Implemented convolution as im2col + GEMM

1 files changed, 41 insertions, 1 deletions

diff --git a/src/routines/levelx/xconvgemm.cpp b/src/routines/levelx/xconvgemm.cpp
index 2676dbda..0e59b5be 100644
--- a/src/routines/levelx/xconvgemm.cpp
+++ b/src/routines/levelx/xconvgemm.cpp
@@ -12,6 +12,8 @@
 // =================================================================================================
 
 #include "routines/levelx/xconvgemm.hpp"
+#include "routines/levelx/xim2col.hpp"
+#include "routines/level3/xgemm.hpp"
 
 #include <string>
 #include <vector>
@@ -52,7 +54,45 @@ void Xconvgemm<T>::DoConvgemm(const size_t channels, const size_t height, const
   const auto padding_w = dilation_w * (kernel_w - 1) + 1;
   const auto output_w = (size_w >= padding_w) ? (size_w - padding_w) / stride_w + 1 : 1;
 
-  throw BLASError(StatusCode::kNotImplemented);
+  // Temporary col matrix
+  const auto patch_size = kernel_h * kernel_w * channels;
+  const auto num_patches = output_h * output_w;
+  const auto col_size = patch_size * num_patches;
+  auto col_buffer = Buffer<T>(context_, col_size);
+
+  // Approach: im2col + GEMM
+  //      result = GEMM(im2col(image), kernel)
+  for (auto batch_id = size_t{0}; batch_id < batch_count; ++batch_id) {
+
+    // im2col
+    const auto im_batch_offset = batch_id * channels * height * width + im_offset;
+    auto im2col_event = Event();
+    auto im2col = Xim2col<T>(queue_, im2col_event.pointer());
+    im2col.DoIm2col(channels, height, width, kernel_h, kernel_w,
+                    pad_h, pad_w, stride_h, stride_w, dilation_h, dilation_w,
+                    im_buffer, im_batch_offset,
+                    col_buffer, 0);
+    im2col_event.WaitForCompletion();
+
+    // GEMM: C (result) = alpha (1) * A (col) * B (kernel) + beta (0) * C (result)
+    const auto m = num_patches;
+    const auto n = num_kernels;
+    const auto k = patch_size;
+    const auto col_gemm_offset = size_t{0}; // A
+    const auto kernel_gemm_offset = kernel_offset; // B
+    const auto result_gemm_offset = batch_id * num_kernels * output_h * output_w + result_offset; // C
+    const auto col_ld = m;
+    const auto kernel_ld = k;
+    const auto result_ld = m;
+    auto gemm_event = Event();
+    auto gemm = Xgemm<T>(queue_, gemm_event.pointer());
+    gemm.DoGemm(Layout::kColMajor, Transpose::kNo, Transpose::kNo,
+                m, n, k, ConstantOne<T>(),
+                col_buffer, col_gemm_offset, col_ld,
+                kernel_buffer, kernel_gemm_offset, kernel_ld, ConstantZero<T>(),
+                result_buffer, result_gemm_offset, result_ld);
+    gemm_event.WaitForCompletion();
+  }
 }
 
 // =================================================================================================