1 files changed, 11 insertions, 2 deletions
diff --git a/libc/sysdeps/ieee754/ldbl-128ibm/s_erfl.c b/libc/sysdeps/ieee754/ldbl-128ibm/s_erfl.c
index c861c65cc..95dc41584 100644
--- a/libc/sysdeps/ieee754/ldbl-128ibm/s_erfl.c
+++ b/libc/sysdeps/ieee754/ldbl-128ibm/s_erfl.c
@@ -101,6 +101,7 @@
  *		erfc/erf(NaN) is NaN
  */
 
+#include <errno.h>
 #include <math.h>
 #include <math_private.h>
 #include <math_ldbl_opt.h>
@@ -940,14 +941,22 @@ __erfcl (long double x)
       r = __ieee754_expl (-z * z - 0.5625) *
 	__ieee754_expl ((z - x) * (z + x) + p);
       if ((hx & 0x80000000) == 0)
-	return r / x;
+	{
+	  long double ret = r / x;
+	  if (ret == 0)
+	    __set_errno (ERANGE);
+	  return ret;
+	}
       else
 	return two - r / x;
     }
   else
     {
       if ((hx & 0x80000000) == 0)
-	return tiny * tiny;
+	{
+	  __set_errno (ERANGE);
+	  return tiny * tiny;
+	}
       else
 	return two - tiny;
     }