fix spurious missing return statement

kokkos · Apr 14, 2023 · bb68066 · bb68066
1 parent 7e32d5c
commit bb68066
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Showing 3 changed files with 17 additions and 1 deletion.
diff --git a/common/src/KokkosKernels_ComparableCast.hpp b/common/src/KokkosKernels_ComparableCast.hpp
@@ -17,6 +17,8 @@
 #ifndef KOKKOSKERNELS_COMPARABLE_CAST_HPP
 #define KOKKOSKERNELS_COMPARABLE_CAST_HPP
 
+#include <Kokkos_Core.hpp>  // CUDA_VERSION
+
 namespace KokkosKernels {
 namespace Impl {
 
@@ -69,7 +71,7 @@ KOKKOS_INLINE_FUNCTION constexpr auto comparable_cast(const A &a) {
           std::is_signed_v<A> ? sizeof(A) : 2 * sizeof(A);
 
       // how wide to compare T and U
-      constexpr size_t width = std::max(t_width, a_width);
+      constexpr size_t width = KOKKOSKERNELS_MACRO_MAX(t_width, a_width);
       if constexpr (width == 1) {
         return int8_t(a);
       } else if constexpr (width == 2) {
@@ -91,6 +93,16 @@ KOKKOS_INLINE_FUNCTION constexpr auto comparable_cast(const A &a) {
       }
     }
   }
+
+  // CUDA 11 emits a spurious warning about a missing return statement.
+  // It is very hard to write an expression with a type that matches the
+  // result of the above, so mark as unreacable for the affected compiler
+  // instead
+#if defined(KOKKOS_ENABLE_CUDA)
+#if CUDA_VERSION >= 11030
+  __builting_unreachable();
+#endif
+#endif
 }
 
 }  // namespace Impl

diff --git a/common/unit_test/Test_Common_LowerBound.hpp b/common/unit_test/Test_Common_LowerBound.hpp
@@ -196,6 +196,8 @@ void test_lower_bound() {
     } else {
       return T(rand()) % n;
     }
+    // avoid CUDA 11 issuing a spurious missing return statement warning
+    return T(4);  // chosen by dice roll, guaranteed to be random
   };
 
   T maxEntry         = 20;

diff --git a/common/unit_test/Test_Common_UpperBound.hpp b/common/unit_test/Test_Common_UpperBound.hpp
@@ -185,6 +185,8 @@ void test_upper_bound() {
     } else {
       return T(rand()) % n;
     }
+    // avoid CUDA 11 issuing a spurious missing return statement warning
+    return T(4);  // chosen by dice roll, guaranteed to be random
   };
 
   constexpr T maxEntry = 20;