From f9140213981b982b635f617cbd529e3b9090405a Mon Sep 17 00:00:00 2001
From: wkcn <wkcn@live.cn>
Date: Fri, 20 Sep 2019 20:22:01 +0800
Subject: [PATCH 1/3] fix min max infinity value

---
 3rdparty/mshadow/mshadow/base.h        | 43 ++++++++++++++++++++++++--
 tests/python/unittest/test_operator.py | 16 ++++++++++
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/3rdparty/mshadow/mshadow/base.h b/3rdparty/mshadow/mshadow/base.h
index d08efd387c7e..3ce102c61ff5 100755
--- a/3rdparty/mshadow/mshadow/base.h
+++ b/3rdparty/mshadow/mshadow/base.h
@@ -645,6 +645,25 @@ MSHADOW_XINLINE int64_t MinValue<int64_t>(void) {
   return LLONG_MIN;
 }
 
+/*!
+ * \brief negative infinity of certain types
+ * \tparam DType data type
+ */
+template<typename DType>
+MSHADOW_XINLINE DType NegInfValue(void) {
+  return MinValue<DType>();
+}
+/*! \brief negative infinity value of float */
+template<>
+MSHADOW_XINLINE float NegInfValue<float>(void) {
+  return -std::numeric_limits<float>::infinity();
+}
+/*! \brief negative infinity value of double */
+template<>
+MSHADOW_XINLINE double NegInfValue<double>(void) {
+  return -std::numeric_limits<double>::infinity();
+}
+
 /*!
  * \brief maximum value of certain types
  * \tparam DType data type
@@ -686,6 +705,26 @@ template<>
 MSHADOW_XINLINE int64_t MaxValue<int64_t>(void) {
   return LLONG_MAX;
 }
+
+/*!
+ * \brief positive infinity of certain types
+ * \tparam DType data type
+ */
+template<typename DType>
+MSHADOW_XINLINE DType PosInfValue(void) {
+  return MaxValue<DType>();
+}
+/*! \brief positive infinity value of float */
+template<>
+MSHADOW_XINLINE float PosInfValue<float>(void) {
+  return std::numeric_limits<float>::infinity();
+}
+/*! \brief positive infinity value of double */
+template<>
+MSHADOW_XINLINE double PosInfValue<double>(void) {
+  return std::numeric_limits<double>::infinity();
+}
+
 }  // namespace limits
 
 /*! \brief sum reducer */
@@ -793,7 +832,7 @@ struct maximum {
    */
   template<typename DType>
   MSHADOW_XINLINE static void SetInitValue(DType &initv) { // NOLINT(*)
-    initv = limits::MinValue<DType>();
+    initv = limits::NegInfValue<DType>();
   }
   /*!
    *\brief set the initial value during reduction
@@ -849,7 +888,7 @@ struct minimum {
    */
   template<typename DType>
   MSHADOW_XINLINE static void SetInitValue(DType &initv) { // NOLINT(*)
-    initv = limits::MaxValue<DType>();
+    initv = limits::PosInfValue<DType>();
   }
   /*!
    *\brief set the initial value during reduction
diff --git a/tests/python/unittest/test_operator.py b/tests/python/unittest/test_operator.py
index 2e7cc3ce7504..51725dbde8c2 100644
--- a/tests/python/unittest/test_operator.py
+++ b/tests/python/unittest/test_operator.py
@@ -9252,6 +9252,22 @@ def test_sample_normal_default_shape():
     assert s.shape == (1, 1)
 
 
+def test_min_max_inf():
+    dtypes = [np.float32, np.double]
+    elem_list = [-1, 1, 0, np.inf, -np.inf]
+
+    for dtype in dtypes:
+        for a in elem_list:
+            for b in elem_list:
+                data_np = np.array([a, b], dtype=dtype)
+                data_mx = mx.nd.array(data_np, dtype=dtype)
+
+                min_data_np, max_data_np = data_np.min(), data_np.max()
+                min_data_mx, max_data_mx = data_mx.min(), data_mx.max()
+
+                assert_array_equal(min_data_np, min_data_mx.asnumpy())
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule()

From 752d400139471df49418976cd6a06d173aa2f782 Mon Sep 17 00:00:00 2001
From: wkcn <wkcn@live.cn>
Date: Fri, 20 Sep 2019 20:30:35 +0800
Subject: [PATCH 2/3] add test maximum

---
 tests/python/unittest/test_operator.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/python/unittest/test_operator.py b/tests/python/unittest/test_operator.py
index 51725dbde8c2..068aab939104 100644
--- a/tests/python/unittest/test_operator.py
+++ b/tests/python/unittest/test_operator.py
@@ -9266,6 +9266,7 @@ def test_min_max_inf():
                 min_data_mx, max_data_mx = data_mx.min(), data_mx.max()
 
                 assert_array_equal(min_data_np, min_data_mx.asnumpy())
+                assert_array_equal(max_data_np, max_data_mx.asnumpy())
 
 
 if __name__ == '__main__':

From 521adf2270d7d876cc4e7a2f45f7b78c345d17e3 Mon Sep 17 00:00:00 2001
From: wkcn <wkcn@live.cn>
Date: Fri, 20 Sep 2019 20:52:16 +0800
Subject: [PATCH 3/3] use HUGE_VAL macro for nvcc

---
 3rdparty/mshadow/mshadow/base.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/3rdparty/mshadow/mshadow/base.h b/3rdparty/mshadow/mshadow/base.h
index 3ce102c61ff5..1076f122c3ae 100755
--- a/3rdparty/mshadow/mshadow/base.h
+++ b/3rdparty/mshadow/mshadow/base.h
@@ -656,12 +656,12 @@ MSHADOW_XINLINE DType NegInfValue(void) {
 /*! \brief negative infinity value of float */
 template<>
 MSHADOW_XINLINE float NegInfValue<float>(void) {
-  return -std::numeric_limits<float>::infinity();
+  return -HUGE_VALF;
 }
 /*! \brief negative infinity value of double */
 template<>
 MSHADOW_XINLINE double NegInfValue<double>(void) {
-  return -std::numeric_limits<double>::infinity();
+  return -HUGE_VAL;
 }
 
 /*!
@@ -717,12 +717,12 @@ MSHADOW_XINLINE DType PosInfValue(void) {
 /*! \brief positive infinity value of float */
 template<>
 MSHADOW_XINLINE float PosInfValue<float>(void) {
-  return std::numeric_limits<float>::infinity();
+  return HUGE_VALF;
 }
 /*! \brief positive infinity value of double */
 template<>
 MSHADOW_XINLINE double PosInfValue<double>(void) {
-  return std::numeric_limits<double>::infinity();
+  return HUGE_VAL;
 }
 
 }  // namespace limits