Add rounding for float to bf16 conversion as default (#1812)

* Add rounding for float to bf16 conversion

* Add bhalf test

* Add inf test bhalf

* Refactor

* update cmake

* Fixes

[ROCm/composable_kernel commit: 7790e8c3f7]

test/data_type/CMakeLists.txt

@@ -49,3 +49,4 @@ if(result EQUAL 0)
 endif()
 
 add_gtest_executable(test_type_convert_const type_convert_const.cpp)
+add_gtest_executable(test_bhalf test_bhalf.cpp)

test/data_type/test_bhalf.cpp

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2025, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "gtest/gtest.h"
+#include "ck/utility/data_type.hpp"
+#include "ck/utility/type_convert.hpp"
+
+using ck::bhalf_t;
+using ck::type_convert;
+
+TEST(BHALF_T, Nan)
+{
+    const uint16_t binary_bhalf_nan = 0x7FC0;
+    const bhalf_t bhalf_nan         = ck::bit_cast<bhalf_t>(binary_bhalf_nan);
+    EXPECT_EQ(bhalf_nan, type_convert<bhalf_t>(ck::NumericLimits<float>::QuietNaN()));
+}
+
+TEST(BHALF_T, Inf)
+{
+    const uint16_t binary_bhalf_inf = 0x7F80;
+    const bhalf_t bhalf_inf         = ck::bit_cast<bhalf_t>(binary_bhalf_inf);
+    EXPECT_EQ(bhalf_inf, type_convert<bhalf_t>(ck::NumericLimits<float>::Infinity()));
+}
+
+TEST(BHALF_T, MantisaOverflow)
+{
+    const float abs_tol   = std::pow(2, -7);
+    const uint32_t val    = 0x81FFFFFF;
+    const float float_val = ck::bit_cast<float>(val);
+
+    ASSERT_NEAR(float_val, type_convert<float>(type_convert<bhalf_t>(float_val)), abs_tol);
+}
+
+TEST(BHALF_T, ExpOverflow)
+{
+    const uint32_t val    = 0xFF800000;
+    const float float_val = ck::bit_cast<float>(val);
+    ASSERT_EQ(type_convert<float>(type_convert<bhalf_t>(float_val)), float_val);
+}
+
+TEST(BHALF_T, MantisaExpOverflow)
+{
+    const uint32_t val    = 0xFFFFFFFF;
+    const float float_val = ck::bit_cast<float>(val);
+
+    ASSERT_TRUE(std::isnan(float_val));
+    ASSERT_TRUE(std::isnan(type_convert<float>(type_convert<bhalf_t>(float_val))));
+}