COMPMID-895 - Optimizing CLDepthwiseConvolution3x3Kernel

This patch brings the MACs utilisation up to 25 % when both stride_x and stride_y are equal to 1
Performance reported in the following confluence page:
https://confluence.arm.com/display/MLENG/Depthwise+convolution+3x3+FP32+performance%3A+ACL+18.02

Change-Id: Ida1b64be9a88805902a3d90194559b58eb1224a3
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/119068
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
Tested-by: Jenkins <bsgcomp@arm.com>

1 files changed, 211 insertions, 8 deletions

diff --git a/src/core/CL/cl_kernels/depthwise_convolution.cl b/src/core/CL/cl_kernels/depthwise_convolution.cl
index 89555a0cb6..ac94b693e3 100644
--- a/src/core/CL/cl_kernels/depthwise_convolution.cl
+++ b/src/core/CL/cl_kernels/depthwise_convolution.cl
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited.
+ * Copyright (c) 2017-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -144,9 +144,9 @@ inline float2 convolution3x3(
     return pixels;
 }
 
-/** This function computes the horizontal integral of the image.
+/** This OpenCL kernel computes the depthwise convolution 3x3
  *
- * @param[in] src_ptr                               Pointer to the source image. Supported data types: U8
+ * @param[in] src_ptr                               Pointer to the source image. Supported data types: F32
  * @param[in] src_stride_x                          Stride of the source image 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 image in Y dimension (in bytes)
@@ -154,7 +154,7 @@ inline float2 convolution3x3(
  * @param[in] src_offset_first_element_in_bytes     The offset of the first element in the source image
  * @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 Y processed per workitem(in bytes)
- * @param[in] dst_ptr                               Pointer to the destination tensor. Supported data types: F16/F32
+ * @param[in] dst_ptr                               Pointer to the destination tensor. Supported data types: F32
  * @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)
@@ -162,7 +162,7 @@ inline float2 convolution3x3(
  * @param[in] dst_stride_z                          Stride of the destination tensor in Z dimension (in bytes)
  * @param[in] dst_step_z                            dst_stride_z * 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
- * @param[in] weights_ptr                           Pointer to the weights tensor. Supported data types: F16/F32
+ * @param[in] weights_ptr                           Pointer to the weights tensor. Supported data types: F32
  * @param[in] weights_stride_x                      Stride of the weights tensor in X dimension (in bytes)
  * @param[in] weights_step_x                        weights_stride_x * number of elements along X processed per workitem(in bytes)
  * @param[in] weights_stride_y                      Stride of the weights tensor in Y dimension (in bytes)
@@ -175,7 +175,6 @@ inline float2 convolution3x3(
  * @param[in] biases_step_x                         (Optional) biases_stride_x * number of elements along X processed per workitem(in bytes)
  * @param[in] biases_offset_first_element_in_bytes  (Optional) The offset of the first element in the biases vector
  */
-
 __kernel void depthwise_convolution_3x3(
     TENSOR3D_DECLARATION(src),
     TENSOR3D_DECLARATION(dst),
@@ -207,9 +206,214 @@ __kernel void depthwise_convolution_3x3(
 
     vstore2(pixels, 0, (__global float *)dst.ptr);
 }
-
 #endif //defined(CONV_STRIDE_X)
 
+#define CONVOLUTION1x3_BIFROST2X1_STRIDE1(acc, src0, weights_row0) \
+    ({                                                             \
+        acc.s0 = fma(src0.s0, weights_row0.s0, acc.s0);            \
+        acc.s0 = fma(src0.s1, weights_row0.s1, acc.s0);            \
+        acc.s0 = fma(src0.s2, weights_row0.s2, acc.s0);            \
+        acc.s1 = fma(src0.s1, weights_row0.s0, acc.s1);            \
+        acc.s1 = fma(src0.s2, weights_row0.s1, acc.s1);            \
+        acc.s1 = fma(src0.s3, weights_row0.s2, acc.s1);            \
+    })
+
+#define CONVOLUTION1x3_BIFROST2X1_STRIDE2(acc, src0, src1, weights_row0) \
+    ({                                                                   \
+        acc.s0 = fma(src0.s0, weights_row0.s0, acc.s0);                  \
+        acc.s0 = fma(src0.s1, weights_row0.s1, acc.s0);                  \
+        acc.s0 = fma(src0.s2, weights_row0.s2, acc.s0);                  \
+        acc.s1 = fma(src0.s2, weights_row0.s0, acc.s1);                  \
+        acc.s1 = fma(src0.s3, weights_row0.s1, acc.s1);                  \
+        acc.s1 = fma(src1.s0, weights_row0.s2, acc.s1);                  \
+    })
+
+/** This OpenCL kernel is optimized for Bifrost architectures and computes the depthwise convolution 3x3 when both
+ * stride_x and stride_y are equal to 1
+ *
+ * @param[in] src_ptr                               Pointer to the source image. Supported data types: F32
+ * @param[in] src_stride_x                          Stride of the source image 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 image 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_offset_first_element_in_bytes     The offset of the first element in the source image
+ * @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 Y processed per workitem(in bytes)
+ * @param[in] dst_ptr                               Pointer to the destination tensor. Supported data types: F32
+ * @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_stride_z                          Stride of the destination tensor in Z dimension (in bytes)
+ * @param[in] dst_step_z                            dst_stride_z * 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
+ * @param[in] weights_ptr                           Pointer to the weights tensor. Supported data types: F32
+ * @param[in] weights_stride_x                      Stride of the weights tensor in X dimension (in bytes)
+ * @param[in] weights_step_x                        weights_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in] weights_stride_y                      Stride of the weights tensor in Y dimension (in bytes)
+ * @param[in] weights_step_y                        weights_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in] weights_stride_z                      Stride of the weights tensor in Z dimension (in bytes)
+ * @param[in] weights_step_z                        weights_stride_z * number of elements along Y processed per workitem(in bytes)
+ * @param[in] weights_offset_first_element_in_bytes The offset of the first element in the biases vector
+ * @param[in] biases_ptr                            (Optional) Pointer to the biases vector. Supported data types: F32
+ * @param[in] biases_stride_x                       (Optional) Stride of the biases vector in X dimension (in bytes)
+ * @param[in] biases_step_x                         (Optional) biases_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in] biases_offset_first_element_in_bytes  (Optional) The offset of the first element in the biases vector
+ */
+__kernel void depthwise_convolution_3x3_stridex1_stridey1_bifrost(
+    TENSOR3D_DECLARATION(src),
+    TENSOR3D_DECLARATION(dst),
+    TENSOR3D_DECLARATION(weights)
+#if defined(HAS_BIAS)
+    ,
+    VECTOR_DECLARATION(biases)
+#endif //defined(HAS_BIAS)
+)
+{
+    Image    src     = CONVERT_TENSOR3D_TO_IMAGE_STRUCT(src);
+    Image    dst     = CONVERT_TENSOR3D_TO_IMAGE_STRUCT(dst);
+    Tensor3D weights = CONVERT_TO_TENSOR3D_STRUCT(weights);
+
+    float2 pixels0 = 0.0f;
+    float2 pixels1 = 0.0f;
+    float2 pixels2 = 0.0f;
+    float2 pixels3 = 0.0f;
+
+    __global uchar *weights_addr = (__global uchar *)weights.ptr;
+    __global uchar *src_addr     = (__global uchar *)offset(&src, 0, 0);
+
+    // Load the weights
+    float3 weights_row0 = vload3(0, (__global float *)(weights_addr + 0 * weights_stride_y));
+    float3 weights_row1 = vload3(0, (__global float *)(weights_addr + 1 * weights_stride_y));
+    float3 weights_row2 = vload3(0, (__global float *)(weights_addr + 2 * weights_stride_y));
+
+    // Note: Since each work-item computes 4x2 elements, we need to load 4 rows from the input tensor
+    float4 src00 = vload4(0, (__global float *)(src_addr + 0 * src_stride_y)); // Row0
+    float4 src10 = vload4(0, (__global float *)(src_addr + 1 * src_stride_y)); // Row1
+    float4 src20 = vload4(0, (__global float *)(src_addr + 2 * src_stride_y)); // Row2
+    float4 src30 = vload4(0, (__global float *)(src_addr + 3 * src_stride_y)); // Row3
+    float4 src40 = vload4(0, (__global float *)(src_addr + 4 * src_stride_y)); // Row3
+    float4 src50 = vload4(0, (__global float *)(src_addr + 5 * src_stride_y)); // Row3
+
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels0, src00, weights_row0);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels0, src10, weights_row1);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels0, src20, weights_row2);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels1, src10, weights_row0);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels1, src20, weights_row1);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels1, src30, weights_row2);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels2, src20, weights_row0);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels2, src30, weights_row1);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels2, src40, weights_row2);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels3, src30, weights_row0);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels3, src40, weights_row1);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE1(pixels3, src50, weights_row2);
+
+#ifdef HAS_BIAS
+    Vector biases = CONVERT_TO_VECTOR_STRUCT_NO_STEP(biases);
+
+    float bias = *((__global float *)(vector_offset(&biases, get_global_id(2))));
+
+    pixels0 += (float2)bias;
+    pixels1 += (float2)bias;
+    pixels2 += (float2)bias;
+    pixels3 += (float2)bias;
+#endif /* defined(HAS_BIAS) */
+
+    vstore2(pixels0, 0, (__global float *)(dst.ptr + 0 * dst_stride_y));
+    vstore2(pixels1, 0, (__global float *)(dst.ptr + 1 * dst_stride_y));
+    vstore2(pixels2, 0, (__global float *)(dst.ptr + 2 * dst_stride_y));
+    vstore2(pixels3, 0, (__global float *)(dst.ptr + 3 * dst_stride_y));
+}
+
+/** This OpenCL kernel is optimized for Bifrost architectures and computes the depthwise convolution 3x3 when both
+ * stride_x and stride_y are equal to 2
+ *
+ * @param[in] src_ptr                               Pointer to the source image. Supported data types: F32
+ * @param[in] src_stride_x                          Stride of the source image 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 image 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_offset_first_element_in_bytes     The offset of the first element in the source image
+ * @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 Y processed per workitem(in bytes)
+ * @param[in] dst_ptr                               Pointer to the destination tensor. Supported data types: F32
+ * @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_stride_z                          Stride of the destination tensor in Z dimension (in bytes)
+ * @param[in] dst_step_z                            dst_stride_z * 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
+ * @param[in] weights_ptr                           Pointer to the weights tensor. Supported data types: F32
+ * @param[in] weights_stride_x                      Stride of the weights tensor in X dimension (in bytes)
+ * @param[in] weights_step_x                        weights_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in] weights_stride_y                      Stride of the weights tensor in Y dimension (in bytes)
+ * @param[in] weights_step_y                        weights_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in] weights_stride_z                      Stride of the weights tensor in Z dimension (in bytes)
+ * @param[in] weights_step_z                        weights_stride_z * number of elements along Y processed per workitem(in bytes)
+ * @param[in] weights_offset_first_element_in_bytes The offset of the first element in the biases vector
+ * @param[in] biases_ptr                            (Optional) Pointer to the biases vector. Supported data types: F32
+ * @param[in] biases_stride_x                       (Optional) Stride of the biases vector in X dimension (in bytes)
+ * @param[in] biases_step_x                         (Optional) biases_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in] biases_offset_first_element_in_bytes  (Optional) The offset of the first element in the biases vector
+ */
+__kernel void depthwise_convolution_3x3_stridex2_stridey2_bifrost(
+    TENSOR3D_DECLARATION(src),
+    TENSOR3D_DECLARATION(dst),
+    TENSOR3D_DECLARATION(weights)
+#if defined(HAS_BIAS)
+    ,
+    VECTOR_DECLARATION(biases)
+#endif //defined(HAS_BIAS)
+)
+{
+    Image    src     = CONVERT_TENSOR3D_TO_IMAGE_STRUCT(src);
+    Image    dst     = CONVERT_TENSOR3D_TO_IMAGE_STRUCT(dst);
+    Tensor3D weights = CONVERT_TO_TENSOR3D_STRUCT(weights);
+
+    float2 pixels0 = 0.0f;
+    float2 pixels1 = 0.0f;
+
+    __global uchar *weights_addr = (__global uchar *)weights.ptr;
+    __global uchar *src_addr     = (__global uchar *)offset(&src, 0, 0);
+
+    // Load the weights
+    float3 weights_row0 = vload3(0, (__global float *)(weights_addr + 0 * weights_stride_y));
+    float3 weights_row1 = vload3(0, (__global float *)(weights_addr + 1 * weights_stride_y));
+    float3 weights_row2 = vload3(0, (__global float *)(weights_addr + 2 * weights_stride_y));
+
+    // Note: Since each work-item computes 4x2 elements, we need to load 5 rows from the input tensor
+    float4 src00 = vload4(0, (__global float *)(src_addr + 0 * src_stride_y)); // Row0
+    float2 src01 = vload2(2, (__global float *)(src_addr + 0 * src_stride_y)); // Row0
+    float4 src10 = vload4(0, (__global float *)(src_addr + 1 * src_stride_y)); // Row1
+    float2 src11 = vload2(2, (__global float *)(src_addr + 1 * src_stride_y)); // Row1
+    float4 src20 = vload4(0, (__global float *)(src_addr + 2 * src_stride_y)); // Row2
+    float2 src21 = vload2(2, (__global float *)(src_addr + 2 * src_stride_y)); // Row2
+    float4 src30 = vload4(0, (__global float *)(src_addr + 3 * src_stride_y)); // Row3
+    float2 src31 = vload2(2, (__global float *)(src_addr + 3 * src_stride_y)); // Row3
+    float4 src40 = vload4(0, (__global float *)(src_addr + 4 * src_stride_y)); // Row4
+    float2 src41 = vload2(2, (__global float *)(src_addr + 4 * src_stride_y)); // Row4
+
+    CONVOLUTION1x3_BIFROST2X1_STRIDE2(pixels0, src00, src01, weights_row0);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE2(pixels0, src10, src11, weights_row1);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE2(pixels0, src20, src21, weights_row2);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE2(pixels1, src20, src21, weights_row0);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE2(pixels1, src30, src31, weights_row1);
+    CONVOLUTION1x3_BIFROST2X1_STRIDE2(pixels1, src40, src41, weights_row2);
+
+#ifdef HAS_BIAS
+    Vector biases = CONVERT_TO_VECTOR_STRUCT_NO_STEP(biases);
+
+    float bias = *((__global float *)(vector_offset(&biases, get_global_id(2))));
+
+    pixels0 += (float2)bias;
+    pixels1 += (float2)bias;
+#endif /* defined(HAS_BIAS) */
+
+    vstore2(pixels0, 0, (__global float *)(dst.ptr + 0 * dst_stride_y));
+    vstore2(pixels1, 0, (__global float *)(dst.ptr + 1 * dst_stride_y));
+}
+
 #if defined(SRC_WIDTH) && defined(DATA_TYPE)
 /** This kernel reshapes each of the tensor's low three dimensions to single rows.
  *
@@ -288,7 +492,6 @@ __kernel void depthwise_weights_reshape(
  * @param[in]  dst_step_z                        dst_stride_z * number of elements along Z 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 depthwise_im2col(TENSOR3D_DECLARATION(src), TENSOR3D_DECLARATION(dst))
 {
     Tensor3D dst = CONVERT_TO_TENSOR3D_STRUCT(dst);