IVGCVSW-4517 Implement BFloat16 Encoder and Decoder

 * Add ConvertFloat32ToBFloat16
 * Add ConvertBFloat16ToFloat32
 * Add BFloat16Encoder
 * Add BFloat16Decoder
 * Unit tests

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: I198888384c923aba28cfbed09a02edc6f8194b3e

1 files changed, 70 insertions, 0 deletions

diff --git a/src/armnn/test/FloatingPointConverterTest.cpp b/src/armnn/test/FloatingPointConverterTest.cpp
index 4497ca70a8..4a9e216e70 100644
--- a/src/armnn/test/FloatingPointConverterTest.cpp
+++ b/src/armnn/test/FloatingPointConverterTest.cpp
@@ -5,6 +5,7 @@
 
 #include <armnnUtils/FloatingPointConverter.hpp>
 
+#include <BFloat16.hpp>
 #include <Half.hpp>
 
 #include <boost/test/unit_test.hpp>
@@ -52,4 +53,73 @@ BOOST_AUTO_TEST_CASE(TestConvertFp16ToFp32)
     }
 }
 
+BOOST_AUTO_TEST_CASE(TestConvertFloat32ToBFloat16)
+{
+    float floatArray[] = { 1.704735E38f,   // 0x7F004000 round down
+                           0.0f,           // 0x00000000 round down
+                           2.2959E-41f,    // 0x00004000 round down
+                           1.7180272E38f,  // 0x7F014000 round down
+                           9.18355E-41f,   // 0x00010000 round down
+                           1.14794E-40f,   // 0x00014000 round down
+                           4.5918E-41f,    // 0x00008000 round down
+                           -1.708058E38f,  // 0xFF008000 round down
+                           -4.3033756E37f, // 0xFE018000 round up
+                           1.60712E-40f,   // 0x0001C000 round up
+                           -2.0234377f,    // 0xC0018001 round up
+                           -1.1800863E-38f,// 0x80808001 round up
+                           4.843037E-35f,  // 0x0680C000 round up
+                           3.9999998f,     // 0x407FFFFF round up
+                           3.4028235E38f,  // 0x7F7FFFFF max positive value
+                           -3.4028235E38f, // 0xFF7FFFFF max negative value
+                           1.1754942E-38f, // 0x007FFFFF min positive value
+                           -1.1754942E-38f // 0x807FFFFF min negative value
+                          };
+    uint16_t expectedResult[] = { 0x7F00,
+                                  0x0000,
+                                  0x0000,
+                                  0x7F01,
+                                  0x0001,
+                                  0x0001,
+                                  0x0000,
+                                  0xFF00,
+                                  0xFE02,
+                                  0x0002,
+                                  0xC002,
+                                  0x8081,
+                                  0x0681,
+                                  0x4080,
+                                  0x7F80,
+                                  0xFF80,
+                                  0x0080,
+                                  0x8080
+                                 };
+    size_t numFloats = sizeof(floatArray) / sizeof(floatArray[0]);
+
+    std::vector<armnn::BFloat16> convertedBuffer(numFloats);
+
+    armnnUtils::FloatingPointConverter::ConvertFloat32ToBFloat16(floatArray, numFloats, convertedBuffer.data());
+
+    for (size_t i = 0; i < numFloats; i++)
+    {
+        armnn::BFloat16 actual = convertedBuffer[i];
+        BOOST_CHECK_EQUAL(expectedResult[i], actual.val());
+    }
+}
+
+BOOST_AUTO_TEST_CASE(TestConvertBFloat16ToFloat32)
+{
+    uint16_t bf16Array[] = { 16256, 16320, 38699, 16384, 49156, 32639 };
+    size_t numFloats = sizeof(bf16Array) / sizeof(bf16Array[0]);
+    float expectedResult[] = { 1.0f, 1.5f, -5.525308E-25f, 2.0f, -2.0625f, 3.3895314E38f };
+    std::vector<float> convertedBuffer(numFloats, 0.0f);
+
+    armnnUtils::FloatingPointConverter::ConvertBFloat16ToFloat32(bf16Array, numFloats, convertedBuffer.data());
+
+    for (size_t i = 0; i < numFloats; i++)
+    {
+        float actual = convertedBuffer[i];
+        BOOST_CHECK_EQUAL(expectedResult[i], actual);
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()