x86 long double: Consider pseudo numbers as signaling

Add support to treat pseudo-numbers specially and implement x86
version to consider all of them as signaling.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/sysdeps/ieee754/ldbl-96/s_issignalingl.c b/sysdeps/ieee754/ldbl-96/s_issignalingl.c
index ec542ad..37e05aa 100644
--- a/sysdeps/ieee754/ldbl-96/s_issignalingl.c
+++ b/sysdeps/ieee754/ldbl-96/s_issignalingl.c
@@ -19,12 +19,19 @@
 #include <math.h>
 #include <math_private.h>
 #include <nan-high-order-bit.h>
+#include <nan-pseudo-number.h>
 
 int
 __issignalingl (long double x)
 {
   uint32_t exi, hxi, lxi;
   GET_LDOUBLE_WORDS (exi, hxi, lxi, x);
+
+  /* By default we do not recognize a pseudo NaN as sNaN.  However on 80387 and
+     later all pseudo numbers including pseudo NaNs result in a signal and are
+     hence recognized as signaling.  */
+  int ret = is_pseudo_signaling (exi, hxi);
+
 #if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
 # error not implemented
 #else
@@ -34,11 +41,9 @@ __issignalingl (long double x)
   hxi ^= 0x40000000;
   /* If lxi != 0, then set any suitable bit of the significand in hxi.  */
   hxi |= (lxi | -lxi) >> 31;
-  /* We do not recognize a pseudo NaN as sNaN; they're invalid on 80387 and
-     later.  */
   /* We have to compare for greater (instead of greater or equal), because x's
      significand being all-zero designates infinity not NaN.  */
-  return ((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000);
+  return ret || (((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000));
 #endif
 }
 libm_hidden_def (__issignalingl)