commit 07098d64498723e889e8f8deaad4952020fa9450
author Won Jeon <won.jeon@arm.com> Thu May 09 06:00:31 2024 +0000
committer Won Jeon <won.jeon@arm.com> Thu May 09 18:21:17 2024 +0000
tree 94f4bd6a070c73bbd629118fe6bfd8390bdf7213
parent b386815fcf36092be832281821af7ad9f2119e07

Fix Bfloat16 data conversion for serialization

Signed-off-by: Won Jeon <won.jeon@arm.com>
Change-Id: I52f6fea3e8b4cd5ff0886ccfa12396a680558670

python/serializer/tosa_serializer.py

diff --git a/python/serializer/tosa_serializer.py b/python/serializer/tosa_serializer.py
index 7122216..34178c5 100644
--- a/python/serializer/tosa_serializer.py
+++ b/python/serializer/tosa_serializer.py
@@ -947,9 +947,8 @@
             np_arr = np.array(data, dtype=np.float32)
             u8_data.extend(np_arr.view(np.uint8))
         elif dtype == DType.BF16:
-            for val in data:
-                np_arr = np.array(data, dtype=bfloat16)
-                u8_data.extend(np_arr.view(np.uint8))
+            np_arr = np.array(data, dtype=bfloat16)
+            u8_data.extend(np_arr.view(np.uint8))
         elif dtype == DType.FP8E4M3:
             for val in data:
                 val_f8 = np.array(val).astype(float8_e4m3fn).view(np.uint8)

src/tosa_serialization_handler.cpp

diff --git a/src/tosa_serialization_handler.cpp b/src/tosa_serialization_handler.cpp
index 76b2198..4516f7d 100644
--- a/src/tosa_serialization_handler.cpp
+++ b/src/tosa_serialization_handler.cpp
@@ -940,7 +940,6 @@
 tosa_err_t
     TosaSerializationHandler::ConvertU8toBF16(const std::vector<uint8_t>& in, uint32_t out_size, std::vector<bf16>& out)
 {
-    // Note: bf16 values returned in fp32 type
     out.clear();
     if (in.size() < out_size * sizeof(int16_t))
     {
@@ -951,13 +950,12 @@
 
     for (uint32_t i = 0; i < out_size; i++)
     {
-        uint32_t f32_byte2 = in[i * sizeof(int16_t)];
-        uint32_t f32_byte3 = in[i * sizeof(int16_t) + 1];
-        uint32_t val_u32   = (f32_byte2 << 16) + (f32_byte3 << 24);
+        uint8_t bf16_byte0 = in[i * sizeof(int16_t)];
+        uint8_t bf16_byte1 = in[i * sizeof(int16_t) + 1];
+        uint16_t val_u16   = (bf16_byte0) + (bf16_byte1 << 8);
 
-        // Reinterpret u32 bytes as fp32
-        float val_f32  = *(float*)&val_u32;
-        float val_bf16 = static_cast<bf16>(val_f32);
+        // Reinterpret u16 bytes as bf16
+        bf16 val_bf16 = static_cast<bf16>(val_u16);
         out.push_back(val_bf16);
     }
     return TOSA_OK;
@@ -1021,9 +1019,9 @@
 
     for (uint32_t i = 0; i < out_size; i++)
     {
-        uint16_t f16_byte0 = in[i * sizeof(int16_t)];
-        uint16_t f16_byte1 = in[i * sizeof(int16_t) + 1];
-        uint16_t val_u16   = f16_byte0 + (f16_byte1 << 8);
+        uint8_t f16_byte0 = in[i * sizeof(int16_t)];
+        uint8_t f16_byte1 = in[i * sizeof(int16_t) + 1];
+        uint16_t val_u16  = f16_byte0 + (f16_byte1 << 8);
 
         // Reinterpret u16 byte as fp16 then convert to fp32
         half_float::half val_f16 = *(half_float::half*)&val_u16;