdeps/ieee754/ldbl-96/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-96/s_nexttowardf.c
@@ -17,6 +17,7 @@
 static char rcsid[] = "$NetBSD: $";
 #endif
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <float.h>
@@ -60,10 +61,12 @@ float __nexttowardf(float x, long double y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {
 	    float u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c b/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c
index dbcf840..07e9375 100644
--- a/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c
+++ b/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c
@@ -20,6 +20,7 @@
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <math_ldbl_opt.h>
@@ -64,10 +65,12 @@ float __nldbl_nexttowardf(float x, double y)
 	if(hy>=0x7f800000) {
 	  float u = x+x;			/* overflow  */
 	  math_force_eval (u);
+	  __set_errno (ERANGE);
 	}
 	if(hy<0x00800000) {
 	    float u = x*x;			/* underflow */
 	    math_force_eval (u);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_FLOAT_WORD(x,hx);
 	return x;
diff --git a/sysdeps/m68k/m680x0/fpu/s_nextafterl.c b/sysdeps/m68k/m680x0/fpu/s_nextafterl.c
index ad77ca4..c46c0e7 100644
--- a/sysdeps/m68k/m680x0/fpu/s_nextafterl.c
+++ b/sysdeps/m68k/m680x0/fpu/s_nextafterl.c
@@ -26,6 +26,7 @@ static char rcsid[] = "$NetBSD: $";
  *   Special cases:
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -92,10 +93,12 @@ long double __nextafterl(long double x, long double y)
 	if(esy==0x7fff) {
 	    long double u = x + x;	/* overflow  */
 	    math_force_eval (u);
+	    __set_errno (ERANGE);
 	}
 	if(esy==0 && (hx & 0x80000000) == 0) { /* underflow */
 	    y = x*x;
 	    math_force_eval (y);		/* raise underflow flag */
+	    __set_errno (ERANGE);
 	}
 	SET_LDOUBLE_WORDS(x,esx,hx,lx);
 	return x;