fix if_nametoindex return value when interface does not exist

[musl] / src / math / atanhl.c

diff --git a/src/math/atanhl.c b/src/math/atanhl.c
index 72a1e34..f63d60b 100644 (file)
--- a/src/math/atanhl.c
+++ b/src/math/atanhl.c
@@ -17,11 +17,18 @@ long double atanhl(long double x)
        u.i.se = e;
        x = u.f;
 
-       if (e < 0x3fff - 1) {
-               /* |x| < 0.5, up to 1.7ulp error */
-               x = 0.5*log1pl(2*x + 2*x*x/(1-x));
+       if (e < 0x3ff - 1) {
+               if (e < 0x3ff - LDBL_MANT_DIG/2) {
+                       /* handle underflow */
+                       if (e == 0)
+                               FORCE_EVAL((float)x);
+               } else {
+                       /* |x| < 0.5, up to 1.7ulp error */
+                       x = 0.5*log1pl(2*x + 2*x*x/(1-x));
+               }
        } else {
-               x = 0.5*log1pl(2*x/(1-x));
+               /* avoid overflow */
+               x = 0.5*log1pl(2*(x/(1-x)));
        }
        return s ? -x : x;
 }