Add BF16 support to reference model

* Upgrade Eigen to 3.4.0 (for bfloat16 support) and add work-
  arounds for reduce.any() and reduce.all() bugs (introduced
  between 3.3.7 and 3.4.0)
* Truncation to bfloat16 now performed in eval() methods

Signed-off-by: James Ward <james.ward@arm.com>
Signed-off-by: Jeremy Johnson <jeremy.johnson@arm.com>
Change-Id: If5f5c988d76d3d30790acf3b97081726b89205fe

1 files changed, 29 insertions, 7 deletions

diff --git a/reference_model/src/tensor.cc b/reference_model/src/tensor.cc
index 8d192ca..4eaf21d 100644
--- a/reference_model/src/tensor.cc
+++ b/reference_model/src/tensor.cc
@@ -90,10 +90,12 @@ int TosaReference::Tensor::readFromNpyFile(const char* filename)
     int64_t* i64databuf = nullptr;
     bool* bdatabuf      = nullptr;
     NumpyUtilities::NPError nperror;
+    DType dtype = getDtype();
 
-    switch (getDtype())
+    switch (dtype)
     {
         case DType_FP32:
+        case DType_BF16:
             fdatabuf = (float*)calloc(sizeof(float), elements);
             ASSERT_MEM(fdatabuf);
 
@@ -154,19 +156,38 @@ int TosaReference::Tensor::readFromNpyFile(const char* filename)
             FATAL_ERROR("Unknown error parsing Numpy file: %s", filename);
     }
 
-    switch (getDtype())
+    switch (dtype)
     {
         case DType_FP16:
             // Convert from fp16 to fp32
+            //TODO(jw): remove this once we cast to fp16 in register_fcn/eval
             for (uint32_t i=0; i < elements; i++) {
                 fdatabuf[i] = half_float::half_cast<float, half_float::half>(f16databuf[i]);
             }
-            // Fall through to DType_FP32 case
+            if (setTensorValueFloat(elements, fdatabuf))
+            {
+                free(f16databuf);
+                free(fdatabuf);
+                return 1;
+            }
+            break;
+        case DType_BF16:
+            for (uint32_t i=0; i < elements; i++)
+            {
+                ASSERT_MSG(
+                    checkValidBFloat(fdatabuf[i]),
+                    "Input float value not a valid bfloat16 value."
+                );
+            }
+            if (setTensorValueFloat(elements, fdatabuf))
+            {
+                free(fdatabuf);
+                return 1;
+            }
+            break;
         case DType_FP32:
             if (setTensorValueFloat(elements, fdatabuf))
             {
-                if (f16databuf)
-                    free(f16databuf);
                 free(fdatabuf);
                 return 1;
             }
@@ -226,10 +247,12 @@ int TosaReference::Tensor::writeToNpyFile(const char* filename) const
     bool* bdatabuf      = nullptr;
     NumpyUtilities::NPError nperror;
     uint32_t elements = getElementCount();
+    DType dtype = getDtype();
 
-    switch (getDtype())
+    switch (dtype)
     {
         case DType_FP32:
+        case DType_BF16:
             fdatabuf = (float*)calloc(sizeof(float), elements);
             ASSERT_MEM(fdatabuf);
 
@@ -238,7 +261,6 @@ int TosaReference::Tensor::writeToNpyFile(const char* filename) const
                 free(fdatabuf);
                 return 1;
             }
-
             nperror = NumpyUtilities::writeToNpyFile(filename, shape, fdatabuf);
 
             free(fdatabuf);