X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Ftanl.c;h=60e6637613f2837ca9770ad9571fe342a0ebd92f;hb=1a2869593e115e4a6c74aaa0b23ca612357403ce;hp=d173d6bd54fdff972e0abf83266a6d8b47dd9056;hpb=78d9eefec40598cc9661d5a66318f79c832a5216;p=gnulib.git

diff --git a/lib/tanl.c b/lib/tanl.c
index d173d6bd5..60e663761 100644
--- a/lib/tanl.c
+++ b/lib/tanl.c
@@ -124,7 +124,7 @@ long double
 kernel_tanl (long double x, long double y, int iy)
 {
   long double z, r, v, w, s, u, u1;
-  int flag, sign;
+  int invert = 0, sign;
 
   sign = 1;
   if (x < 0)
@@ -146,7 +146,7 @@ kernel_tanl (long double x, long double y, int iy)
     }
   if (x >= 0.6743316650390625) /* |x| >= 0.6743316650390625 */
     {
-      flag = 1;
+      invert = 1;
 
       z = pio4hi - x;
       w = pio4lo - y;
@@ -162,7 +162,7 @@ kernel_tanl (long double x, long double y, int iy)
   r = y + z * (s * r + y);
   r += TH * s;
   w = x + r;
-  if (flag)
+  if (invert)
     {
       v = (long double) iy;
       w = (v - 2.0 * (x - (w * w / (w + v) - r)));
@@ -191,13 +191,17 @@ tanl (long double x)
   long double y[2], z = 0.0L;
   int n;
 
+  /* tanl(NaN) is NaN */
+  if (isnanl (x))
+    return x;
+
   /* |x| ~< pi/4 */
   if (x >= -0.7853981633974483096156608458198757210492 &&
       x <= 0.7853981633974483096156608458198757210492)
     return kernel_tanl (x, z, 1);
 
-  /* tanl(Inf or NaN) is NaN, tanl(0) is 0 */
-  else if (x + x == x || x != x)
+  /* tanl(Inf) is NaN, tanl(0) is 0 */
+  else if (x + x == x)
     return x - x;		/* NaN */
 
   /* argument reduction needed */