Switching to C++17 (if constexpr support), full support for invalid n…

…umeric_types
bkj · Oct 28, 2020 · 2aa9447 · 2aa9447
1 parent 08918f2
commit 2aa9447
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Showing 6 changed files with 46 additions and 40 deletions.
diff --git a/examples/Makefile.inc b/examples/Makefile.inc
@@ -67,11 +67,11 @@ DEFINES 	= -DGIT_SHA1="\"$(shell git rev-parse HEAD)\""
 # 	ARCH = -m64
 # endif
 
-NVCCFLAGS   += -std=c++14
+NVCCFLAGS   += -std=c++17
 NVCCFLAGS   += $(SM_TARGETS)
 NVCCFLAGS   += --expt-extended-lambda --expt-relaxed-constexpr --use_fast_math --ptxas-options -v --relocatable-device-code true
 
-CXXFLAGS    += -std=c++14
+CXXFLAGS    += -std=c++17
 CXXFLAGS    += -Wall
 CXXFLAGS    += -Wno-unused-local-typedefs -Wno-strict-aliasing -Wno-unused-function -Wno-format-security
 

diff --git a/gunrock/graph/graph.hxx b/gunrock/graph/graph.hxx
@@ -135,7 +135,7 @@ class graph_t : public graph_view_t... {
   }
 
   __host__ __device__ __forceinline__ edge_type
-  get_starting_edge(vertex_type const& v) const {
+  get_starting_edge(vertex_type const& v) const override {
     return first_view_t::get_starting_edge(v);
   }
 

diff --git a/gunrock/util/type_limits.hxx b/gunrock/util/type_limits.hxx
@@ -13,36 +13,40 @@
 
 namespace gunrock {
 
-template <typename type_t>
+template <typename type_t, typename enable_t = void>
 struct numeric_limits : std::numeric_limits<type_t> {};
 
 // Numeric Limits (additional support) for invalid() values.
-template <>
-struct numeric_limits<int> : std::numeric_limits<int> {
-  // XXX: This doesn't seem like the right thing to do for a signed integral
-  // type. It implies, -1 is an invalid value. Integers do not have a notion of
-  // invalid values.
-  constexpr static int invalid() { return ~((int)0); }
-};
-
-template <>
-struct numeric_limits<float> : std::numeric_limits<float> {
-  constexpr static float invalid() {
-    return std::numeric_limits<float>::quiet_NaN();
+template <typename type_t>
+struct numeric_limits<
+    type_t,
+    typename std::enable_if_t<std::is_integral<type_t>::value &&
+                              std::is_signed<type_t>::value>>
+    : std::numeric_limits<type_t> {
+  constexpr static type_t invalid() {
+    return std::integral_constant<type_t, -1>::value;
   }
 };
 
-template <>
-struct numeric_limits<double> : std::numeric_limits<double> {
-  constexpr static double invalid() {
-    return std::numeric_limits<double>::quiet_NaN();
+template <typename type_t>
+struct numeric_limits<
+    type_t,
+    typename std::enable_if_t<std::is_integral<type_t>::value &&
+                              std::is_unsigned<type_t>::value>>
+    : std::numeric_limits<type_t> {
+  constexpr static type_t invalid() {
+    return std::integral_constant<type_t,
+                                  std::numeric_limits<type_t>::max()>::value;
   }
 };
 
-template <>
-struct numeric_limits<long double> : std::numeric_limits<long double> {
-  constexpr static long double invalid() {
-    return std::numeric_limits<long double>::quiet_NaN();
+template <typename type_t>
+struct numeric_limits<
+    type_t,
+    typename std::enable_if_t<std::is_floating_point<type_t>::value>>
+    : std::numeric_limits<type_t> {
+  constexpr static type_t invalid() {
+    return std::numeric_limits<type_t>::quiet_NaN();
   }
 };
 
@@ -52,17 +56,16 @@ namespace gunrock {
 namespace util {
 namespace limits {
 
-// XXX: Revisit later...
-template <typename numeric_t>
-__host__ __device__ __forceinline__ bool is_valid(numeric_t const& value) {
-  static_assert(std::is_arithmetic_v<numeric_t>);
-  return !isnan(value);
-}
-
-template <typename numeric_t>
-__host__ __device__ __forceinline__ bool is_invalid(numeric_t const& value) {
-  static_assert(std::is_arithmetic_v<numeric_t>);
-  return isnan(value);
+template <typename type_t>
+__host__ __device__ __forceinline__ bool is_valid(type_t value) {
+  static_assert((std::is_integral<type_t>::value ||
+                 std::is_floating_point<type_t>::value),
+                "type_t must be an arithmetic type.");
+  if constexpr (std::is_integral<type_t>::value)
+    return (value != gunrock::numeric_limits<type_t>::invalid());
+  else
+    // XXX: test this on device
+    return (bool)!isnan(value);
 }
 
 }  // namespace limits

diff --git a/gunrock/util/type_traits.hxx b/gunrock/util/type_traits.hxx
@@ -4,6 +4,7 @@
 
 namespace std {
 
+#if __cplusplus == 201402L
 // Supported in C++ 17 (https://en.cppreference.com/w/cpp/types/disjunction)
 template <class...>
 struct disjunction : std::false_type {};
@@ -25,4 +26,5 @@ constexpr bool is_arithmetic_v = is_arithmetic<T>::value;
 // (https://en.cppreference.com/w/cpp/types/is_floating_point)
 template <class T>
 constexpr bool is_floating_point_v = is_floating_point<T>::value;
+#endif
 }  // namespace std
diff --git a/unittests/Makefile.inc b/unittests/Makefile.inc
@@ -67,11 +67,11 @@ DEFINES 	= -DGIT_SHA1="\"$(shell git rev-parse HEAD)\""
 # 	ARCH = -m64
 # endif
 
-NVCCFLAGS   += -std=c++14
+NVCCFLAGS   += -std=c++17
 NVCCFLAGS   += $(SM_TARGETS)
 NVCCFLAGS   += --expt-extended-lambda --expt-relaxed-constexpr --use_fast_math --ptxas-options -v --relocatable-device-code true
 
-CXXFLAGS    += -std=c++14
+CXXFLAGS    += -std=c++17
 CXXFLAGS    += -Wall
 CXXFLAGS    += -Wno-unused-local-typedefs -Wno-strict-aliasing -Wno-unused-function -Wno-format-security
 

diff --git a/unittests/type_limits/test_type_limits.cu b/unittests/type_limits/test_type_limits.cu
@@ -4,9 +4,10 @@
 #include <gunrock/util/type_limits.hxx>
 
 void test_type_limits() {
-  float i = gunrock::numeric_limits<float>::invalid();
-  std::cout << i << " is valid? " << std::boolalpha
-            << gunrock::util::limits::is_valid(i) << std::endl;
+  using type_t = short unsigned int;
+  type_t i = gunrock::numeric_limits<type_t>::invalid();
+  std::cout << "i = " << i << " (is valid? " << std::boolalpha
+            << gunrock::util::limits::is_valid(i) << ")" << std::endl;
 }
 
 int main(int argc, char** argv) {