Use const refs where possible

CMakeLists.txt

@@ -70,7 +70,7 @@ rocm_enable_clang_tidy(
         -modernize-pass-by-value
         -modernize-use-default-member-init
         -modernize-use-transparent-functors
-        -performance-unnecessary-value-param
+        # -performance-unnecessary-value-param
         -readability-braces-around-statements
         -readability-else-after-return
         -readability-named-parameter

src/eliminate_contiguous.cpp

@@ -5,10 +5,11 @@
 #include <migraph/iterator_for.hpp>
 #include <migraph/ranges.hpp>
 #include <migraph/stringutils.hpp>
+#include <utility>
 
 namespace migraph {
 
-bool try_compute_shape(operation op, std::vector<instruction_ref> args)
+bool try_compute_shape(const operation& op, const std::vector<instruction_ref>& args)
 {
     try
     {

src/include/migraph/argument.hpp

@@ -4,6 +4,7 @@
 #include <migraph/shape.hpp>
 #include <migraph/raw_data.hpp>
 #include <functional>
+#include <utility>
 
 namespace migraph {
 
@@ -18,16 +19,16 @@ struct argument : raw_data<argument>
 {
     argument() {}
 
-    argument(shape s) : m_shape(s)
+    argument(const shape& s) : m_shape(s)
     {
         std::vector<char> buffer(s.bytes());
         // TODO: Move vector
         data = [=]() mutable { return buffer.data(); };
     }
 
-    argument(shape s, std::function<char*()> d) : data(d), m_shape(s) {}
+    argument(shape s, std::function<char*()> d) : data(std::move(d)), m_shape(std::move(s)) {}
     template <class T>
-    argument(shape s, T* d) : data([d] { return reinterpret_cast<char*>(d); }), m_shape(s)
+    argument(shape s, T* d) : data([d] { return reinterpret_cast<char*>(d); }), m_shape(std::move(s))
     {
     }
 

src/include/migraph/builtin.hpp

@@ -12,24 +12,24 @@ namespace builtin {
 struct literal
 {
     std::string name() const { return "@literal"; }
-    shape compute_shape(std::vector<shape>) const { MIGRAPH_THROW("builtin"); }
-    argument compute(context&, shape, std::vector<argument>) const { MIGRAPH_THROW("builtin"); }
+    shape compute_shape(const std::vector<shape>&) const { MIGRAPH_THROW("builtin"); }
+    argument compute(context&, const shape&, const std::vector<argument>&) const { MIGRAPH_THROW("builtin"); }
 };
 
 struct outline
 {
     shape s;
     std::string name() const { return "@outline"; }
-    shape compute_shape(std::vector<shape>) const { return s; }
-    argument compute(context&, shape, std::vector<argument>) const { MIGRAPH_THROW("builtin"); }
+    shape compute_shape(const std::vector<shape>&) const { return s; }
+    argument compute(context&, const shape&, const std::vector<argument>&) const { MIGRAPH_THROW("builtin"); }
 };
 
 struct param
 {
     std::string parameter;
     std::string name() const { return "@param"; }
-    shape compute_shape(std::vector<shape>) const { MIGRAPH_THROW("builtin"); }
-    argument compute(context&, shape, std::vector<argument>) const { MIGRAPH_THROW("builtin"); }
+    shape compute_shape(const std::vector<shape>&) const { MIGRAPH_THROW("builtin"); }
+    argument compute(context&, const shape&, const std::vector<argument>&) const { MIGRAPH_THROW("builtin"); }
     friend std::ostream& operator<<(std::ostream& os, const param& op)
     {
         os << op.name() << ":" << op.parameter;

src/include/migraph/check_context.hpp

@@ -11,8 +11,8 @@ struct check_context
     struct op
     {
         std::string name() const { return "check_context"; }
-        shape compute_shape(std::vector<shape>) const { return {}; }
-        argument compute(context& ctx, shape, std::vector<argument>) const
+        shape compute_shape(const std::vector<shape>&) const { return {}; }
+        argument compute(context& ctx, const shape&, const std::vector<argument>&) const
         {
             T* x = any_cast<T>(&ctx);
             if(x == nullptr)

src/include/migraph/errors.hpp

@@ -10,7 +10,7 @@ namespace migraph {
 /// Represents exceptions that can be thrown by migraphlib
 struct exception : std::runtime_error
 {
-    exception(std::string msg = "") : std::runtime_error(msg) {}
+    exception(const std::string& msg = "") : std::runtime_error(msg) {}
 };
 
 /**
@@ -20,7 +20,7 @@ struct exception : std::runtime_error
  * @param message Custom message for the error
  * @return Exceptions
  */
-inline exception make_exception(std::string context, std::string message = "")
+inline exception make_exception(const std::string& context, const std::string& message = "")
 {
     return {context + ": " + message};
 }

src/include/migraph/generate.hpp

@@ -31,7 +31,7 @@ struct xorshf96_generator
 };
 
 template <class T>
-std::vector<T> generate_tensor_data(migraph::shape s, std::mt19937::result_type)
+std::vector<T> generate_tensor_data(const migraph::shape& s, std::mt19937::result_type)
 {
     std::vector<T> result(s.elements());
     std::generate(result.begin(), result.end(), xorshf96_generator<T>{});

src/include/migraph/instruction.hpp

@@ -8,10 +8,11 @@
 #include <migraph/operation.hpp>
 #include <migraph/erase.hpp>
 #include <string>
+#include <utility>
 
 namespace migraph {
 
-shape compute_shape(operation op, std::vector<instruction_ref> args);
+shape compute_shape(const operation& op, const std::vector<instruction_ref>& args);
 
 struct instruction
 {
@@ -25,14 +26,14 @@ struct instruction
     instruction(literal l) : op(builtin::literal{}), result(l.get_shape()), lit(std::move(l)) {}
 
     // internal
-    void replace(operation o, shape r, std::vector<instruction_ref> args)
+    void replace(operation o, const shape& r, std::vector<instruction_ref> args)
     {
-        op = o;
-        replace(std::move(r));
+        op = std::move(o);
+        replace(r);
         replace(std::move(args));
     }
 
-    void replace(shape r)
+    void replace(const shape& r)
     {
         if(r != result)
         {
@@ -155,7 +156,7 @@ inline void replace_argument(instruction_ref ins, instruction_ref old, instructi
 
 // TODO: Move to a cpp file
 // TODO: Use const ref for vector
-inline shape compute_shape(operation op, std::vector<instruction_ref> args)
+inline shape compute_shape(const operation& op, const std::vector<instruction_ref>& args)
 {
     std::vector<shape> shapes(args.size());
     std::transform(

src/include/migraph/literal.hpp

@@ -27,7 +27,7 @@ struct literal : raw_data<literal>
     }
 
     template <class T>
-    literal(shape s, const std::vector<T>& x)
+    literal(const shape& s, const std::vector<T>& x)
         : buffer(std::make_unique<char[]>(s.bytes())), m_shape(s)
     {
         static_assert(std::is_trivial<T>{}, "Literals can only be trivial types");
@@ -35,7 +35,7 @@ struct literal : raw_data<literal>
     }
 
     template <class T>
-    literal(shape s, const std::initializer_list<T>& x)
+    literal(const shape& s, const std::initializer_list<T>& x)
         : buffer(std::make_unique<char[]>(s.bytes())), m_shape(s)
     {
         static_assert(std::is_trivial<T>{}, "Literals can only be trivial types");
@@ -43,13 +43,13 @@ struct literal : raw_data<literal>
     }
 
     template <class Iterator>
-    literal(shape s, Iterator start, Iterator end)
+    literal(const shape& s, Iterator start, Iterator end)
         : buffer(std::make_unique<char[]>(s.bytes())), m_shape(s)
     {
         fill(start, end);
     }
 
-    literal(shape s, const char* x) : buffer(std::make_unique<char[]>(s.bytes())), m_shape(s)
+    literal(const shape& s, const char* x) : buffer(std::make_unique<char[]>(s.bytes())), m_shape(s)
     {
         std::copy(x, x + s.bytes(), buffer.get());
     }

src/include/migraph/operation.hpp

@@ -25,7 +25,7 @@ struct operation
     /// This is used to compute the resulting shape from an operation. If an
     /// operation cannot be run with input shapes, then it should throw an
     /// exception.
-    shape compute_shape(std::vector<shape> input) const;
+    shape compute_shape(const std::vector<shape>& input) const;
     /**
      * @brief This performs the operation's computation
      *
@@ -37,7 +37,7 @@ struct operation
      * @return Return an `argument` of the result computation. The `shape` of `argument` should be
      * the same the `output` shape.
      */
-    argument compute(context& ctx, shape output, std::vector<argument> input) const;
+    argument compute(context& ctx, const shape& output, const std::vector<argument>& input) const;
     /// An optional stream operator to print the operation. When this is not
     /// implemented, it will just print the operation's name.
     friend std::ostream& operator<<(std::ostream& os, const operation& op);
@@ -56,7 +56,8 @@ auto operator<<(std::ostream& os, const T& x) -> decltype(os << x.name())
 } // namespace operation_stream
 
 template <class T>
-argument compute_op(const T& x, context& ctx, shape output_shape, std::vector<argument> input)
+argument
+compute_op(const T& x, context& ctx, const shape& output_shape, const std::vector<argument>& input)
 {
     return x.compute(auto_any_cast(ctx), output_shape, input);
 }
@@ -67,8 +68,8 @@ argument compute_op(const T& x, context& ctx, shape output_shape, std::vector<ar
  * struct operation
  * {
  *      std::string name() const;
- *      shape compute_shape(std::vector<shape> input) const;
- *      argument compute(context& ctx,shape output,std::vector<argument> input) const;
+ *      shape compute_shape(const std::vector<shape>& input) const;
+ *      argument compute(context& ctx,const shape& output,const std::vector<argument>& input) const;
  *     friend std::ostream & operator<<(std::ostream & os,const operation & op) ;
  * };
  *
@@ -137,17 +138,16 @@ struct operation
         return (*this).private_detail_te_get_handle().name();
     }
 
-    shape compute_shape(std::vector<shape> input) const
+    shape compute_shape(const std::vector<shape>& input) const
     {
         assert((*this).private_detail_te_handle_mem_var);
-        return (*this).private_detail_te_get_handle().compute_shape(std::move(input));
+        return (*this).private_detail_te_get_handle().compute_shape(input);
     }
 
-    argument compute(context& ctx, shape output, std::vector<argument> input) const
+    argument compute(context& ctx, const shape& output, const std::vector<argument>& input) const
     {
         assert((*this).private_detail_te_handle_mem_var);
-        return (*this).private_detail_te_get_handle().compute(
-            ctx, std::move(output), std::move(input));
+        return (*this).private_detail_te_get_handle().compute(ctx, output, input);
     }
 
     friend std::ostream& operator<<(std::ostream& os, const operation& op)
@@ -164,8 +164,9 @@ struct operation
         virtual const std::type_info& type() const                                = 0;
 
         virtual std::string name() const                                   = 0;
-        virtual shape compute_shape(std::vector<shape> input) const                             = 0;
-        virtual argument compute(context& ctx, shape output, std::vector<argument> input) const = 0;
+        virtual shape compute_shape(const std::vector<shape>& input) const = 0;
+        virtual argument
+        compute(context& ctx, const shape& output, const std::vector<argument>& input) const = 0;
         virtual std::ostream& operator_shift_left(std::ostream& os) const                    = 0;
     };
 
@@ -199,16 +200,18 @@ struct operation
 
         std::string name() const override { return private_detail_te_value.name(); }
 
-        shape compute_shape(std::vector<shape> input) const override
+        shape compute_shape(const std::vector<shape>& input) const override
         {
 
-            return private_detail_te_value.compute_shape(std::move(input));
+            return private_detail_te_value.compute_shape(input);
         }
 
-        argument compute(context& ctx, shape output, std::vector<argument> input) const override
+        argument compute(context& ctx,
+                         const shape& output,
+                         const std::vector<argument>& input) const override
         {
 
-            return compute_op(private_detail_te_value, ctx, std::move(output), std::move(input));
+            return compute_op(private_detail_te_value, ctx, output, input);
         }
 
         std::ostream& operator_shift_left(std::ostream& os) const override

src/include/migraph/operators.hpp

@@ -7,12 +7,13 @@
 #include <migraph/stringutils.hpp>
 #include <migraph/streamutils.hpp>
 #include <cmath>
+#include <utility>
 
 namespace migraph {
 
 struct not_computable
 {
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -41,7 +42,7 @@ struct batch_norm_inference
         return inputs.front();
     }
 
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -114,7 +115,7 @@ struct convolution
         }
     }
 
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -165,7 +166,7 @@ struct pooling
                 }};
     }
 
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -191,7 +192,7 @@ struct activation
         return inputs.front();
     }
 
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -234,7 +235,7 @@ struct transpose
     }
     argument compute(context&, shape output_shape, std::vector<argument> args) const
     {
-        return {output_shape, std::move(args.front().data)};
+        return {std::move(output_shape), std::move(args.front().data)};
     }
     friend std::ostream& operator<<(std::ostream& os, const transpose& op)
     {
@@ -259,7 +260,7 @@ struct contiguous
         }
         return {t, lens};
     }
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -306,7 +307,7 @@ struct reshape
 
     argument compute(context&, shape output_shape, std::vector<argument> args) const
     {
-        return {output_shape, std::move(args.front().data)};
+        return {std::move(output_shape), std::move(args.front().data)};
     }
 
     friend std::ostream& operator<<(std::ostream& os, const reshape& op)
@@ -336,7 +337,7 @@ struct gemm
         return {t, {a.lens()[0], b.lens()[1]}};
     }
 
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -356,7 +357,7 @@ struct unary
         check_shapes{inputs}.has(1);
         return inputs.at(0);
     }
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -448,7 +449,7 @@ struct flatten
     }
     argument compute(context&, shape output_shape, std::vector<argument> args) const
     {
-        return {output_shape, std::move(args.front().data)};
+        return {std::move(output_shape), std::move(args.front().data)};
     }
     friend std::ostream& operator<<(std::ostream& os, const flatten& op)
     {
@@ -488,7 +489,7 @@ struct broadcast
     }
     argument compute(context&, shape output_shape, std::vector<argument> args) const
     {
-        return {output_shape, std::move(args.at(1).data)};
+        return {std::move(output_shape), std::move(args.at(1).data)};
     }
     friend std::ostream& operator<<(std::ostream& os, const broadcast& op)
     {
@@ -507,7 +508,7 @@ struct binary
         check_shapes{inputs}.has(2).same_type().same_dims();
         return inputs.at(0);
     }
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -537,12 +538,12 @@ struct outline
 {
     shape s;
     std::string name() const { return "outline"; }
-    shape compute_shape(std::vector<shape> inputs) const
+    shape compute_shape(const std::vector<shape>& inputs) const
     {
         check_shapes{inputs, *this}.has(0);
         return s;
     }
-    argument compute(context&, shape, std::vector<argument>) const { return {s, nullptr}; }
+    argument compute(context&, const shape&, const std::vector<argument>&) const { return {s, nullptr}; }
 };
 
 } // namespace migraph

src/include/migraph/program.hpp

@@ -34,7 +34,7 @@ struct program
     {
         return add_instruction(op, {args...});
     }
-    instruction_ref add_instruction(operation op, std::vector<instruction_ref> args);
+    instruction_ref add_instruction(const operation& op, std::vector<instruction_ref> args);
 
     template <class... Ts>
     instruction_ref insert_instruction(instruction_ref ins, operation op, Ts... args)
@@ -42,7 +42,7 @@ struct program
         return insert_instruction(ins, op, {args...});
     }
     instruction_ref
-    insert_instruction(instruction_ref ins, operation op, std::vector<instruction_ref> args);
+    insert_instruction(instruction_ref ins, const operation& op, std::vector<instruction_ref> args);
 
     template <class... Ts>
     instruction_ref replace_instruction(instruction_ref ins, operation op, Ts... args)
@@ -50,7 +50,7 @@ struct program
         return replace_instruction(ins, op, {args...});
     }
     instruction_ref
-    replace_instruction(instruction_ref ins, operation op, std::vector<instruction_ref> args);
+    replace_instruction(instruction_ref ins, const operation& op, std::vector<instruction_ref> args);
 
     instruction_ref replace_instruction(instruction_ref ins, instruction_ref rep);
 
@@ -67,7 +67,7 @@ struct program
 
     instruction_ref add_literal(literal l);
 
-    instruction_ref add_outline(shape s);
+    instruction_ref add_outline(const shape& s);
 
     instruction_ref add_parameter(std::string name, shape s);
 

src/include/migraph/stringutils.hpp

@@ -29,7 +29,7 @@ inline bool ends_with(const std::string& value, const std::string& suffix)
 }
 
 template <class Strings>
-inline std::string join_strings(Strings strings, std::string delim)
+inline std::string join_strings(Strings strings, const std::string& delim)
 {
     auto it = strings.begin();
     if(it == strings.end())
@@ -57,7 +57,7 @@ inline bool starts_with(const std::string& value, const std::string& prefix)
         return std::equal(prefix.begin(), prefix.end(), value.begin());
 }
 
-inline std::string remove_prefix(std::string s, std::string prefix)
+inline std::string remove_prefix(std::string s, const std::string& prefix)
 {
     if(starts_with(s, prefix))
         return s.substr(prefix.length());

src/include/migraph/tensor_view.hpp

@@ -6,6 +6,7 @@
 #include <migraph/requires.hpp>
 
 #include <iostream>
+#include <utility>
 
 namespace migraph {
 
@@ -14,7 +15,7 @@ struct tensor_view
 {
     using value_type = T;
     tensor_view() : m_data(nullptr) {}
-    tensor_view(shape s, T* d) : m_data(d), m_shape(s) {}
+    tensor_view(shape s, T* d) : m_data(d), m_shape(std::move(s)) {}
 
     const shape& get_shape() const { return this->m_shape; }
 

src/onnx/mnist.cpp

@@ -20,7 +20,7 @@ auto reverse_int(unsigned int i)
            (static_cast<unsigned int>(c3) << 8u) + c4;
 };
 
-std::vector<float> read_mnist_images(std::string full_path, int& number_of_images, int& image_size)
+std::vector<float> read_mnist_images(const std::string& full_path, int& number_of_images, int& image_size)
 {
     using uchar = unsigned char;
 
@@ -63,7 +63,7 @@ std::vector<float> read_mnist_images(std::string full_path, int& number_of_image
     }
 }
 
-std::vector<int32_t> read_mnist_labels(std::string full_path, int& number_of_labels)
+std::vector<int32_t> read_mnist_labels(const std::string& full_path, int& number_of_labels)
 {
     using uchar = unsigned char;
 

src/onnx/onnx.cpp

@@ -6,6 +6,7 @@
 #include <unordered_map>
 #include <functional>
 #include <array>
+#include <utility>
 #include <vector>
 
 #include <migraph/fallthrough.hpp>
@@ -27,7 +28,7 @@ struct unknown
         else
             return input.front();
     }
-    argument compute(context&, shape, std::vector<argument>) const
+    argument compute(context&, const shape&, const std::vector<argument>&) const
     {
         MIGRAPH_THROW("not computable");
     }
@@ -103,7 +104,7 @@ struct onnx_parser
     }
 
     instruction_ref
-    parse_conv(std::string, attribute_map attributes, std::vector<instruction_ref> args)
+    parse_conv(const std::string&, attribute_map attributes, std::vector<instruction_ref> args)
     {
         convolution op;
         if(contains(attributes, "pads"))
@@ -129,7 +130,7 @@ struct onnx_parser
     }
 
     instruction_ref
-    parse_pooling(std::string name, attribute_map attributes, std::vector<instruction_ref> args)
+    parse_pooling(const std::string& name, attribute_map attributes, std::vector<instruction_ref> args)
     {
         pooling op{name == "MaxPool" ? "max" : "average"};
         if(contains(attributes, "pads"))
@@ -144,11 +145,11 @@ struct onnx_parser
         {
             copy(attributes["kernel_shape"].ints(), op.lengths.begin());
         }
-        return prog.add_instruction(op, args);
+        return prog.add_instruction(op, std::move(args));
     }
 
     instruction_ref
-    parse_reshape(std::string, attribute_map attributes, std::vector<instruction_ref> args)
+    parse_reshape(const std::string&, attribute_map attributes, std::vector<instruction_ref> args)
     {
         reshape op;
         if(args.size() == 1)
@@ -165,7 +166,7 @@ struct onnx_parser
     }
 
     instruction_ref
-    parse_flatten(std::string, attribute_map attributes, std::vector<instruction_ref> args)
+    parse_flatten(const std::string&, attribute_map attributes, std::vector<instruction_ref> args)
     {
         uint64_t axis = 0;
         if(contains(attributes, "axis"))
@@ -176,14 +177,14 @@ struct onnx_parser
     }
 
     instruction_ref
-    parse_constant(std::string, attribute_map attributes, std::vector<instruction_ref>)
+    parse_constant(const std::string&, attribute_map attributes, const std::vector<instruction_ref>&)
     {
         literal v = parse_value(attributes.at("value"));
         return prog.add_literal(v);
     }
 
     instruction_ref
-    parse_gemm(std::string, attribute_map attributes, std::vector<instruction_ref> args)
+    parse_gemm(const std::string&, attribute_map attributes, std::vector<instruction_ref> args)
     {
         float alpha = 1.0f;
         float beta  = 0.0f;
@@ -219,7 +220,7 @@ struct onnx_parser
     }
 
     instruction_ref
-    parse_batchnorm(std::string, attribute_map attributes, std::vector<instruction_ref> args)
+    parse_batchnorm(const std::string&, attribute_map attributes, std::vector<instruction_ref> args)
     {
         float epsilon                                 = 1e-5f;
         float momentum                                = 0.9f;
@@ -244,7 +245,7 @@ struct onnx_parser
                           : batch_norm_inference::per_activation;
         }
         batch_norm_inference op{epsilon, momentum, bn_mode, is_test};
-        return prog.add_instruction(op, args);
+        return prog.add_instruction(op, std::move(args));
     }
 
     void parse_from(std::istream& is)
@@ -293,7 +294,7 @@ struct onnx_parser
         }
     }
 
-    void parse_node(std::string name)
+    void parse_node(const std::string& name)
     {
         if(name.empty())
             MIGRAPH_THROW("Onnx node must have a name");

src/onnx/verify_onnx.cpp

@@ -7,7 +7,7 @@
 #include <migraph/generate.hpp>
 #include <migraph/verify.hpp>
 
-migraph::argument run_cpu(std::string file)
+migraph::argument run_cpu(const std::string& file)
 {
     auto p = migraph::parse_onnx(file);
     p.compile(migraph::cpu::cpu_target{});
@@ -21,7 +21,7 @@ migraph::argument run_cpu(std::string file)
     return out;
 }
 
-migraph::argument run_gpu(std::string file)
+migraph::argument run_gpu(const std::string& file)
 {
     auto p = migraph::parse_onnx(file);
     p.compile(migraph::gpu::target{});

src/program.cpp

@@ -7,6 +7,7 @@
 #include <iostream>
 #include <sstream>
 #include <algorithm>
+#include <utility>
 
 namespace migraph {
 
@@ -76,12 +77,12 @@ program::program(program&&) noexcept = default;
 program& program::operator=(program&&) noexcept = default;
 program::~program() noexcept                    = default;
 
-instruction_ref program::add_instruction(operation op, std::vector<instruction_ref> args)
+instruction_ref program::add_instruction(const operation& op, std::vector<instruction_ref> args)
 {
-    return insert_instruction(impl->instructions.end(), std::move(op), std::move(args));
+    return insert_instruction(impl->instructions.end(), op, std::move(args));
 }
 instruction_ref
-program::insert_instruction(instruction_ref ins, operation op, std::vector<instruction_ref> args)
+program::insert_instruction(instruction_ref ins, const operation& op, std::vector<instruction_ref> args)
 {
     assert(std::all_of(
                args.begin(), args.end(), [&](instruction_ref x) { return has_instruction(x); }) &&
@@ -97,7 +98,7 @@ program::insert_instruction(instruction_ref ins, operation op, std::vector<instr
 }
 
 instruction_ref
-program::replace_instruction(instruction_ref ins, operation op, std::vector<instruction_ref> args)
+program::replace_instruction(instruction_ref ins, const operation& op, std::vector<instruction_ref> args)
 {
     assert(std::all_of(
                args.begin(), args.end(), [&](instruction_ref x) { return has_instruction(x); }) &&
@@ -168,7 +169,7 @@ instruction_ref program::add_literal(literal l)
     return impl->instructions.begin();
 }
 
-instruction_ref program::add_outline(shape s)
+instruction_ref program::add_outline(const shape& s)
 {
     impl->instructions.push_front({builtin::outline{s}, s, {}});
     return impl->instructions.begin();
@@ -176,7 +177,7 @@ instruction_ref program::add_outline(shape s)
 
 instruction_ref program::add_parameter(std::string name, shape s)
 {
-    impl->instructions.push_front({builtin::param{std::move(name)}, s, {}});
+    impl->instructions.push_front({builtin::param{std::move(name)}, std::move(s), {}});
     return impl->instructions.begin();
 }
 
@@ -317,7 +318,7 @@ argument generic_eval(const program& p,
 
 argument program::eval(std::unordered_map<std::string, argument> params) const
 {
-    return generic_eval(*this, this->impl->ctx, params, [](auto&, auto f) { return f(); });
+    return generic_eval(*this, this->impl->ctx, std::move(params), [](auto&, auto f) { return f(); });
 }
 
 double common_average(const std::vector<double>& v)

src/targets/cpu/cpu_lowering.cpp

@@ -7,6 +7,7 @@
 #include <migraph/iterator_for.hpp>
 #include <migraph/cpu/gemm.hpp>
 #include <unordered_map>
+#include <utility>
 
 namespace migraph {
 namespace cpu {
@@ -39,9 +40,9 @@ struct cpu_batch_norm_inference
 
     std::string name() const { return "cpu::batch_norm_inference"; }
 
-    shape compute_shape(std::vector<shape> inputs) const { return op.compute_shape(inputs); }
+    shape compute_shape(const std::vector<shape>& inputs) const { return op.compute_shape(inputs); }
 
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument output{output_shape};
 
@@ -95,7 +96,7 @@ struct cpu_convolution
     convolution op;
 
     std::string name() const { return "cpu::convolution"; }
-    shape compute_shape(std::vector<shape> inputs) const { return op.compute_shape(inputs); }
+    shape compute_shape(const std::vector<shape>& inputs) const { return op.compute_shape(inputs); }
     argument compute(context&, shape output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
@@ -161,8 +162,8 @@ struct cpu_pooling
     pooling op;
 
     std::string name() const { return "cpu::pooling_" + Op::name(); }
-    shape compute_shape(std::vector<shape> inputs) const { return op.compute_shape(inputs); }
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    shape compute_shape(const std::vector<shape>& inputs) const { return op.compute_shape(inputs); }
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
         visit_all(result, args[0])([&](auto output, auto input) {
@@ -208,8 +209,8 @@ struct cpu_contiguous
 {
     contiguous op;
     std::string name() const { return "cpu::contiguous"; }
-    shape compute_shape(std::vector<shape> inputs) const { return op.compute_shape(inputs); }
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    shape compute_shape(const std::vector<shape>& inputs) const { return op.compute_shape(inputs); }
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
         visit_all(result, args[0])([&](auto output, auto input) {
@@ -225,9 +226,9 @@ struct cpu_gemm
 {
     gemm op;
     std::string name() const { return "cpu::gemm"; }
-    shape compute_shape(std::vector<shape> inputs) const { return op.compute_shape(inputs); }
+    shape compute_shape(const std::vector<shape>& inputs) const { return op.compute_shape(inputs); }
 
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
         migemm(result, args[0], args[1], op.alpha, op.beta);
@@ -357,8 +358,8 @@ struct cpu_unary
 {
     Op op;
     std::string name() const { return op.name(); }
-    shape compute_shape(std::vector<shape> inputs) const { return inputs.front(); }
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    shape compute_shape(const std::vector<shape>& inputs) const { return inputs.front(); }
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
         result.visit([&](auto output) {
@@ -373,8 +374,8 @@ struct cpu_unary
 struct softmax2d
 {
     std::string name() const { return "cpu::softmax2d"; }
-    shape compute_shape(std::vector<shape> inputs) const { return inputs.front(); }
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    shape compute_shape(const std::vector<shape>& inputs) const { return inputs.front(); }
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
         visit_all(result, args[0])([&](auto output, auto input) {
@@ -449,8 +450,8 @@ struct cpu_binary
 {
     Op op;
     std::string name() const { return op.name(); }
-    shape compute_shape(std::vector<shape> inputs) const { return inputs.front(); }
-    argument compute(context&, shape output_shape, std::vector<argument> args) const
+    shape compute_shape(const std::vector<shape>& inputs) const { return inputs.front(); }
+    argument compute(context&, const shape& output_shape, std::vector<argument> args) const
     {
         argument result{output_shape};
         visit_all(result, args[0], args[1])([&](auto output, auto input1, auto input2) {

src/targets/gpu/hip.cpp

@@ -65,7 +65,7 @@ hip_ptr write_to_gpu(const void* x, std::size_t sz, bool host = false)
     return result;
 }
 
-argument allocate_gpu(shape s, bool host)
+argument allocate_gpu(const shape& s, bool host)
 {
     auto p = share(allocate_gpu(s.bytes() + 1, host));
     return {s, [p]() mutable { return reinterpret_cast<char*>(p.get()); }};