feat(mgb/opr): add megbrain fake quant opr

GitOrigin-RevId: a858bce939c7a68e311bbaf8417ce3feb2227537

src/opr/impl/dnn/dnn.oprdecl

@@ -315,5 +315,9 @@ r"""
 """),
          has_out_dtype=True)
 
+decl_opr('FakeQuant',
+         inputs=[Doc('src','input tenosr'),Doc('scale','scale tensor'),Doc('zero_point','zero point tensor')],
+         params='FakeQuant')
+
 
 # vim: ft=python

src/opr/impl/dnn/dnn.sereg.h

@@ -18,6 +18,7 @@
 #include "megbrain/opr/dnn/roi_align.h"
 #include "megbrain/opr/dnn/local.h"
 #include "megbrain/opr/dnn/lrn.h"
+#include "megbrain/opr/dnn/fake_quant.h"
 
 #include "megbrain/serialization/sereg.h"
 
@@ -423,6 +424,8 @@ namespace opr {
     MGB_SEREG_OPR(DeformablePSROIPoolingBackward, 5);
 
     MGB_SEREG_OPR(BatchConvBiasForward, 0);
+    MGB_SEREG_OPR(FakeQuant, 3);
+    MGB_SEREG_OPR(FakeQuantBackward, 4);
 } // namespace opr
 
 

src/opr/impl/dnn/fake_quant.cpp

+/**
+ * \file src/opr/impl/dnn/fake_quant.cpp
+ * MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
+ *
+ * Copyright (c) 2014-2020 Megvii Inc. All rights reserved.
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ */
+
+#include "megbrain/opr/dnn/fake_quant.h"
+#include "../internal/megdnn_opr_wrapper.inl"
+#include "megbrain/graph/grad_impl.h"
+#include "megbrain/opr/internal/out_shape_by_sym_var.h"
+#include "megbrain/opr/utility.h"
+
+using namespace mgb;
+using namespace opr;
+
+MGB_DYN_TYPE_OBJ_FINAL_IMPL(FakeQuantForward);
+MEGDNN_OPR_INIT3(FakeQuantForward, "fakequant_fwd");
+
+#ifdef MGB_ENABLE_GRAD
+MGB_IMPL_OPR_GRAD(FakeQuantForward) {
+    if (wrt_idx == 0) {
+        // wrt src
+        SymbolVar grad =
+                FakeQuantBackward::make(out_grad[0], opr.input(0), opr.input(1),
+                                        opr.input(2), opr.param());
+        return grad.node();
+    } else {
+        return nullptr;
+    }
+}
+#endif
+
+MGB_DYN_TYPE_OBJ_FINAL_IMPL(FakeQuantBackward);
+MEGDNN_OPR_INIT4(FakeQuantBackward, "fakequant_bwd", 1, true);

src/opr/include/megbrain/opr/dnn/fake_quant.h

+/**
+ * \file src/opr/include/megbrain/opr/dnn/fake_quant.h
+ * MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
+ *
+ * Copyright (c) 2014-2020 Megvii Inc. All rights reserved.
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ */
+
+#pragma once
+#include "megbrain/opr/internal/megdnn_opr_wrapper.h"
+#include "megdnn/oprs.h"
+namespace mgb {
+namespace opr {
+MGB_DEFINE_OPR_CLASS(FakeQuantForward,
+                     intl::MegDNNOprWrapperFwd<megdnn::FakeQuantForward>) // {
+public:
+FakeQuantForward(VarNode* src, VarNode* scale, VarNode* zero_point,
+                 const Param& param, const OperatorNodeConfig& config);
+
+static SymbolVar make(SymbolVar src, SymbolVar scale, SymbolVar zero_point,
+                      const Param& param = {},
+                      const OperatorNodeConfig& config = {});
+};  // namespace opr
+using FakeQuant = FakeQuantForward;
+
+MGB_DEFINE_OPR_CLASS(FakeQuantBackward,
+                     intl::MegDNNOprWrapperBwd<megdnn::FakeQuantBackward>) // {
+public:
+FakeQuantBackward(VarNode* diff, VarNode* input, VarNode* scale,
+                  VarNode* zero_point, const Param& param,
+                  const OperatorNodeConfig& config);
+
+static SymbolVar make(SymbolVar diff, SymbolVar input, SymbolVar scale,
+                      SymbolVar zero_point, const Param& param = {},
+                      const OperatorNodeConfig& config = {});
+
+};
+
+}  // namespace mgb
+}  // namespace opr
\ No newline at end of file

src/serialization/impl/schema.fbs

@@ -102,6 +102,7 @@ union OperatorParam {
     param.AdaptivePooling = 70,
     param.NvOf = 71,
     param.DctChannelSelect = 72,
+    param.FakeQuant = 73,
 }
 
 table Operator {