From 81bf5d63e0b2f2c564c0726b1ee7a28b4c75c92e Mon Sep 17 00:00:00 2001
From: Ligeng Zhu <Lyken17@users.noreply.github.com>
Date: Fri, 20 Aug 2021 01:23:09 +0800
Subject: [PATCH] Update conv2d_transpose.py

---
 python/tvm/topi/nn/conv2d_transpose.py | 75 ++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/python/tvm/topi/nn/conv2d_transpose.py b/python/tvm/topi/nn/conv2d_transpose.py
index 22188bcd45a4..7f61b9bf30dc 100644
--- a/python/tvm/topi/nn/conv2d_transpose.py
+++ b/python/tvm/topi/nn/conv2d_transpose.py
@@ -116,6 +116,81 @@ def declaration_conv2d_transpose_impl(data, kernel, strides, padding, out_dtype,
     return Output
 
 
+def group_conv2d_transpose_nchw(data, kernel, stride=1, padding=0, output_padding=0, groups=1, dilation=1, out_dtype=None):
+    # some pre-processing and prelimnary checks 
+    if out_dtype is None:
+        out_dtype = data.dtype
+    
+    strides = _pair(stride)
+    padding = _pair(padding)
+    output_padding = _pair(output_padding)
+    dilation = _pair(dilation)
+    
+    batch, in_channels, in_height, in_width = get_const_tuple(data.shape)
+    _, out_c, filter_h, filter_w = kernel.shape
+    assert in_channels % groups == 0, "input channels must divide group size"
+    # assert out_c % groups == 0, "output channels must divide group size"
+    
+    batch, in_c, in_h, in_w = data.shape
+    _, out_c, filter_h, filter_w = kernel.shape
+    stride_h, stride_w = strides
+    opad_h, opad_w = output_padding
+    assert opad_h < stride_h and opad_w < stride_w
+    # dilate data
+    data_dilate = dilate(data, [1, 1, stride_h, stride_w], name="data_dilate")
+    # pad data
+    fpad_top, fpad_left, fpad_bottom, fpad_right = get_pad_tuple(padding, (filter_h, filter_w))
+    bpad_top = filter_h - 1 - fpad_top
+    bpad_bottom = filter_h - 1 - fpad_bottom + opad_h
+    bpad_left = filter_w - 1 - fpad_left
+    bpad_right = filter_w - 1 - fpad_right + opad_w
+    data_pad = pad(
+        data_dilate, [0, 0, bpad_top, bpad_left], [0, 0, bpad_bottom, bpad_right], name="data_pad"
+    )
+    # transform kernel layout from IOHW to OIHW, and rotate kernel by 180 degrees
+    kernel_transform = te.compute(
+        (out_c, in_c, filter_h, filter_w),
+        lambda i, o, h, w: kernel[o][i][filter_h - 1 - h][filter_w - 1 - w],
+        name="kernel_transform",
+    )
+    
+    batch, in_c, in_h, in_w = data_pad.shape
+    out_c, _, filter_h, filter_w = kernel_transform.shape
+
+    # convolution stage
+    out_c = simplify(out_c)
+    out_channels = simplify(out_c * groups)
+
+    out_h = simplify(in_h - filter_h + 1)
+    out_w = simplify(in_w - filter_w + 1)
+    dc = te.reduce_axis((0, in_c // groups), name="dc")
+    dh = te.reduce_axis((0, filter_h), name="dh")
+    dw = te.reduce_axis((0, filter_w), name="dw")
+    
+    # data: batch, in_channels, out_h, out_w
+    # weight: out_channels // G, in_channels, out_h, out_w
+    return te.compute(
+        (batch, out_channels, out_h, out_w),
+        lambda b, c, h, w: te.sum(
+            data_pad[
+                b, 
+                c // (out_channels // groups) * (in_channels // groups) + dc, 
+                h + dh, 
+                w + dw
+            ].astype(out_dtype)
+            * kernel_transform[
+                c % (out_channels // groups), 
+                c // (out_channels // groups) * (in_channels // groups) + dc, 
+                dh, 
+                dw
+            ].astype(out_dtype),
+            axis=[dc, dh, dw],
+        ),
+        tag="conv2d_transpose_nchw",
+    )
+
+
+
 @tvm.target.generic_func
 def conv2d_transpose_legalize(attrs, inputs, types):
     """Legalizes Transposed 2D convolution op.