6 files changed, 10 insertions, 8 deletions
diff --git a/src/math/__expo2.c b/src/math/__expo2.c
index 740ac680..248f052b 100644
--- a/src/math/__expo2.c
+++ b/src/math/__expo2.c
@@ -5,12 +5,13 @@ static const int k = 2043;
 static const double kln2 = 0x1.62066151add8bp+10;
 
 /* exp(x)/2 for x >= log(DBL_MAX), slightly better than 0.5*exp(x/2)*exp(x/2) */
-double __expo2(double x)
+double __expo2(double x, double sign)
 {
 	double scale;
 
 	/* note that k is odd and scale*scale overflows */
 	INSERT_WORDS(scale, (uint32_t)(0x3ff + k/2) << 20, 0);
 	/* exp(x - k ln2) * 2**(k-1) */
-	return exp(x - kln2) * scale * scale;
+	/* in directed rounding correct sign before rounding or overflow is important */
+	return exp(x - kln2) * (sign * scale) * scale;
 }
diff --git a/src/math/__expo2f.c b/src/math/__expo2f.c
index 5163e418..538eb09c 100644
--- a/src/math/__expo2f.c
+++ b/src/math/__expo2f.c
@@ -5,12 +5,13 @@ static const int k = 235;
 static const float kln2 = 0x1.45c778p+7f;
 
 /* expf(x)/2 for x >= log(FLT_MAX), slightly better than 0.5f*expf(x/2)*expf(x/2) */
-float __expo2f(float x)
+float __expo2f(float x, float sign)
 {
 	float scale;
 
 	/* note that k is odd and scale*scale overflows */
 	SET_FLOAT_WORD(scale, (uint32_t)(0x7f + k/2) << 23);
 	/* exp(x - k ln2) * 2**(k-1) */
-	return expf(x - kln2) * scale * scale;
+	/* in directed rounding correct sign before rounding or overflow is important */
+	return expf(x - kln2) * (sign * scale) * scale;
 }
diff --git a/src/math/cosh.c b/src/math/cosh.c
index 100f8231..490c15fb 100644
--- a/src/math/cosh.c
+++ b/src/math/cosh.c
@@ -35,6 +35,6 @@ double cosh(double x)
 
 	/* |x| > log(DBL_MAX) or nan */
 	/* note: the result is stored to handle overflow */
-	t = __expo2(x);
+	t = __expo2(x, 1.0);
 	return t;
 }
diff --git a/src/math/coshf.c b/src/math/coshf.c
index b09f2ee5..e739cff9 100644
--- a/src/math/coshf.c
+++ b/src/math/coshf.c
@@ -28,6 +28,6 @@ float coshf(float x)
 	}
 
 	/* |x| > log(FLT_MAX) or nan */
-	t = __expo2f(x);
+	t = __expo2f(x, 1.0f);
 	return t;
 }
diff --git a/src/math/sinh.c b/src/math/sinh.c
index 00022c4e..a01951ae 100644
--- a/src/math/sinh.c
+++ b/src/math/sinh.c
@@ -34,6 +34,6 @@ double sinh(double x)
 
 	/* |x| > log(DBL_MAX) or nan */
 	/* note: the result is stored to handle overflow */
-	t = 2*h*__expo2(absx);
+	t = __expo2(absx, 2*h);
 	return t;
 }
diff --git a/src/math/sinhf.c b/src/math/sinhf.c
index 6ad19ea2..b9caa793 100644
--- a/src/math/sinhf.c
+++ b/src/math/sinhf.c
@@ -26,6 +26,6 @@ float sinhf(float x)
 	}
 
 	/* |x| > logf(FLT_MAX) or nan */
-	t = 2*h*__expo2f(absx);
+	t = __expo2f(absx, 2*h);
 	return t;
 }