[QNN] Concat - Refactoring to C++ (apache#3819)

include/tvm/relay/qnn/attrs.h

@@ -88,7 +88,7 @@ struct DequantizeAttrs : public tvm::AttrsNode<DequantizeAttrs> {
   int32_t input_zero_point;
   double input_scale;
 
-  TVM_DECLARE_ATTRS(QuantizeAttrs, "relay.attrs.QuantizeAttrs") {
+  TVM_DECLARE_ATTRS(DequantizeAttrs, "relay.attrs.DequantizeAttrs") {
     TVM_ATTR_FIELD(input_zero_point)
       .describe("The zero_point for the input tensor of this op.");
 
@@ -97,6 +97,34 @@ struct DequantizeAttrs : public tvm::AttrsNode<DequantizeAttrs> {
   }
 };
 
+/*! \brief Attributes used in QNN concatenate operator */
+struct QnnConcatenateAttrs : public tvm::AttrsNode<QnnConcatenateAttrs> {
+  Array<tvm::Expr> input_scales;
+  Array<tvm::Expr> input_zero_points;
+  double output_scale;
+  int32_t output_zero_point;
+  int axis;
+
+  TVM_DECLARE_ATTRS(QnnConcatenateAttrs, "relay.attrs.QnnConcatenateAttrs") {
+    TVM_ATTR_FIELD(input_scales)
+        .describe("The list of scales of input quantized tensors.");
+
+    TVM_ATTR_FIELD(input_zero_points)
+        .describe("The list of zero points of input quantized tensors.");
+
+    TVM_ATTR_FIELD(output_zero_point)
+      .describe("The zero_point for the output tensor.");
+
+    TVM_ATTR_FIELD(output_scale)
+      .describe("The scale for the output tensor.");
+
+    TVM_ATTR_FIELD(axis)
+        .describe("The axis at which the input arrays are concatenated."
+                  "Should lie in range `[-ndim, ndim)`.")
+        .set_default(0);
+  }
+};  // struct QnnConcatenateAttrs
+
 }  // namespace qnn
 }  // namespace relay
 }  // namespace tvm

python/tvm/relay/qnn/op/qnn.py

@@ -18,7 +18,8 @@
 """QNN dialect operators."""
 
 from __future__ import absolute_import as _abs
-from tvm import relay
+from tvm.expr import FloatImm, IntImm
+from tvm.relay.expr import Tuple
 from . import _make
 
 def requantize(data,
@@ -134,6 +135,8 @@ def dequantize(data,
     return _make.dequantize(data,
                             input_scale,
                             input_zero_point)
+
+
 def concatenate(data,
                 input_scales,
                 input_zero_points,
@@ -169,42 +172,14 @@ def concatenate(data,
     """
 
     data = list(data)
-    requantized_exprs = list(data)
-
-    # Find the dtype of the input expr. This is required for the requantize op. Since, this is
-    # concatenate op, the dtype of the input is same as dtype of the output.
-    mod = relay.Module.from_expr(data[0])
-    mod = relay.transform.InferType()(mod)
-    entry = mod["main"]
-    data0 = entry if isinstance(data[0], relay.Function) else entry.body
-    in_dtype = data0.checked_type.dtype
-
-    # First check if all the input qnn params match. If yes, we can call concatenate first, followed
-    # by a requantize.
-    if all(scale == input_scales[0] for scale in input_scales)\
-            and all(zero_point == input_zero_points[0] for zero_point in input_zero_points):
-        out = relay.concatenate(tuple(data), axis)
-        input_scale = input_scales[0]
-        input_zero_point = input_zero_points[0]
-        if input_scale != output_scale or input_zero_point != output_zero_point:
-            out = requantize(data=out,
-                             input_scale=input_scales[0],
-                             input_zero_point=input_zero_points[0],
-                             output_scale=output_scale,
-                             output_zero_point=output_zero_point,
-                             out_dtype=in_dtype)
-        return out
-
-    # If the output qnn params do not match the input qnn params, we can call requantize on the
-    # input expr first, followed by a concatenate on the requantized input exprs.
-    for idx, quantized_expr in enumerate(data):
-        input_scale = input_scales[idx]
-        input_zero_point = input_zero_points[idx]
-        if input_scale != output_scale or input_zero_point != output_zero_point:
-            requantized_exprs[idx] = requantize(data=quantized_expr,
-                                                input_scale=input_scale,
-                                                input_zero_point=input_zero_point,
-                                                output_scale=output_scale,
-                                                output_zero_point=output_zero_point,
-                                                out_dtype=in_dtype)
-    return relay.concatenate(tuple(requantized_exprs), axis)
+    if not data:
+        raise ValueError("relay.concatenate requires data to be non-empty.")
+    if not isinstance(axis, int):
+        raise ValueError("For now, we only support integer axis")
+
+    return _make.concatenate(Tuple(data),
+                             [FloatImm("float64", x) for x in input_scales],
+                             [IntImm("int32", x) for x in input_zero_points],
+                             output_scale,
+                             output_zero_point,
+                             axis)

src/relay/qnn/op/concatenate.cc

@@ -0,0 +1,134 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*!
+ *  Copyright (c) 2019 by Contributors
+ * \file src/relay/qnn/op/concatenate.cc
+ * \brief QNN concatenate operator. It concatenates quantized input tensors along a given axis.
+ */
+
+#include <tvm/ir.h>
+#include <tvm/relay/analysis.h>
+#include <tvm/relay/op_attr_types.h>
+#include <tvm/relay/qnn/attrs.h>
+#include "../../op/tensor/transform.h"
+#include "../../pass/pattern_util.h"
+#include "../util.h"
+
+namespace tvm {
+namespace relay {
+namespace qnn {
+
+TVM_REGISTER_NODE_TYPE(QnnConcatenateAttrs);
+
+Expr MakeQnnConcatenate(Expr data, Array<tvm::Expr> input_scales,
+                        Array<tvm::Expr> input_zero_points, double output_scale,
+                        int32_t output_zero_point, int axis) {
+  auto attrs = make_node<QnnConcatenateAttrs>();
+  attrs->input_scales = std::move(input_scales);
+  attrs->input_zero_points = std::move(input_zero_points);
+  attrs->output_scale = output_scale;
+  attrs->output_zero_point = output_zero_point;
+  attrs->axis = axis;
+  static const Op& op = Op::Get("qnn.concatenate");
+  return CallNode::make(op, {data}, Attrs(attrs), {});
+}
+
+/*
+ * \brief Canonicalizes the QNN concatenate op.
+ * \param attrs The QNN concatenate attrs.
+ * \param new_args The new mutated args to the call node.
+ * \param arg_types The types of input and output.
+ * \return The sequence of Relay ops for concatenate op.
+ */
+Expr ConcatenateQnnCanonicalize(const Attrs& attrs, const Array<Expr>& new_args,
+                                const Array<tvm::relay::Type>& arg_types) {
+  // Get the attrs.
+  CHECK_EQ(new_args.size(), 1);
+  auto& data = new_args[0];
+  const auto* concatenate_attrs = attrs.as<QnnConcatenateAttrs>();
+  CHECK(concatenate_attrs != nullptr);
+  auto input_scales = concatenate_attrs->input_scales;
+  auto input_zero_points = concatenate_attrs->input_zero_points;
+  auto output_scale = concatenate_attrs->output_scale;
+  auto output_zero_point = concatenate_attrs->output_zero_point;
+
+  // Get the input dtype and shape.
+  CHECK_GE(arg_types.size(), 1);
+  auto tuple_type = arg_types[0].as<TupleTypeNode>();
+  CHECK(tuple_type != nullptr);
+
+  // FIXME (anijain2305) - The lowering can be further optimized. Instead of inserting requantize in
+  // the start, we can insert requantize at the end if and only if all the input tensors have same
+  // qnn params. This can be done in future.
+
+  // If the output qnn params do not match the input qnn params, we can call requantize on the input
+  // expr first, followed by a concatenate on the requantized input exprs.
+
+  auto tuple_data = data.as<TupleNode>();
+  CHECK(tuple_data != nullptr);
+
+  int idx = 0;
+  Array<Expr> requantized_exprs;
+  for (auto quantized_expr : tuple_data->fields) {
+    // Get the input scale for the idx quantized input tensor.
+    auto input_scale_expr = input_scales[idx].as<tvm::ir::FloatImm>();
+    CHECK(input_scale_expr != nullptr);
+    auto input_scale = input_scale_expr->value;
+
+    // Get the zero point for the idx quantized input tensor.
+    auto input_zero_point_expr = input_zero_points[idx].as<tvm::ir::IntImm>();
+    CHECK(input_zero_point_expr != nullptr);
+    auto input_zero_point = input_zero_point_expr->value;
+
+    // Check if output and input qnn params are same. If not, requantize.
+    if (input_scale != output_scale || input_zero_point != output_zero_point) {
+      // Get the input shape and dtype.
+      auto tensor_type = tuple_type->fields[idx].as<TensorTypeNode>();
+      auto input_dtype = tensor_type->dtype;
+      auto input_shape = tensor_type->shape;
+
+      // Requantize the input.
+      auto requantized_expr = Requantize(quantized_expr, input_shape, input_scale, input_zero_point,
+                                         output_scale, output_zero_point, input_dtype);
+      requantized_exprs.push_back(requantized_expr);
+    } else {
+      requantized_exprs.push_back(quantized_expr);
+    }
+    idx++;
+  }
+  return MakeConcatenate(TupleNode::make(requantized_exprs), concatenate_attrs->axis);
+}
+
+RELAY_REGISTER_OP("qnn.concatenate")
+.describe(R"code(Concatenate the quantized input tensors along the given axis.
+)code" TVM_ADD_FILELINE)
+.set_attrs_type_key("relay.attrs.QnnConcatenateAttrs")
+.set_num_inputs(1)
+.add_argument("data", "Tensor", "The tensor to concatenate.")
+.set_support_level(11)
+.add_type_rel("QnnConcatenate", ConcatenateRel<QnnConcatenateAttrs>)
+.set_attr<FTVMLegalize>("FTVMQnnCanonicalize", ConcatenateQnnCanonicalize);
+
+TVM_REGISTER_API("relay.qnn.op._make.concatenate")
+.set_body_typed(MakeQnnConcatenate);
+
+}  // namespace qnn
+}  // namespace relay
+}  // namespace tvm

src/relay/qnn/util.h

@@ -28,6 +28,8 @@
 #include <tvm/expr.h>
 #include <tvm/relay/expr.h>
 #include <limits>
+#include <string>
+#include <utility>
 
 namespace tvm {
 namespace relay {
@@ -67,6 +69,23 @@ static inline const int32_t GetQmax(const DataType& dtype) {
   }
 }
 
+Expr RequantizeLower(const Expr& input_tensor, const RequantizeAttrs* param,
+                     const Array<IndexExpr>& input_shape, const DataType& out_dtype);
+
+static inline Expr Requantize(const Expr& data, const Array<IndexExpr>& input_shape,
+                              double input_scale, int32_t input_zero_point, double output_scale,
+                              int32_t output_zero_point, const DataType& out_dtype,
+                              const std::string& rounding = "TONEAREST") {
+  auto attrs = make_node<RequantizeAttrs>();
+  attrs->input_scale = std::move(input_scale);
+  attrs->input_zero_point = std::move(input_zero_point);
+  attrs->output_scale = std::move(output_scale);
+  attrs->output_zero_point = std::move(output_zero_point);
+  attrs->rounding = std::move(rounding);
+  attrs->out_dtype = std::move(out_dtype);
+  return RequantizeLower(data, attrs.operator->(), input_shape, out_dtype);
+}
+
 }  // namespace qnn
 }  // namespace relay
 }  // namespace tvm

tests/python/relay/test_qnn_concatenate.py

@@ -39,7 +39,6 @@ def test_same_io_qnn_params():
                                  axis=axis)
 
     func = relay.Function([x, y], z)
-    assert func.astext().count('requantize') == 0
     mod = relay.Module.from_expr(func)
     mod = relay.qnn.transform.CanonicalizeOps()(mod)
     func = mod["main"]
@@ -68,7 +67,6 @@ def test_different_io_qnn_params():
                                  axis=axis)
 
     func = relay.Function([x, y], z)
-    assert func.astext().count('requantize') == 2
     mod = relay.Module.from_expr(func)
     mod = relay.qnn.transform.CanonicalizeOps()(mod)
     func = mod["main"]
@@ -97,7 +95,6 @@ def test_few_same_io_qnn_params():
                                  axis=axis)
 
     func = relay.Function([x, y], z)
-    assert func.astext().count('requantize') == 1
     mod = relay.Module.from_expr(func)
     mod = relay.qnn.transform.CanonicalizeOps()(mod)
     func = mod["main"]
@@ -126,7 +123,6 @@ def test_same_i_qnn_params():
                                  axis=axis)
 
     func = relay.Function([x, y], z)
-    assert func.astext().count('requantize') == 1
     mod = relay.Module.from_expr(func)
     mod = relay.qnn.transform.CanonicalizeOps()(mod)
     func = mod["main"]