COMPMID-455 - Optimizing CLIm2ColKernel

Change-Id: Iee618948cc8f310ee9af2d786240e8120e4c6ab9
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/81665
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/src/core/CL/CLKernelLibrary.cpp b/src/core/CL/CLKernelLibrary.cpp
index 8f6ec20..9c8be36 100644
--- a/src/core/CL/CLKernelLibrary.cpp
+++ b/src/core/CL/CLKernelLibrary.cpp
@@ -187,6 +187,7 @@
     { "hog_orientation_binning", "hog.cl" },
     { "hysteresis", "canny.cl" },
     { "im2col_generic", "convolution_layer.cl" },
+    { "im2col_kernel3x3_padx0_pady0", "convolution_layer.cl" },
     { "im2col_reduced", "convolution_layer.cl" },
     { "init_level", "optical_flow_pyramid_lk.cl" },
     { "init_level_max", "optical_flow_pyramid_lk.cl" },
diff --git a/src/core/CL/cl_kernels/convolution_layer.cl b/src/core/CL/cl_kernels/convolution_layer.cl
index a875911..7eb04c7 100644
--- a/src/core/CL/cl_kernels/convolution_layer.cl
+++ b/src/core/CL/cl_kernels/convolution_layer.cl
@@ -21,9 +21,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-#include "fixed_point.h"
 #include "helpers.h"
 
+#if defined(FIXED_POINT_POSITION)
+#include "fixed_point.h"
+#endif // FIXED_POINT_POSITION
+
 /** This kernel reshapes the tensor's low three dimensions to single column
  *
  * @note Datatype should be given as a preprocessor argument using -DDATA_TYPE=type. e.g. -DDATA_TYPE=short
@@ -100,7 +103,7 @@
  * @note The data type must be passed at compile time using -DDATA_TYPE: e.g. -DDATA_TYPE=float
  * @note In case biases will be added to the convolution -DHAS_BIAS has to be passed to append the final matrix with 1 in each row.
  *
- * @param[in]  src_ptr                           Pointer to the source tensor. Supported data types: QS8/F16/F32
+ * @param[in]  src_ptr                           Pointer to the source tensor. Supported data types: QS8/QS16/F16/F32
  * @param[in]  src_stride_x                      Stride of the source tensor in X dimension (in bytes)
  * @param[in]  src_step_x                        src_stride_x * number of elements along X processed per workitem(in bytes)
  * @param[in]  src_stride_y                      Stride of the source tensor in Y dimension (in bytes)
@@ -119,42 +122,112 @@
     TENSOR3D_DECLARATION(src),
     IMAGE_DECLARATION(dst))
 {
-    Tensor3D src = CONVERT_TO_TENSOR3D_STRUCT(src);
-    Image    dst = CONVERT_TO_IMAGE_STRUCT_NO_STEP(dst);
+    const int xc = get_global_id(0); // x coordinate in the convolved tensor
+    const int yc = get_global_id(1); // y coordinate in the convolved tensor
+    const int ch = get_global_id(2); // input feature map
 
-    // Determine output index
-    uint     idx               = (get_global_id(1) * CONVOLVED_WIDTH + get_global_id(0)) * dst.stride_y;
-    __global uchar *output_ptr = dst.ptr + idx;
+    // Calculate input indeces
+    const int xi = xc * STRIDE_X - PAD_X;
+    const int yi = yc * STRIDE_Y - PAD_Y;
 
-    // Determine current input index
-    const int top_left_x = get_global_id(0) * STRIDE_X - PAD_X;
-    const int top_left_y = get_global_id(1) * STRIDE_Y - PAD_Y;
+    // Calculate output indeces
+    const int xo = ch * KERNEL_WIDTH * KERNEL_HEIGHT;
+    const int yo = xc + yc * CONVOLVED_WIDTH; // Index of the convolution
+
+    __global uchar *input_ptr      = src_ptr + src_offset_first_element_in_bytes + ch * src_stride_z;
+    __global DATA_TYPE *output_ptr = ((__global DATA_TYPE *)(dst_ptr + dst_offset_first_element_in_bytes + yo * dst_stride_y)) + xo;
 
     // Linearize convolution elements
-    for(int d = 0; d < KERNEL_DEPTH; ++d)
+    for(int y = yi, y_e = yi + KERNEL_HEIGHT; y < y_e; ++y)
     {
-        for(int y = top_left_y, y_e = top_left_y + KERNEL_HEIGHT; y < y_e; ++y)
+        for(int x = xi, x_e = xi + KERNEL_WIDTH; x < x_e; ++x, ++output_ptr)
         {
-            for(int x = top_left_x, x_e = top_left_x + KERNEL_WIDTH; x < x_e; ++x, output_ptr += dst.stride_x)
+#if PAD_X == 0 && PAD_Y == 0
+            *output_ptr = *((__global DATA_TYPE *)(input_ptr + x * src_stride_x + y * src_stride_y));
+#else  // PAD_X == 0 && PAD_Y == 0
+            if(x < 0 || x >= SRC_WIDTH || y < 0 || y >= SRC_HEIGHT)
             {
-                if(x < 0 || x >= SRC_WIDTH || y < 0 || y >= SRC_HEIGHT)
-                {
-                    *((__global DATA_TYPE *)output_ptr) = 0;
-                }
-                else
-                {
-                    *((__global DATA_TYPE *)output_ptr) = *((__global DATA_TYPE *)(tensor3D_offset(&src, x, y, d)));
-                }
+                *output_ptr = 0;
             }
+            else
+            {
+                *output_ptr = *((__global DATA_TYPE *)(input_ptr + x * src_stride_x + y * src_stride_y));
+            }
+#endif // PAD_X == 0 && PAD_Y == 0
         }
     }
 
 #ifdef HAS_BIAS
+    if(get_global_id(2) == (KERNEL_DEPTH - 1))
+    {
 #ifdef FIXED_POINT_POSITION
-    *((__global DATA_TYPE *)output_ptr) = (DATA_TYPE)(1 << FIXED_POINT_POSITION);
+        *output_ptr = (DATA_TYPE)(1 << FIXED_POINT_POSITION);
 #else  // FIXED_POINT_POSITION
-    *((__global DATA_TYPE *)output_ptr) = 1.0f;
+        *output_ptr       = 1.0f;
 #endif // FIXED_POINT_POSITION
+    }
+#endif // HAS_BIAS
+}
+
+/** This kernel performs a reshaping of the input tensor to a tensor used to perform convolution using GEMM when the kernel size is 3x3 and pad_x = pad_y = 0
+ *
+ * @note The data type must be passed at compile time using -DDATA_TYPE: e.g. -DDATA_TYPE=float
+ * @note In case biases will be added to the convolution -DHAS_BIAS has to be passed to append the final matrix with 1 in each row.
+ *
+ * @param[in]  src_ptr                           Pointer to the source tensor. Supported data types: QS8/QS16/F16/F32
+ * @param[in]  src_stride_x                      Stride of the source tensor in X dimension (in bytes)
+ * @param[in]  src_step_x                        src_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  src_stride_y                      Stride of the source tensor in Y dimension (in bytes)
+ * @param[in]  src_step_y                        src_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  src_stride_z                      Stride of the source tensor in Z dimension (in bytes)
+ * @param[in]  src_step_z                        src_stride_z * number of elements along Z processed per workitem(in bytes)
+ * @param[in]  src_offset_first_element_in_bytes The offset of the first element in the source tensor
+ * @param[out] dst_ptr                           Pointer to the destination tensor. Supported data types: same as @p src_ptr
+ * @param[in]  dst_stride_x                      Stride of the destination tensor in X dimension (in bytes)
+ * @param[in]  dst_step_x                        dst_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  dst_stride_y                      Stride of the destination tensor in Y dimension (in bytes)
+ * @param[in]  dst_step_y                        dst_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  dst_offset_first_element_in_bytes The offset of the first element in the destination tensor
+ */
+__kernel void im2col_kernel3x3_padx0_pady0(
+    TENSOR3D_DECLARATION(src),
+    IMAGE_DECLARATION(dst))
+{
+    const int xc = get_global_id(0); // x coordinate in the convolved tensor
+    const int yc = get_global_id(1); // y coordinate in the convolved tensor
+    const int ch = get_global_id(2); // input feature map
+
+    // Calculate input indeces
+    const int xi = xc * STRIDE_X;
+    const int yi = yc * STRIDE_Y;
+
+    // Calculate output indeces
+    const int xo = ch * KERNEL_WIDTH * KERNEL_HEIGHT;
+    const int yo = xc + yc * CONVOLVED_WIDTH; // Index of the convolution
+
+    // Get input and output address
+    __global uchar *input_ptr      = src_ptr + src_offset_first_element_in_bytes + xi * src_stride_x + yi * src_stride_y + ch * src_stride_z;
+    __global DATA_TYPE *output_ptr = ((__global DATA_TYPE *)(dst_ptr + dst_offset_first_element_in_bytes + yo * dst_stride_y)) + xo;
+
+    VEC_DATA_TYPE(DATA_TYPE, 3)
+    row0 = vload3(0, (__global DATA_TYPE *)(input_ptr + 0 * src_stride_y));
+    VEC_DATA_TYPE(DATA_TYPE, 3)
+    row1 = vload3(0, (__global DATA_TYPE *)(input_ptr + 1 * src_stride_y));
+    VEC_DATA_TYPE(DATA_TYPE, 3)
+    row2 = vload3(0, (__global DATA_TYPE *)(input_ptr + 2 * src_stride_y));
+
+    vstore8((VEC_DATA_TYPE(DATA_TYPE, 8))(row0.s012, row1.s012, row2.s01), 0, output_ptr);
+    *(output_ptr + 8) = row2.s2;
+
+#ifdef HAS_BIAS
+    if(get_global_id(2) == (KERNEL_DEPTH - 1))
+    {
+#ifdef FIXED_POINT_POSITION
+        *(output_ptr + 9) = (DATA_TYPE)(1 << FIXED_POINT_POSITION);
+#else  // FIXED_POINT_POSITION
+        *(output_ptr + 9) = 1.0f;
+#endif // FIXED_POINT_POSITION
+    }
 #endif // HAS_BIAS
 }
 #endif //defined(CONVOLVED_WIDTH) && defined(STRIDE_X) && defined(STRIDE_Y) && defined(PAD_X) && defined(PAD_Y) && defined(KERNEL_WIDTH) && defined(KERNEL_HEIGHT) && defined(KERNEL_DEPTH) && defined(SRC_WIDTH) && defined(SRC_HEIGHT)
@@ -163,7 +236,7 @@
  *
  * @note The data type must be passed at compile time using -DDATA_TYPE: e.g. -DDATA_TYPE=float
  *
- * @param[in]  src_ptr                           Pointer to the source tensor. Supported data types: QS8/F16/F32
+ * @param[in]  src_ptr                           Pointer to the source tensor. Supported data types: QS8/QS16/F16/F32
  * @param[in]  src_stride_x                      Stride of the source tensor in X dimension (in bytes)
  * @param[in]  src_step_x                        src_stride_x * number of elements along X processed per workitem(in bytes)
  * @param[in]  src_stride_y                      Stride of the source tensor in Y dimension (in bytes)
diff --git a/src/core/CL/cl_kernels/fixed_point.h b/src/core/CL/cl_kernels/fixed_point.h
index 4de7fc5..509e9d0 100644
--- a/src/core/CL/cl_kernels/fixed_point.h
+++ b/src/core/CL/cl_kernels/fixed_point.h
@@ -54,6 +54,7 @@
 #define qs8_TYPE char
 #define qs8x1_TYPE char
 #define qs8x2_TYPE char2
+#define qs8x3_TYPE char3
 #define qs8x4_TYPE char4
 #define qs8x8_TYPE char8
 #define qs8x16_TYPE char16
@@ -61,6 +62,7 @@
 #define qs16_TYPE short
 #define qs16x1_TYPE short
 #define qs16x2_TYPE short2
+#define qs16x3_TYPE short3
 #define qs16x4_TYPE short4
 #define qs16x8_TYPE short8
 #define qs16x16_TYPE short16
@@ -68,6 +70,7 @@
 #define qs32_TYPE int
 #define qs32x1_TYPE int
 #define qs32x2_TYPE int2
+#define qs32x3_TYPE int3
 #define qs32x4_TYPE int4
 #define qs32x8_TYPE int8
 #define qs32x16_TYPE int16
diff --git a/src/core/CL/cl_kernels/helpers.h b/src/core/CL/cl_kernels/helpers.h
index 4122112..59b81d7 100644
--- a/src/core/CL/cl_kernels/helpers.h
+++ b/src/core/CL/cl_kernels/helpers.h
@@ -245,7 +245,7 @@
 
 /** Get the pointer position of a Tensor3D
  *
- * @param[in] tensor Pointer to the starting postion of the buffer
+ * @param[in] tensor Pointer to the starting position of the buffer
  * @param[in] x      Relative X position
  * @param[in] y      Relative Y position
  * @param[in] z      Relative Z position
diff --git a/src/core/CL/kernels/CLCol2ImKernel.cpp b/src/core/CL/kernels/CLCol2ImKernel.cpp
index cfbe740..ddcc3fa 100644
--- a/src/core/CL/kernels/CLCol2ImKernel.cpp
+++ b/src/core/CL/kernels/CLCol2ImKernel.cpp
@@ -53,7 +53,12 @@
 
     // Create kernel
     std::set<std::string> build_opts = { ("-DDATA_TYPE=" + get_cl_type_from_data_type(input->info()->data_type())) };
-    _kernel                          = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("col2im", build_opts));
+    if(is_data_type_fixed_point(input->info()->data_type()))
+    {
+        build_opts.emplace("-DFIXED_POINT_POSITION=" + support::cpp11::to_string(input->info()->fixed_point_position()));
+    }
+
+    _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("col2im", build_opts));
 
     // Set static kernel arguments
     unsigned int idx = num_arguments_per_2D_tensor() + num_arguments_per_3D_tensor();
diff --git a/src/core/CL/kernels/CLIm2ColKernel.cpp b/src/core/CL/kernels/CLIm2ColKernel.cpp
index 7d7732d..b72aff2 100644
--- a/src/core/CL/kernels/CLIm2ColKernel.cpp
+++ b/src/core/CL/kernels/CLIm2ColKernel.cpp
@@ -87,6 +87,7 @@
         build_opts.emplace("-DKERNEL_HEIGHT=" + support::cpp11::to_string(kernel_dims.height));
         build_opts.emplace("-DKERNEL_DEPTH=" + support::cpp11::to_string(input->info()->dimension(2)));
         build_opts.emplace("-DCONVOLVED_WIDTH=" + support::cpp11::to_string(_convolved_dims.first));
+        build_opts.emplace("-DCONVOLVED_HEIGHT=" + support::cpp11::to_string(_convolved_dims.second));
         build_opts.emplace("-DSTRIDE_X=" + support::cpp11::to_string(conv_info.stride().first));
         build_opts.emplace("-DSTRIDE_Y=" + support::cpp11::to_string(conv_info.stride().second));
         build_opts.emplace("-DPAD_X=" + support::cpp11::to_string(conv_info.pad().first));
@@ -94,7 +95,14 @@
         build_opts.emplace("-DSRC_WIDTH=" + support::cpp11::to_string(input->info()->dimension(0)));
         build_opts.emplace("-DSRC_HEIGHT=" + support::cpp11::to_string(input->info()->dimension(1)));
 
-        _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("im2col_generic", build_opts));
+        if(kernel_dims.width == 3 && kernel_dims.height == 3 && conv_info.pad().first == 0 && conv_info.pad().second == 0)
+        {
+            _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("im2col_kernel3x3_padx0_pady0", build_opts));
+        }
+        else
+        {
+            _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("im2col_generic", build_opts));
+        }
 
         _run_func = &CLIm2ColKernel::run_generic;
     }
@@ -131,7 +139,7 @@
     // Setup slice
     slice.set(Window::DimX, Window::Dimension(0, static_cast<int>(_convolved_dims.first), 1));
     slice.set(Window::DimY, Window::Dimension(0, static_cast<int>(_convolved_dims.second), 1));
-    slice.set(Window::DimZ, Window::Dimension(0, 1, 1));
+    slice.set(Window::DimZ, Window::Dimension(0, static_cast<int>(_input->info()->dimension(2)), 1));
 
     // Setup input slice
     // The first three dimensions of the input are increased by the inner loops
@@ -144,13 +152,16 @@
     slice_out.set(Window::DimY, Window::Dimension(0, _output->info()->dimension(1), 1));
     slice_out.set(Window::DimZ, Window::Dimension(0, 1, 1));
 
+    // Set the local-workgroup size
+    _lws_hint = cl::NDRange(4, 4, 4);
+
     do
     {
         // Set inputs
         unsigned int idx = 0;
         add_3D_tensor_argument(idx, _input, slice_in);
         add_2D_tensor_argument(idx, _output, slice_out);
-        enqueue(queue, *this, slice);
+        enqueue(queue, *this, slice, _lws_hint);
     }
     while(window.slide_window_slice_3D(slice) && window.slide_window_slice_3D(slice_out) && window.slide_window_slice_3D(slice_in));
 }
diff --git a/src/core/CL/kernels/CLWeightsReshapeKernel.cpp b/src/core/CL/kernels/CLWeightsReshapeKernel.cpp
index b802c86..7b80f3f 100644
--- a/src/core/CL/kernels/CLWeightsReshapeKernel.cpp
+++ b/src/core/CL/kernels/CLWeightsReshapeKernel.cpp
@@ -78,6 +78,10 @@
     std::set<std::string> build_opts;
     build_opts.emplace(("-DDATA_TYPE=" + get_cl_type_from_data_type(input->info()->data_type())));
     build_opts.emplace(((biases != nullptr) ? "-DHAS_BIAS" : ""));
+    if(is_data_type_fixed_point(input->info()->data_type()))
+    {
+        build_opts.emplace("-DFIXED_POINT_POSITION=" + support::cpp11::to_string(input->info()->fixed_point_position()));
+    }
 
     // Create kernel
     _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel("reshape_to_columns", build_opts));