Merge pull request #108 from NVIDIA/more-const-init

Added constexpr to synchronization object constructors

Author: ogiroux

include/cuda/std/barrier

@@ -48,7 +48,7 @@ public:
     barrier(const barrier &) = delete;
     barrier & operator=(const barrier &) = delete;
 
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     barrier(std::ptrdiff_t __expected, _CompletionF __completion = _CompletionF())
         : std::__barrier_base<_CompletionF, _Sco>(__expected, __completion) {
     }

include/cuda/std/latch

@@ -27,7 +27,7 @@ _LIBCUDACXX_BEGIN_NAMESPACE_CUDA
 template<thread_scope _Sco>
 class latch : public std::__latch_base<_Sco> {
 public:
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     latch(std::ptrdiff_t __count)
         : std::__latch_base<_Sco>(__count) {
     }

include/cuda/std/semaphore

@@ -29,7 +29,7 @@ class counting_semaphore : public std::__semaphore_base<__least_max_value, _Sco>
 {
     static_assert(__least_max_value <= std::__semaphore_base<__least_max_value, _Sco>::max(), "");
 public:
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     counting_semaphore(ptrdiff_t __count = 0) : std::__semaphore_base<__least_max_value, _Sco>(__count) { }
     ~counting_semaphore() = default;
 

libcxx/include/barrier

@@ -302,8 +302,8 @@ private:
         }
     };
 
-    static inline _LIBCUDACXX_INLINE_VISIBILITY
-    constexpr uint64_t __init(ptrdiff_t __count) _NOEXCEPT
+    static inline _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
+    uint64_t __init(ptrdiff_t __count) _NOEXCEPT
     {
         return (((1u << 31) - __count) << 32)
               | ((1u << 31) - __count);
@@ -312,7 +312,7 @@ private:
 public:
     __barrier_base() = default;
 
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     __barrier_base(ptrdiff_t __count, __empty_completion = __empty_completion())
         : __phase_arrived_expected(__init(__count)) {
     }
@@ -369,7 +369,7 @@ public:
 template<class _CompletionF = __empty_completion>
 class barrier : public __barrier_base<_CompletionF> {
 public:
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     barrier(ptrdiff_t __count, _CompletionF __completion = _CompletionF())
         : __barrier_base<_CompletionF>(__count, __completion) {
     }

libcxx/include/latch

@@ -71,8 +71,8 @@ class __latch_base
 {
     _LIBCUDACXX_LATCH_ALIGNMENT __atomic_base<ptrdiff_t, _Sco> __counter;
 public:
-    inline _LIBCUDACXX_INLINE_VISIBILITY
-    constexpr explicit __latch_base(ptrdiff_t __expected)
+    inline _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
+    explicit __latch_base(ptrdiff_t __expected)
         : __counter(__expected) { }
 
     ~__latch_base() = default;

libcxx/include/semaphore

@@ -119,8 +119,8 @@ public:
         return numeric_limits<ptrdiff_t>::max();
     }
 
-    _LIBCUDACXX_INLINE_VISIBILITY
-    __atomic_semaphore_base(ptrdiff_t __count) : __count(__count) { }
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
+    __atomic_semaphore_base(ptrdiff_t __count) noexcept : __count(__count) { }
 
     ~__atomic_semaphore_base() = default;
 
@@ -190,7 +190,7 @@ public:
     _LIBCUDACXX_INLINE_VISIBILITY
     static constexpr ptrdiff_t max() noexcept { return 1; }
 
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     __atomic_semaphore_base(ptrdiff_t __available) : __available(__available) { }
 
     ~__atomic_semaphore_base() = default;
@@ -428,7 +428,7 @@ class counting_semaphore : public __semaphore_base<__least_max_value, 0>
 {
     static_assert(__least_max_value <= __semaphore_base<__least_max_value, 0>::max(), "");
 public:
-    _LIBCUDACXX_INLINE_VISIBILITY
+    _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR
     counting_semaphore(ptrdiff_t __count = 0) : __semaphore_base<__least_max_value, 0>(__count) { }
     ~counting_semaphore() = default;