1 files changed, 144 insertions, 0 deletions
diff --git a/src/cpu/kernels/cast/generic/neon/bfloat16.cpp b/src/cpu/kernels/cast/generic/neon/bfloat16.cpp
new file mode 100644
index 0000000000..b15584b0aa
--- /dev/null
+++ b/src/cpu/kernels/cast/generic/neon/bfloat16.cpp
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2016-2022 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#if defined(__ARM_FEATURE_BF16_VECTOR_ARITHMETIC) || defined(ARM_COMPUTE_FORCE_BF16)
+
+#include "arm_compute/core/TensorInfo.h"
+#include "src/cpu/kernels/CpuCastKernel.h"
+#include "src/cpu/kernels/cast/list.h"
+#include "support/SaturateCast.h"
+
+namespace arm_compute
+{
+namespace cpu
+{
+void neon_fp32_to_bfloat16_cast(const ITensor *_src, ITensor *_dst, const ThreadInfo &info, ConvertPolicy _policy, const Window &window)
+{
+    ARM_COMPUTE_UNUSED(info);
+    ARM_COMPUTE_UNUSED(_policy);
+
+    const auto window_start_x = static_cast<int>(window.x().start());
+    const auto window_end_x   = static_cast<int>(window.x().end());
+    const int  window_step_x  = 16;
+
+    ARM_COMPUTE_ERROR_ON_NULLPTR(_src, _dst);
+    ARM_COMPUTE_ERROR_ON(_src == _dst);
+
+    ARM_COMPUTE_ERROR_ON_NULLPTR(_src, _dst);
+
+    Window win{ window };
+    win.set(Window::DimX, Window::Dimension(0, 1, 1));
+
+    Iterator src(_src, win);
+    Iterator dst(_dst, win);
+
+    /* Down-conversion F32 -> BFLOAT16 */
+    execute_window_loop(win, [&](const Coordinates &)
+    {
+        const auto src_ptr = reinterpret_cast<const float *>(src.ptr());
+        const auto dst_ptr = reinterpret_cast<bfloat16 *>(dst.ptr());
+
+        int x = window_start_x;
+        for(; x <= (window_end_x - window_step_x); x += window_step_x)
+        {
+            wrapper::vcvt_bf16_f32(reinterpret_cast<float *>(src.ptr()),
+                                   reinterpret_cast<uint16_t *>(dst.ptr()));
+            wrapper::vcvt_bf16_f32(reinterpret_cast<float *>(src.ptr()) + 8,
+                                   reinterpret_cast<uint16_t *>(dst.ptr()) + 8);
+        }
+
+        for(; x < window_end_x; ++x)
+        {
+            *(dst_ptr + x) = *(src_ptr + x);
+        }
+    },
+    src, dst);
+}
+
+void neon_bfloat16_to_fp32_cast(const ITensor *_src, ITensor *_dst, const ThreadInfo &info, ConvertPolicy _policy, const Window &window)
+{
+    ARM_COMPUTE_UNUSED(info);
+    ARM_COMPUTE_UNUSED(_policy);
+
+    const auto window_start_x = static_cast<int>(window.x().start());
+    const auto window_end_x   = static_cast<int>(window.x().end());
+    const int  window_step_x  = 16;
+
+    ARM_COMPUTE_ERROR_ON_NULLPTR(_src, _dst);
+    ARM_COMPUTE_ERROR_ON(_src == _dst);
+
+    ARM_COMPUTE_ERROR_ON_NULLPTR(_src, _dst);
+
+    Window win{ window };
+    win.set(Window::DimX, Window::Dimension(0, 1, 1));
+
+    Iterator src(_src, win);
+    Iterator dst(_dst, win);
+    switch(_dst->info()->data_type())
+    {
+        case DataType::F32:
+        {
+            /* Up-conversion BFLOAT16 -> F32 */
+            execute_window_loop(win, [&](const Coordinates &)
+            {
+                const auto src_ptr = reinterpret_cast<const bfloat16 *>(src.ptr());
+                const auto dst_ptr = reinterpret_cast<float *>(dst.ptr());
+
+                int x = window_start_x;
+                for(; x <= (window_end_x - window_step_x); x += window_step_x)
+                {
+                    const uint16x8x2_t texels =
+                    {
+                        {
+                            vld1q_u16(reinterpret_cast<uint16_t *>(src.ptr())),
+                            vld1q_u16(reinterpret_cast<uint16_t *>(src.ptr()) + 8)
+                        }
+                    };
+
+                    vst1q_f32(reinterpret_cast<float *>(dst.ptr()),
+                              vreinterpretq_f32_u32(vshlq_n_u32(vmovl_u16(vget_low_u16(texels.val[0])), 16)));
+                    vst1q_f32(reinterpret_cast<float *>(dst.ptr()) + 4,
+                              vreinterpretq_f32_u32(vshlq_n_u32(vmovl_u16(vget_high_u16(texels.val[0])), 16)));
+                    vst1q_f32(reinterpret_cast<float *>(dst.ptr()) + 8,
+                              vreinterpretq_f32_u32(vshlq_n_u32(vmovl_u16(vget_low_u16(texels.val[1])), 16)));
+                    vst1q_f32(reinterpret_cast<float *>(dst.ptr()) + 12,
+                              vreinterpretq_f32_u32(vshlq_n_u32(vmovl_u16(vget_high_u16(texels.val[1])), 16)));
+                }
+
+                for(; x < window_end_x; ++x)
+                {
+                    *(dst_ptr + x) = float(*(src_ptr + x));
+                }
+            },
+            src, dst);
+            break;
+        }
+        default:
+            ARM_COMPUTE_ERROR("dst data type unsupported");
+    }
+}
+
+} // namespace cpu
+} // namespace arm_compute
+
+#endif /* defined(__ARM_FEATURE_BF16_VECTOR_ARITHMETIC) || defined(ARM_COMPUTE_FORCE_BF16) */