Use Pimpl idiom for LookupBackend

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.16)
 project(trigdx LANGUAGES CXX)
 
-set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 option(USE_MKL "Enable Intel MKL backend" OFF)

include/trigdx/lookup.hpp

@@ -1,12 +1,15 @@
 #pragma once
 
-#include <cmath>
+#include <cstddef>
-#include <vector>
+#include <memory>
 
 #include "interface.hpp"
 
 template <size_t NR_SAMPLES> class LookupBackend : public Backend {
 public:
+  LookupBackend();
+  ~LookupBackend() override;
+
   void init() override;
   void compute_sinf(size_t n, const float *x, float *s) const override;
   void compute_cosf(size_t n, const float *x, float *c) const override;
@@ -14,9 +17,6 @@ public:
                        float *c) const override;
 
 private:
-  std::vector<float> lookup;
+  struct Impl;
-  static constexpr size_t MASK = NR_SAMPLES - 1;
+  std::unique_ptr<Impl> impl;
-  static constexpr float SCALE = NR_SAMPLES / (2.0f * float(M_PI));
 };
-
-#include "lookup.tpp" // include implementation

include/trigdx/lookup.tpp

@@ -1,44 +0,0 @@
-#pragma once
-
-#include <cmath>
-
-template <size_t NR_SAMPLES>
-void LookupBackend<NR_SAMPLES>::init() {
-    lookup.resize(NR_SAMPLES);
-    for (size_t i = 0; i < NR_SAMPLES; ++i)
-        lookup[i] = std::sinf(i * (2.0f * float(M_PI) / NR_SAMPLES));
-}
-
-template <size_t NR_SAMPLES>
-void LookupBackend<NR_SAMPLES>::compute_sinf(size_t n,
-                                               const float* x,
-                                               float* s) const {
-    for (size_t i = 0; i < n; ++i) {
-        size_t idx = static_cast<size_t>(x[i] * SCALE) & MASK;
-        s[i] = lookup[idx];
-    }
-}
-
-template <size_t NR_SAMPLES>
-void LookupBackend<NR_SAMPLES>::compute_cosf(size_t n,
-                                               const float* x,
-                                               float* c) const {
-    for (size_t i = 0; i < n; ++i) {
-        size_t idx = static_cast<size_t>(x[i] * SCALE) & MASK;
-        size_t idx_cos = (idx + NR_SAMPLES / 4) & MASK;
-        c[i] = lookup[idx_cos];
-    }
-}
-
-template <size_t NR_SAMPLES>
-void LookupBackend<NR_SAMPLES>::compute_sincosf(size_t n,
-                                                  const float* x,
-                                                  float* s,
-                                                  float* c) const {
-    for (size_t i = 0; i < n; ++i) {
-        size_t idx = static_cast<size_t>(x[i] * SCALE) & MASK;
-        size_t idx_cos = (idx + NR_SAMPLES / 4) & MASK;
-        s[i] = lookup[idx];
-        c[i] = lookup[idx_cos];
-    }
-}

src/CMakeLists.txt

@@ -1,4 +1,4 @@
-add_library(trigdx reference.cpp)
+add_library(trigdx reference.cpp lookup.cpp)
 
 target_include_directories(trigdx PUBLIC ${PROJECT_SOURCE_DIR}/include)
 

src/lookup.cpp

@@ -0,0 +1,72 @@
+#include <cmath>
+#include <memory>
+#include <vector>
+
+#include "trigdx/lookup.hpp"
+
+template <size_t NR_SAMPLES> struct LookupBackend<NR_SAMPLES>::Impl {
+  std::vector<float> lookup;
+  static constexpr size_t MASK = NR_SAMPLES - 1;
+  static constexpr float SCALE = NR_SAMPLES / (2.0f * float(M_PI));
+
+  void init() {
+    lookup.resize(NR_SAMPLES);
+    for (size_t i = 0; i < NR_SAMPLES; ++i)
+      lookup[i] = std::sinf(i * (2.0f * float(M_PI) / NR_SAMPLES));
+  }
+
+  void compute_sinf(size_t n, const float *x, float *s) const {
+    for (size_t i = 0; i < n; ++i) {
+      size_t idx = static_cast<size_t>(x[i] * SCALE) & MASK;
+      s[i] = lookup[idx];
+    }
+  }
+
+  void compute_cosf(size_t n, const float *x, float *c) const {
+    for (size_t i = 0; i < n; ++i) {
+      size_t idx = static_cast<size_t>(x[i] * SCALE) & MASK;
+      size_t idx_cos = (idx + NR_SAMPLES / 4) & MASK;
+      c[i] = lookup[idx_cos];
+    }
+  }
+
+  void compute_sincosf(size_t n, const float *x, float *s, float *c) const {
+    for (size_t i = 0; i < n; ++i) {
+      size_t idx = static_cast<size_t>(x[i] * SCALE) & MASK;
+      size_t idx_cos = (idx + NR_SAMPLES / 4) & MASK;
+      s[i] = lookup[idx];
+      c[i] = lookup[idx_cos];
+    }
+  }
+};
+
+template <size_t NR_SAMPLES>
+LookupBackend<NR_SAMPLES>::LookupBackend() : impl(std::make_unique<Impl>()) {}
+
+template <size_t NR_SAMPLES>
+LookupBackend<NR_SAMPLES>::~LookupBackend() = default;
+
+template <size_t NR_SAMPLES> void LookupBackend<NR_SAMPLES>::init() {
+  impl->init();
+}
+
+template <size_t NR_SAMPLES>
+void LookupBackend<NR_SAMPLES>::compute_sinf(size_t n, const float *x,
+                                             float *s) const {
+  impl->compute_sinf(n, x, s);
+}
+
+template <size_t NR_SAMPLES>
+void LookupBackend<NR_SAMPLES>::compute_cosf(size_t n, const float *x,
+                                             float *c) const {
+  impl->compute_cosf(n, x, c);
+}
+
+template <size_t NR_SAMPLES>
+void LookupBackend<NR_SAMPLES>::compute_sincosf(size_t n, const float *x,
+                                                float *s, float *c) const {
+  impl->compute_sincosf(n, x, s, c);
+}
+
+template class LookupBackend<16384>;
+template class LookupBackend<32768>;