2 files changed, 4 insertions, 1 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_frexp.c b/sysdeps/ieee754/dbl-64/s_frexp.c
index 1b8d8500ba..874214ec7c 100644
--- a/sysdeps/ieee754/dbl-64/s_frexp.c
+++ b/sysdeps/ieee754/dbl-64/s_frexp.c
@@ -38,7 +38,7 @@ __frexp (double x, int *eptr)
   ix = 0x7fffffff & hx;
   *eptr = 0;
   if (ix >= 0x7ff00000 || ((ix | lx) == 0))
-    return x;                                           /* 0,inf,nan */
+    return x + x;                                           /* 0,inf,nan */
   if (ix < 0x00100000)                  /* subnormal */
     {
       x *= two54;
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c
index 42068f8187..4b075b7200 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c
@@ -55,6 +55,9 @@ __frexp (double x, int *eptr)
       ix = (ix & INT64_C (0x800fffffffffffff)) | INT64_C (0x3fe0000000000000);
       INSERT_WORDS64 (x, ix);
     }
+  else
+    /* Quiet signaling NaNs.  */
+    x += x;
 
   *eptr = e;
   return x;