[QNN] Lowering for Depthwise Convolution. (#4351)

src/relay/pass/pattern_util.h

@@ -503,6 +503,8 @@ static inline Expr Tile(Expr data, Array<Integer> reps) {
 
 Expr MakeConcatenate(Expr data, int axis);
 
+Expr MakeRepeat(Expr data, int repeats, int axis);
+
 Expr MakeStridedSlice(Expr data, Array<Integer> begin, Array<Integer> end, Array<Integer> strides);
 
 Expr MakeStack(Expr data, int axis);

topi/python/topi/x86/conv2d_alter_op.py

@@ -197,6 +197,11 @@ def _conv2d_legalize(attrs, inputs, arg_types):
     if not (dilation[0] == 1 and dilation[1] == 1):
         return None
 
+    # No legalization for depthwise convolutions yet.
+    groups = attrs.get_int("groups")
+    if groups != 1:
+        return None
+
     # Collect the input tensors.
     data_tensor, kernel_tensor = arg_types[0], arg_types[1]
     data_dtype = data_tensor.dtype