Sync with upstream FreeBSD libm.
Change-Id: I97e9b23903f1d993d84825806065e85626007d31
diff --git a/libm/upstream-freebsd/lib/msun/src/e_jn.c b/libm/upstream-freebsd/lib/msun/src/e_jn.c
index 8b0bc62..a1130c5 100644
--- a/libm/upstream-freebsd/lib/msun/src/e_jn.c
+++ b/libm/upstream-freebsd/lib/msun/src/e_jn.c
@@ -12,7 +12,7 @@
*/
#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+__FBSDID("$FreeBSD: head/lib/msun/src/e_jn.c 279856 2015-03-10 17:10:54Z kargl $");
/*
* __ieee754_jn(n, x), __ieee754_yn(n, x)
@@ -43,6 +43,8 @@
#include "math.h"
#include "math_private.h"
+static const volatile double vone = 1, vzero = 0;
+
static const double
invsqrtpi= 5.64189583547756279280e-01, /* 0x3FE20DD7, 0x50429B6D */
two = 2.00000000000000000000e+00, /* 0x40000000, 0x00000000 */
@@ -220,10 +222,12 @@
EXTRACT_WORDS(hx,lx,x);
ix = 0x7fffffff&hx;
- /* if Y(n,NaN) is NaN */
+ /* yn(n,NaN) = NaN */
if((ix|((u_int32_t)(lx|-lx))>>31)>0x7ff00000) return x+x;
- if((ix|lx)==0) return -one/zero;
- if(hx<0) return zero/zero;
+ /* yn(n,+-0) = -inf and raise divide-by-zero exception. */
+ if((ix|lx)==0) return -one/vzero;
+ /* yn(n,x<0) = NaN and raise invalid exception. */
+ if(hx<0) return vzero/vzero;
sign = 1;
if(n<0){
n = -n;