add Concat quantization (#17448)

* add Concat quantization
add unit test for quantizing concat
fix for wrong value when the input is not in map of calculated scales
add use_quantizer to concat_op.cc
add scale_algo rules for concat

test=develop

* missing fix for multiple inputs quantize-squash

* wojtuss review fix: adding comment

test=develop

paddle/fluid/framework/ir/graph_pattern_detector.cc

@@ -1214,6 +1214,17 @@ PDNode *patterns::ElementwiseAdd::operator()(PDNode *x_var, PDNode *y_var) {
   return out_var;
 }
 
+PDNode *patterns::Concat::operator()() {
+  auto concat_op = pattern->NewNode(concat_op_repr())->assert_is_op("concat");
+
+  auto output_var = pattern->NewNode(concat_out_repr())
+                        ->AsOutput()
+                        ->assert_is_op_output("concat", "Out");
+
+  concat_op->LinksTo({output_var});
+  return output_var;
+}
+
 PDNode *patterns::ConcatReLU::operator()() {
   auto concat_op = pattern->NewNode(concat_op_repr())->assert_is_op("concat");
   auto relu_op = pattern->NewNode(relu_op_repr())->assert_is_op("relu");

paddle/fluid/framework/ir/graph_pattern_detector.h

@@ -747,6 +747,19 @@ struct ElementwiseAdd : public PatternBase {
   PATTERN_DECL_NODE(elementwise_add_out);
 };
 
+// Concat op
+// Forward pass for concat.
+// concat_out is a result of the operator.
+struct Concat : public PatternBase {
+  Concat(PDPattern* pattern, const std::string& name_scope)
+      : PatternBase(pattern, name_scope, "concat") {}
+
+  PDNode* operator()();
+
+  PATTERN_DECL_NODE(concat_op);
+  PATTERN_DECL_NODE(concat_out);
+};
+
 // Concat + ReLU
 // named nodes:
 // concat_op, concat_out, relu_op, relu_out

paddle/fluid/framework/ir/mkldnn/cpu_quantize_pass.cc

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "paddle/fluid/framework/ir/mkldnn/cpu_quantize_pass.h"
+#include <limits>
 #include <utility>
 #include <vector>
 #include "paddle/fluid/framework/eigen.h"
@@ -72,6 +73,53 @@ void CPUQuantizePass::QuantizeInput(Graph* g, Node* op, Node* input,
   if (!scale_attr_name.empty()) op->Op()->SetAttr(scale_attr_name, scale);
 }
 
+void CPUQuantizePass::QuantizeInputs(Graph* g, Node* op, std::string input_name,
+                                     VarQuantScale* scales, bool are_unsigned,
+                                     std::string scale_attr_name) const {
+  auto inputs = op->inputs;
+  PADDLE_ENFORCE_GE(inputs.size(), 1);
+
+  // create a quantize op desc prototype
+  OpDesc q_desc;
+  q_desc.SetType("quantize");
+
+  std::vector<Node*> quantize_out_nodes(inputs.size());
+  std::vector<std::string> quantize_out_node_names(inputs.size());
+
+  double scale_min = std::numeric_limits<double>::max();
+  for (const auto& input : inputs) {
+    double scale = (*scales)[input->Name()].second.data<double>()[0];
+    if (scale < scale_min) scale_min = scale;
+  }
+  unsigned max = are_unsigned ? U8_MAX : S8_MAX;
+  float scale = scale_min * max;
+
+  for (size_t i = 0; i < inputs.size(); i++) {
+    // Create quantize output variable
+    VarDesc quantize_out_desc(patterns::PDNodeName("quantize", "out"));
+    quantize_out_nodes[i] = g->CreateVarNode(&quantize_out_desc);
+    quantize_out_node_names[i] = quantize_out_nodes[i]->Name();
+
+    q_desc.SetAttr("Scale", scale);
+    q_desc.SetInput("Input", std::vector<std::string>({inputs[i]->Name()}));
+    q_desc.SetOutput("Output",
+                     std::vector<std::string>({quantize_out_node_names[i]}));
+    q_desc.SetAttr("is_negative_input", !are_unsigned);
+    auto quantize_op = g->CreateOpNode(&q_desc);  // OpDesc will be copied.
+
+    // link quantize op
+    UnlinkNodes(inputs[i], op);
+    IR_NODE_LINK_TO(inputs[i], quantize_op);
+    IR_NODE_LINK_TO(quantize_op, quantize_out_nodes[i]);
+    IR_NODE_LINK_TO(quantize_out_nodes[i], op);
+  }
+
+  // update op's input
+  op->Op()->SetInput(input_name, quantize_out_node_names);
+
+  if (!scale_attr_name.empty()) op->Op()->SetAttr(scale_attr_name, scale);
+}
+
 void CPUQuantizePass::DequantizeOutput(Graph* g, Node* op, Node* output,
                                        std::string output_name,
                                        double scale_to_one, bool is_unsigned,
@@ -216,6 +264,48 @@ void CPUQuantizePass::QuantizePool(Graph* graph) const {
   PrettyLogDetail("---    quantized %d pool2d ops", quantize_pool_count);
 }
 
+void CPUQuantizePass::QuantizeConcat(Graph* graph) const {
+  GraphPatternDetector gpd;
+  auto pattern = gpd.mutable_pattern();
+  patterns::Concat concat_pattern{pattern, name_scope_};
+  concat_pattern();
+
+  int quantize_concat_count = 0;
+  auto handler = [&](const GraphPatternDetector::subgraph_t& subgraph,
+                     Graph* g) {
+    VLOG(4) << "Quantize concat op";
+    GET_IR_NODE_FROM_SUBGRAPH(concat_op, concat_op, concat_pattern);
+    auto* concat_op_desc = concat_op->Op();
+
+    // skip if should not be quantized
+    if (!concat_op_desc->HasAttr("use_quantizer") ||
+        !boost::get<bool>(concat_op_desc->GetAttr("use_quantizer")))
+      return;
+
+    GET_IR_NODE_FROM_SUBGRAPH(concat_out, concat_out, concat_pattern);
+
+    // get scales calculated after warmup, they scale variables to MAX=1.0
+    auto scales = Get<VarQuantScale>("quant_var_scales");
+
+    // if all inputs were unsigned, then the output was set to unsigned
+    // during the scale calculation step
+    bool are_all_inputs_unsigned = scales[concat_out->Name()].first;
+    QuantizeInputs(g, concat_op, "X", &scales, are_all_inputs_unsigned);
+
+    auto output_scale = scales[concat_out->Name()].second.data<double>()[0];
+
+    DequantizeOutput(g, concat_op, concat_out, "Out", output_scale,
+                     are_all_inputs_unsigned);
+
+    ++quantize_concat_count;
+  };
+
+  gpd(graph, handler);
+  AddStatis(quantize_concat_count);
+
+  PrettyLogDetail("---    quantized %d concat ops", quantize_concat_count);
+}
+
 void CPUQuantizePass::ApplyImpl(ir::Graph* graph) const {
   VLOG(3) << "Quantizing the graph.";
   PADDLE_ENFORCE(graph);
@@ -226,6 +316,7 @@ void CPUQuantizePass::ApplyImpl(ir::Graph* graph) const {
   QuantizeConv(graph, false /* with_residual_data */);
   QuantizeConv(graph, true /* with_residual_data */);
   QuantizePool(graph);
+  QuantizeConcat(graph);
 }
 
 }  // namespace ir

paddle/fluid/framework/ir/mkldnn/cpu_quantize_pass.h

@@ -48,10 +48,17 @@ class CPUQuantizePass : public FusePassBase {
 
   void QuantizePool(Graph* graph) const;
 
+  void QuantizeConcat(Graph* graph) const;
+
   void QuantizeInput(Graph* g, Node* op, Node* input, std::string input_name,
                      double scale_to_one, bool is_unsigned,
                      std::string scale_attr_name = "") const;
 
+  // quantize all inputs of given name with the same (minimum) scale
+  void QuantizeInputs(Graph* g, Node* op, std::string input_name,
+                      VarQuantScale* scales, bool are_unsigned,
+                      std::string scale_attr_name = "") const;
+
   void DequantizeOutput(Graph* g, Node* op, Node* output,
                         std::string output_name, double scale_to_one,
                         bool is_unsigned,

paddle/fluid/framework/ir/mkldnn/cpu_quantize_pass_tester.cc

@@ -60,9 +60,14 @@ void SetOp(ProgramDesc* prog, const std::string& type, const std::string& name,
     if (inputs.size() > 1) op->SetInput("W", {inputs[1]});
     if (inputs.size() > 2) op->SetInput("Bias", {inputs[2]});
     op->SetOutput("Out", {outputs[0]});
+  } else if (type == "concat") {
+    op->SetInput("X", inputs);
+    op->SetOutput("Out", outputs);
+    op->SetAttr("use_quantizer", use_quantizer);
   }
 }
 
+namespace {
 static const std::initializer_list<std::string> variable_names{
     "a", "w1", "c",  "d", "w2", "e",  "f", "g",
     "h", "w3", "b1", "i", "j",  "w4", "b2"};
@@ -204,6 +209,101 @@ TEST(CpuQuantizePass, do_not_quantize) {
            1.0f);
 }
 
+}  // namespace
+
+namespace {
+static const std::initializer_list<std::string> variable_names_concat = {
+    "a1", "b1", "a2", "b2", "c", "d"};
+
+// a1->Pool1->b1
+// a2->Pool2->b2
+// (b1,b2)->Concat->c
+// c->Pool3->d
+ProgramDesc BuildProgramDescConcat() {
+  ProgramDesc prog;
+
+  SetOp(&prog, "pool2d", "Pool1", {"a1"}, {"b1"}, true, false);
+  SetOp(&prog, "pool2d", "Pool2", {"a2"}, {"b2"}, true, false);
+  SetOp(&prog, "concat", "Concat", {"b1", "b2"}, {"c"}, true, true);
+  SetOp(&prog, "pool2d", "Pool3", {"c"}, {"d"}, true, false);
+
+  return prog;
+}
+
+void MainTestConcat(const ProgramDesc& prog, int pool_count, int concat_count,
+                    int quant_count, int dequant_count, int added_nodes_count) {
+  std::unique_ptr<ir::Graph> graph(new ir::Graph(prog));
+
+  // Init scope, as it is used in pass
+  auto place = paddle::platform::CPUPlace();
+  NaiveExecutor exe{place};
+  Scope scope;
+  exe.CreateVariables(prog, 0, true, &scope);
+
+  auto* scales = new VarQuantScale();
+
+  for (auto& v : variable_names_concat) {
+    InitTensorHolder(&scope, place, v.c_str());
+    LoDTensor tensor;
+    tensor.Resize({1});
+    auto* ptr = tensor.mutable_data<double>(place);
+    ptr[0] = 2.0;
+
+    (*scales)[v] = std::make_pair(false, std::move(tensor));
+  }
+
+  graph->SetNotOwned(kParamScopeAttr, &scope);
+
+  auto pass = PassRegistry::Instance().Get("cpu_quantize_pass");
+  pass->Set("quant_var_scales", scales);
+
+  int original_nodes_num = graph->Nodes().size();
+
+  graph.reset(pass->Apply(graph.release()));
+
+  int current_nodes_num = graph->Nodes().size();
+
+  int quantize_nodes_count = 0;
+  int dequantize_nodes_count = 0;
+  int concat_nodes_count = 0;
+  int pool2d_nodes_count = 0;
+  for (auto* node : graph->Nodes()) {
+    if (node->IsOp()) {
+      auto* op = node->Op();
+      if (op->Type() == "concat") {
+        concat_nodes_count++;
+      } else if (op->Type() == "pool2d") {
+        pool2d_nodes_count++;
+      } else if (op->Type() == "quantize") {
+        quantize_nodes_count++;
+      } else if (op->Type() == "dequantize") {
+        dequantize_nodes_count++;
+      }
+    }
+  }
+  EXPECT_EQ(concat_nodes_count, concat_count);
+  EXPECT_EQ(pool2d_nodes_count, pool_count);
+  EXPECT_EQ(quantize_nodes_count, quant_count);
+  EXPECT_EQ(dequantize_nodes_count, dequant_count);
+  EXPECT_EQ(original_nodes_num + added_nodes_count, current_nodes_num);
+}
+
+TEST(CpuQuantizePass, concat) {
+  // a1->Pool1->b1
+  // a2->Pool2->b2
+  // (b1->QUANT1->IN1, b2->QUANT2->IN2)->Concat->c
+  // c->OUT1->DEQUANT1->Pool3->d
+  int pool_count = 3;
+  int concat_count = 1;
+  int quant_count = 2;
+  int dequant_count = 1;
+  int added_nodes_count = 6;
+  MainTestConcat(BuildProgramDescConcat(), pool_count, concat_count,
+                 quant_count, dequant_count, added_nodes_count);
+}
+
+}  // namespace
+
 }  // namespace ir
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/framework/ir/mkldnn/cpu_quantize_squash_pass.cc

@@ -14,6 +14,7 @@
 // limitations under the License.
 
 #include "paddle/fluid/framework/ir/mkldnn/cpu_quantize_squash_pass.h"
+#include <algorithm>
 #include <string>
 #include <vector>
 #include "paddle/fluid/platform/enforce.h"
@@ -81,15 +82,10 @@ void CPUQuantizeSquashPass::Squash(
       auto quant_out_var_name = quant_out->Name();
       auto next_op_inputs = next_op_desc->InputNames();
       for (const auto& name : next_op_inputs) {
-        if (next_op_desc->Inputs().count(name) == 0 ||
-            next_op_desc->Input(name).size() == 0)
-          continue;
-        auto var_name = next_op_desc->Input(name)[0];
-        if (var_name.compare(quant_out_var_name) == 0) {
-          next_op_desc->SetInput(
-              name, std::vector<std::string>({dequant_in->Name()}));
-          break;
-        }
+        auto input_names = next_op_desc->Input(name);
+        std::replace(input_names.begin(), input_names.end(), quant_out_var_name,
+                     dequant_in->Name());
+        next_op_desc->SetInput(name, input_names);
       }
 
       if (keep_dequant)

paddle/fluid/inference/api/mkldnn_quantizer.cc

@@ -50,40 +50,46 @@ bool AnalysisPredictor::MkldnnQuantizer::CalculateScales() {
 
       auto glambda = [&](const VariableNameMap& connections, bool is_output) {
         for (auto const& conn : connections) {
-          if (conn.second.size() == 0) continue;
-          auto& var_name = conn.second[0];
-
-          // skip if scale already computed
-          if (scales_.find(var_name) != scales_.end()) return;
-
-          auto* var = predictor_.sub_scope_->FindVar(var_name);
-          PADDLE_ENFORCE(var, "%s is not in the scope", var_name);
-          PADDLE_ENFORCE(var->IsType<LoDTensor>(),
-                         "Only support lod tensor now.");
-          LoDTensor* var_tensor = var->GetMutable<LoDTensor>();
-
-          // force unsigned type if already know it
-          bool is_unsigned = false;
-          if (is_output && op->Type() == "conv2d") {
-            // output of conv2d with relu must be unsigned
-            is_unsigned = op->HasAttr("fuse_relu") &&
-                          boost::get<bool>(op->GetAttr("fuse_relu"));
-          } else if (is_output && op->Type() == "pool2d") {
-            // output of pool2d with unsigned input must be unsigned
-            auto input_var_name = op->Input("X")[0];
-            if (scales_.find(input_var_name) != scales_.end()) {
-              is_unsigned = scales_[input_var_name].first;
+          for (const auto& var_name : conn.second) {
+            // skip if scale already computed
+            if (scales_.find(var_name) != scales_.end()) return;
+
+            auto* var = predictor_.sub_scope_->FindVar(var_name);
+            PADDLE_ENFORCE(var, "%s is not in the scope", var_name);
+            PADDLE_ENFORCE(var->IsType<LoDTensor>(),
+                           "Only support lod tensor now.");
+            LoDTensor* var_tensor = var->GetMutable<LoDTensor>();
+
+            // force unsigned type if already know it
+            bool is_unsigned = false;
+            if (is_output && op->Type() == "conv2d") {
+              // output of conv2d with relu must be unsigned
+              is_unsigned = op->HasAttr("fuse_relu") &&
+                            boost::get<bool>(op->GetAttr("fuse_relu"));
+            } else if (is_output && op->Type() == "relu") {
+              is_unsigned = true;
+            } else if (is_output &&
+                       (op->Type() == "pool2d" || op->Type() == "transpose2" ||
+                        op->Type() == "reshape2" || op->Type() == "concat")) {
+              // output of ops with unsigned input must be unsigned
+              is_unsigned = true;
+              for (auto input_var_name : op->Input("X")) {
+                PADDLE_ENFORCE(scales_.find(input_var_name) != scales_.end(),
+                               "Input scales must be calculated before the "
+                               "output scales to infer if output is unsigned.");
+                is_unsigned = is_unsigned && scales_[input_var_name].first;
+              }
             }
-          }
 
-          CalculateSingleScale(op->Type(), conn.first, var_name, *var_tensor,
-                               is_unsigned);
+            CalculateSingleScale(op->Type(), conn.first, var_name, *var_tensor,
+                                 is_unsigned);
+          }
         }
       };
 
-      // handle outputs first so unsigned outputs could be inferred
-      glambda(connections_out, true /* is_output */);
+      // handle inputs first to let is_unsigned be inferred for the outputs
       glambda(connections_in, false /* is_output */);
+      glambda(connections_out, true /* is_output */);
     }
   }
 

paddle/fluid/inference/api/mkldnn_quantizer_config.cc

@@ -22,10 +22,13 @@ MkldnnQuantizerConfig::MkldnnQuantizerConfig() {
   rules_["conv2d"]["Filter"] = ScaleAlgo::MAX_CH;
   rules_["conv2d"]["Bias"] = ScaleAlgo::NONE;  // do not compute scale
   rules_["conv2d"]["ResidualData"] = ScaleAlgo::KL;
-  rules_["conv2d"]["Output"] = ScaleAlgo::KL;  // do not compute scale
+  rules_["conv2d"]["Output"] = ScaleAlgo::KL;
 
   rules_["pool2d"]["X"] = ScaleAlgo::KL;
-  rules_["pool2d"]["Out"] = ScaleAlgo::KL;  // do not compute scale
+  rules_["pool2d"]["Out"] = ScaleAlgo::KL;
+
+  rules_["concat"]["X"] = ScaleAlgo::KL;
+  rules_["concat"]["Out"] = ScaleAlgo::KL;
 }
 
 ScaleAlgo MkldnnQuantizerConfig::scale_algo(

paddle/fluid/operators/concat_op.cc

@@ -117,6 +117,12 @@ class ConcatOpMaker : public framework::OpProtoAndCheckerMaker {
     AddAttr<int>("axis",
                  "The axis along which the input tensors will be concatenated.")
         .SetDefault(0);
+    AddAttr<bool>("use_quantizer",
+                  "(bool, default false) "
+                  "Set to true for operators that should be quantized and use "
+                  "int8 kernel. "
+                  "Only used on CPU.")
+        .SetDefault(false);
     AddComment(R"DOC(
 Concat Operator.