Added more checks to test the correctness of the pexp implementation

1 files changed, 22 insertions, 2 deletions

diff --git a/test/packetmath.cpp b/test/packetmath.cpp
index 2f1accd1b..53fc09a2d 100644
--- a/test/packetmath.cpp
+++ b/test/packetmath.cpp
@@ -315,9 +315,29 @@ template<typename Scalar> void packetmath_real()
   CHECK_CWISE1_IF(internal::packet_traits<Scalar>::HasExp, std::exp, internal::pexp);
   {
     data1[0] = std::numeric_limits<Scalar>::quiet_NaN();
+    data1[1] = std::numeric_limits<Scalar>::epsilon();
     packet_helper<internal::packet_traits<Scalar>::HasExp,Packet> h;
-    h.store(data2, internal::pexp(h.load(data1))); 
-    VERIFY(numext::isnan(data2[0]));
+    h.store(data2, internal::pexp(h.load(data1)));
+    VERIFY(std::isnan(data2[0]));
+    VERIFY_IS_EQUAL(std::exp(std::numeric_limits<Scalar>::epsilon()), data2[1]);
+
+    data1[0] = -std::numeric_limits<Scalar>::epsilon();
+    data1[1] = 0;
+    h.store(data2, internal::pexp(h.load(data1)));
+    VERIFY_IS_EQUAL(std::exp(-std::numeric_limits<Scalar>::epsilon()), data2[0]);
+    VERIFY_IS_EQUAL(std::exp(0), data2[1]);
+
+    data1[0] = (std::numeric_limits<Scalar>::min)();
+    data1[1] = -(std::numeric_limits<Scalar>::min)();
+    h.store(data2, internal::pexp(h.load(data1)));
+    VERIFY_IS_EQUAL(std::exp((std::numeric_limits<Scalar>::min)()), data2[0]);
+    VERIFY_IS_EQUAL(std::exp(-(std::numeric_limits<Scalar>::min)()), data2[1]);
+
+    data1[0] = std::numeric_limits<Scalar>::denorm_min();
+    data1[1] = -std::numeric_limits<Scalar>::denorm_min();
+    h.store(data2, internal::pexp(h.load(data1)));
+    VERIFY_IS_EQUAL(std::exp(std::numeric_limits<Scalar>::denorm_min()), data2[0]);
+    VERIFY_IS_EQUAL(std::exp(-std::numeric_limits<Scalar>::denorm_min()), data2[1]);
   }
 
   for (int i=0; i<size; ++i)