Make nvhpc math abide IEEE standard

CMakeLists.txt

@@ -121,9 +121,13 @@ endif()
 
 # For now, PGI/NVHPC nvc++ compiler doesn't seem to support
 # `#pragma omp declare reduction`
-if (${CMAKE_CXX_COMPILER_ID} MATCHES "PGI|NVHPC")
+#
+# The math with optimization level -O2 doesn't follow IEEE standard, so we
+# enable that back as well.
+if (CMAKE_CXX_COMPILER_ID MATCHES "PGI|NVHPC")
     message(STATUS "OpenMP: Switching to OFF because PGI/NVHPC nvc++ compiler lacks important features.")
     set(GINKGO_BUILD_OMP OFF)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Kieee")
 endif()
 
 set(GINKGO_CIRCULAR_DEPS_FLAGS "-Wl,--no-undefined")

include/ginkgo/core/base/std_extensions.hpp

@@ -70,7 +70,7 @@ template <typename... Ts>
 using void_t = typename detail::make_void<Ts...>::type;
 
 
-// Disable deprecation warnings when using standard > 2014
+// Disable deprecation warnings when using standard > C++14
 inline bool uncaught_exception() noexcept {
 #if __cplusplus > 201402L
     return std::uncaught_exceptions() > 0;