X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Fatanhl.c;h=f63d60b153faec6881f5ecc7007e5d2a418adbe1;hb=8041af59881219c32267c3491bee43591d3c3fe6;hp=72a1e345b88e383824267aefb0e7280e915debc9;hpb=aa0c4a204e28cfc90a9ee955691a6cbe014c9fde;p=musl

diff --git a/src/math/atanhl.c b/src/math/atanhl.c
index 72a1e345..f63d60b1 100644
--- 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;
 }