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authorGabriel F. T. Gomes <gftg@linux.vnet.ibm.com>2017-01-06 13:05:30 -0200
committerGabriel F. T. Gomes <gftg@linux.vnet.ibm.com>2017-02-12 18:30:38 -0200
commitb987917e6aa7ffe2fd74f0b6a989438e6edd0727 (patch)
treeb8b52e949fb772130ffa853ec1f1e0a2944c87ff /sysdeps/ieee754
parent40b7fbf27310d4f4a899aa2c54740dce5369ec70 (diff)
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ldbl-128: Fix y0 and y1 for -Inf input [BZ #21130]
The Bessel functions of the second type (Yn) are not defined for
negative input and should return NAN with the "invalid" exception
raised, in these cases.  However, current code checks for infinity and
return zero, regardless of the sign.  This error is exposed for long
double when linking with -lieee.  Without this flag, the error is not
exposed, because the wrappers for these functions, which use
__kernel_standard functionality, return the correct value.

Tested for powerpc64le.

	[BZ #21130]
	* sysdeps/ieee754/ldbl-128/e_j0l.c (__ieee754_y0l): Return NAN
	with the "invalid" exception raised when x is -Inf.
	* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_y1l): Likewise.
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/ldbl-128/e_j0l.c7
-rw-r--r--sysdeps/ieee754/ldbl-128/e_j1l.c7
2 files changed, 2 insertions, 12 deletions
diff --git a/sysdeps/ieee754/ldbl-128/e_j0l.c b/sysdeps/ieee754/ldbl-128/e_j0l.c
index d711007136..855b5a578b 100644
--- a/sysdeps/ieee754/ldbl-128/e_j0l.c
+++ b/sysdeps/ieee754/ldbl-128/e_j0l.c
@@ -829,12 +829,7 @@ _Float128
   _Float128 xx, xinv, z, p, q, c, s, cc, ss;
 
   if (! isfinite (x))
-    {
-      if (x != x)
-	return x + x;
-      else
-	return 0;
-    }
+    return 1 / (x + x * x);
   if (x <= 0)
     {
       if (x < 0)
diff --git a/sysdeps/ieee754/ldbl-128/e_j1l.c b/sysdeps/ieee754/ldbl-128/e_j1l.c
index 9e782305d9..db8dca0ab1 100644
--- a/sysdeps/ieee754/ldbl-128/e_j1l.c
+++ b/sysdeps/ieee754/ldbl-128/e_j1l.c
@@ -847,12 +847,7 @@ __ieee754_y1l (_Float128 x)
   _Float128 xx, xinv, z, p, q, c, s, cc, ss;
 
   if (! isfinite (x))
-    {
-      if (x != x)
-	return x + x;
-      else
-	return 0;
-    }
+    return 1 / (x + x * x);
   if (x <= 0)
     {
       if (x < 0)