Minor fix of warnings raised by -Wreturn-std-move and -Wself-assign-overloaded

nnvm/src/pass/infer_shape_type.cc

@@ -199,7 +199,7 @@ Graph InferAttr(Graph &&ret,
   ret.attrs[attr_name] = std::make_shared<any>(std::move(rshape));
   // number of nodes who knows the shape.
   ret.attrs[unknown_name] = std::make_shared<any>(num_unknown);
-  return ret;
+  return std::move(ret);
 }
 
 NNVM_REGISTER_PASS(InferShape)

src/codegen/verilog/verilog_ir.cc

@@ -46,7 +46,7 @@ class StageInputReplacer : public IRMutator {
     Var new_var(it->second->var->name_hint + ".sync", op->type);
     inputs_.Set(new_var, it->second);
     replace_[op] = new_var;
-    return new_var;
+    return std::move(new_var);
   }
   Expr Mutate_(const Load* op, const Expr& e) final {
     CHECK(is_zero(op->index))
@@ -60,7 +60,7 @@ class StageInputReplacer : public IRMutator {
     Var data(it->second->var->name_hint + ".load.sync", op->type);
     inputs_.Set(data, it->second);
     replace_[op->buffer_var.get()] = data;
-    return data;
+    return std::move(data);
   }
   // inputs that get replaced.
   Map<Var, StageInput> inputs_;

src/pass/combine_context_call.cc

@@ -39,7 +39,7 @@ class ContextCallCombiner final : public IRMutator {
         }
         Var ctx_var(name, ctx.type());
         ctx_map_[ctx] = ctx_var;
-        return ctx_var;
+        return std::move(ctx_var);
       }
     } else {
       return IRMutator::Mutate_(op, e);

src/relay/ir/expr_functor.cc

@@ -364,7 +364,7 @@ class ExprBinder : public ExprMutator {
     if (it != args_map_.end()) {
       return (*it).second;
     } else {
-      return id;
+      return std::move(id);
     }
   }
 

src/relay/ir/type_functor.cc

@@ -192,7 +192,7 @@ class TypeBinder : public TypeMutator {
     if (it != args_map_.end()) {
       return (*it).second;
     } else {
-      return id;
+      return std::move(id);
     }
   }
 

src/relay/pass/alter_op_layout.cc

@@ -34,7 +34,7 @@ Expr TransformLayout(Expr raw, Layout src_layout, Layout dst_layout) {
   attrs->src_layout = src_layout.name();
   attrs->dst_layout = dst_layout.name();
   Call transform = CallNode::make(transform_op, {raw}, Attrs{attrs});
-  return transform;
+  return std::move(transform);
 }
 
 // Memorize layout transform so we can reuse internal transformed nodes

src/relay/pass/fuse_ops.cc

@@ -773,7 +773,7 @@ class FuseMutator : private ExprMutator {
       } else {
         // This is an intermediate node of a fused function
         // simply return the new call.
-        return new_call;
+        return std::move(new_call);
       }
     } else {
       return ExprMutator::VisitExpr_(call);

src/relay/pass/to_a_normal_form.cc

@@ -398,7 +398,7 @@ class Fill : ExprFunctor<Expr(const Expr&, const Var&)> {
       visited_->insert(gv);
       mod_->Update(gv, Downcast<Function>(relay::ToANormalForm(mod_->Lookup(gv), mod_, visited_)));
     }
-    return gv;
+    return std::move(gv);
   }
 
   Expr VisitExpr_(const OpNode* op, const Var& v) final {

src/relay/pass/type_infer.cc

@@ -724,7 +724,7 @@ Expr InferType(const Expr& expr, const Module& mod_ref) {
     // FromExpr wraps a naked expression as a function, we will unbox
     // it here.
     if (expr.as<FunctionNode>()) {
-      return func;
+      return std::move(func);
     } else {
       return func->body;
     }

topi/include/topi/nn/l2_normalize.h

@@ -39,7 +39,7 @@ inline Tensor l2_normalize(const Tensor& data,
                       topi::sqrt(tvm::compute(expand_sum->shape,
                                               [&](const Array<Var>& i){
                                                 return (max(expand_sum(i), eps));
-                                              }, name = name, tag = tag)));
+                                              }, name, tag)));
 }
 }  // namespace nn
 }  // namespace topi