From ff6ac445291edfa8db8faaaa5d73615952fe6037 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=A2=85=ED=98=84/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Staff=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <jh1302.park@samsung.com>
Date: Thu, 30 Aug 2018 17:33:57 +0900
Subject: [PATCH] [enco] Convolution Shape inference with stride (#1251)

This commit revises ConvolutionSpec to infer stride values for each
spatial axis, and use these values for OFM shape inference.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
---
 .../enco/frontend/caffe/src/ConvolutionSpec.cpp    | 30 +++++++++---
 contrib/enco/frontend/caffe/src/ConvolutionSpec.h  |  1 +
 .../frontend/caffe/src/ConvolutionSpec.test.cpp    | 55 ++++++++++++++++++++++
 3 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/contrib/enco/frontend/caffe/src/ConvolutionSpec.cpp b/contrib/enco/frontend/caffe/src/ConvolutionSpec.cpp
index bc691f0..345a499 100644
--- a/contrib/enco/frontend/caffe/src/ConvolutionSpec.cpp
+++ b/contrib/enco/frontend/caffe/src/ConvolutionSpec.cpp
@@ -11,12 +11,6 @@ ConvolutionSpec::ConvolutionSpec(const ::caffe::ConvolutionParameter &param)
   assert(param.pad_h() == 0);
   assert(param.pad_w() == 0);
 
-  // NOTE Stride is not supported, yet
-  // TODO Support padding
-  assert(param.stride().size() == 0);
-  assert(!param.has_stride_h());
-  assert(!param.has_stride_w());
-
   // NOTE Dilation is not supported, yet
   // TODO Support dilation
   assert(param.dilation().size() == 0);
@@ -39,6 +33,29 @@ uint32_t ConvolutionSpec::channel_axis(void) const
   return ifm_rank() + axis;
 }
 
+uint32_t ConvolutionSpec::stride(uint32_t spatial_axis) const
+{
+  assert(spatial_axis < num_spatial_axes());
+
+  // TODO Support stride_h/stride_w parameters
+  assert(!_param.has_stride_h());
+  assert(!_param.has_stride_w());
+
+  if (_param.stride().size() == 0)
+  {
+    // NOTE default stride is 1
+    return 1;
+  }
+
+  if (_param.stride().size() == 1)
+  {
+    return _param.stride(0);
+  }
+
+  assert(_param.stride().size() == num_spatial_axes());
+  return _param.stride(spatial_axis);
+}
+
 uint32_t ConvolutionSpec::ker_dim(uint32_t spatial_axis) const
 {
   assert(spatial_axis < num_spatial_axes());
@@ -96,6 +113,7 @@ nncc::core::ADT::tensor::Shape ConvolutionSpec::ofm_shape(void) const
     uint32_t dim = 0;
 
     dim += ifm_dim(full_axis) - ker_dim(spatial_axis);
+    dim /= stride(spatial_axis);
     dim += 1;
 
     res.dim(full_axis) = dim;
diff --git a/contrib/enco/frontend/caffe/src/ConvolutionSpec.h b/contrib/enco/frontend/caffe/src/ConvolutionSpec.h
index 64b6688..6c6e288 100644
--- a/contrib/enco/frontend/caffe/src/ConvolutionSpec.h
+++ b/contrib/enco/frontend/caffe/src/ConvolutionSpec.h
@@ -19,6 +19,7 @@ public:
   uint32_t num_batch_axes(void) const { return channel_axis(); }
   uint32_t num_spatial_axes(void) const { return ifm_rank() - channel_axis() - 1; }
 
+  uint32_t stride(uint32_t spatial_axis) const;
   uint32_t ker_dim(uint32_t spatial_axis) const;
 
 public:
diff --git a/contrib/enco/frontend/caffe/src/ConvolutionSpec.test.cpp b/contrib/enco/frontend/caffe/src/ConvolutionSpec.test.cpp
index 354b5ea..4870a52 100644
--- a/contrib/enco/frontend/caffe/src/ConvolutionSpec.test.cpp
+++ b/contrib/enco/frontend/caffe/src/ConvolutionSpec.test.cpp
@@ -171,3 +171,58 @@ TEST_F(ConvolutionSpecTest, conv_1)
     ASSERT_EQ(expected, obtained);
   }
 }
+
+namespace
+{
+// NOTE This example is derived from conv1_3x3_s2 layer in reference inception v3 layer
+// clang-format off
+const char *conv_2 = STRING(
+layer {
+  name: "data"
+  type: "Input"
+  top: "data"
+  input_param {
+    shape: { dim: 1 dim: 3 dim: 299 dim: 299 }
+  }
+}
+layer {
+  name: "conv"
+  type: "Convolution"
+  bottom: "data"
+  top: "conv"
+  convolution_param {
+    bias_term: false
+    num_output: 2
+    stride: 2
+    kernel_size: 3
+  }
+}
+);
+// clang-format on
+} // namespace
+
+TEST_F(ConvolutionSpecTest, conv_2)
+{
+  ::caffe::NetParameter param;
+
+  ASSERT_TRUE(load(conv_2, param));
+
+  ::caffe::Net<float> net{param};
+
+  const tensor::Shape ifm_shape{1, 3, 299, 299};
+  ConvolutionSpec spec{param.layer(1).convolution_param()};
+
+  spec.ifm_shape(ifm_shape);
+
+  // Check 'stride'
+  ASSERT_EQ(spec.stride(0), 2);
+  ASSERT_EQ(spec.stride(1), 2);
+
+  // Check 'ofm_shape'
+  {
+    auto expected = as_tensor_shape(net.blob_by_name("conv")->shape());
+    auto obtained = spec.ofm_shape();
+
+    ASSERT_EQ(expected, obtained);
+  }
+}
-- 
2.7.4