[OpenMP] Add explicit attributes to every function declaration

offload/DeviceRTL/CMakeLists.txt

@@ -98,7 +98,7 @@ list(TRANSFORM LIBOMPTARGET_LLVM_INCLUDE_DIRS_DEVICERTL PREPEND "-I")
 set(bc_flags -c -foffload-lto -std=c++17 -fvisibility=hidden
               ${clang_opt_flags} --offload-device-only
              -nocudalib -nogpulib -nogpuinc -nostdlibinc
-             -fopenmp -fopenmp-cuda-mode
+             -fopenmp -fopenmp-cuda-mode -Wno-unknown-assumption
              -Wno-unknown-cuda-version -Wno-openmp-target
              -DOMPTARGET_DEVICE_RUNTIME
              -I${include_directory}

offload/DeviceRTL/include/Allocator.h

@@ -26,22 +26,23 @@ namespace allocator {
 static uint64_t constexpr ALIGNMENT = 16;
 
 /// Initialize the allocator according to \p KernelEnvironment
-void init(bool IsSPMD, KernelEnvironmentTy &KernelEnvironment);
+OMP_ATTRS void init(bool IsSPMD, KernelEnvironmentTy &KernelEnvironment);
 
 /// Allocate \p Size bytes.
-[[gnu::alloc_size(1), gnu::assume_aligned(ALIGNMENT), gnu::malloc]] void *
+[[gnu::alloc_size(1), gnu::assume_aligned(ALIGNMENT),
+  gnu::malloc]] OMP_ATTRS void *
 alloc(uint64_t Size);
 
 /// Free the allocation pointed to by \p Ptr.
-void free(void *Ptr);
+OMP_ATTRS void free(void *Ptr);
 
 } // namespace allocator
 
 } // namespace ompx
 
 extern "C" {
-[[gnu::weak]] void *malloc(size_t Size);
-[[gnu::weak]] void free(void *Ptr);
+[[gnu::weak]] OMP_ATTRS void *malloc(size_t Size);
+[[gnu::weak]] OMP_ATTRS void free(void *Ptr);
 }
 
 #pragma omp end declare target

offload/DeviceRTL/include/Configuration.h

@@ -22,45 +22,45 @@ namespace config {
 
 /// Return the number of devices in the system, same number as returned on the
 /// host by omp_get_num_devices.
-uint32_t getNumDevices();
+OMP_ATTRS uint32_t getNumDevices();
 
 /// Return the device number in the system for omp_get_device_num.
-uint32_t getDeviceNum();
+OMP_ATTRS uint32_t getDeviceNum();
 
 /// Return the user choosen debug level.
-uint32_t getDebugKind();
+OMP_ATTRS uint32_t getDebugKind();
 
 /// Return if teams oversubscription is assumed
-uint32_t getAssumeTeamsOversubscription();
+OMP_ATTRS uint32_t getAssumeTeamsOversubscription();
 
 /// Return if threads oversubscription is assumed
-uint32_t getAssumeThreadsOversubscription();
+OMP_ATTRS uint32_t getAssumeThreadsOversubscription();
 
 /// Return the amount of dynamic shared memory that was allocated at launch.
-uint64_t getDynamicMemorySize();
+OMP_ATTRS uint64_t getDynamicMemorySize();
 
 /// Returns the cycles per second of the device's fixed frequency clock.
-uint64_t getClockFrequency();
+OMP_ATTRS uint64_t getClockFrequency();
 
 /// Returns the pointer to the beginning of the indirect call table.
-void *getIndirectCallTablePtr();
+OMP_ATTRS void *getIndirectCallTablePtr();
 
 /// Returns the size of the indirect call table.
-uint64_t getIndirectCallTableSize();
+OMP_ATTRS uint64_t getIndirectCallTableSize();
 
 /// Returns the size of the indirect call table.
-uint64_t getHardwareParallelism();
+OMP_ATTRS uint64_t getHardwareParallelism();
 
 /// Return if debugging is enabled for the given debug kind.
-bool isDebugMode(DeviceDebugKind Level);
+OMP_ATTRS bool isDebugMode(DeviceDebugKind Level);
 
 /// Indicates if this kernel may require thread-specific states, or if it was
 /// explicitly disabled by the user.
-bool mayUseThreadStates();
+OMP_ATTRS bool mayUseThreadStates();
 
 /// Indicates if this kernel may require data environments for nested
 /// parallelism, or if it was explicitly disabled by the user.
-bool mayUseNestedParallelism();
+OMP_ATTRS bool mayUseNestedParallelism();
 
 } // namespace config
 } // namespace ompx

offload/DeviceRTL/include/Debug.h

@@ -19,11 +19,12 @@
 ///
 /// {
 extern "C" {
-void __assert_assume(bool condition);
-void __assert_fail(const char *expr, const char *file, unsigned line,
-                   const char *function);
-void __assert_fail_internal(const char *expr, const char *msg, const char *file,
-                            unsigned line, const char *function);
+OMP_ATTRS void __assert_assume(bool condition);
+OMP_ATTRS void __assert_fail(const char *expr, const char *file, unsigned line,
+                             const char *function);
+OMP_ATTRS void __assert_fail_internal(const char *expr, const char *msg,
+                                      const char *file, unsigned line,
+                                      const char *function);
 }
 
 #define ASSERT(expr, msg)                                                      \

offload/DeviceRTL/include/DeviceTypes.h

@@ -20,9 +20,7 @@
 // another function but only inline assembly that performs some operation or
 // side-effect and then continues execution with something on the existing call
 // stack.
-//
-// TODO: Find a good place for this
-#pragma omp assumes ext_no_call_asm
+#define OMP_ATTRS [[omp::assume("ext_no_call_asm"), gnu::visibility("hidden")]]
 
 enum omp_proc_bind_t {
   omp_proc_bind_false = 0,

offload/DeviceRTL/include/DeviceUtils.h

@@ -60,32 +60,35 @@ struct remove_addrspace<T [[clang::address_space(N)]]> : type_identity<T> {};
 template <class T>
 using remove_addrspace_t = typename remove_addrspace<T>::type;
 
-template <typename To, typename From> inline To bitCast(From V) {
+template <typename To, typename From> OMP_ATTRS inline To bitCast(From V) {
   static_assert(sizeof(To) == sizeof(From), "Bad conversion");
   return __builtin_bit_cast(To, V);
 }
 
 /// Return the value \p Var from thread Id \p SrcLane in the warp if the thread
 /// is identified by \p Mask.
-int32_t shuffle(uint64_t Mask, int32_t Var, int32_t SrcLane, int32_t Width);
+OMP_ATTRS int32_t shuffle(uint64_t Mask, int32_t Var, int32_t SrcLane,
+                          int32_t Width);
 
-int32_t shuffleDown(uint64_t Mask, int32_t Var, uint32_t Delta, int32_t Width);
+OMP_ATTRS int32_t shuffleDown(uint64_t Mask, int32_t Var, uint32_t Delta,
+                              int32_t Width);
 
-int64_t shuffleDown(uint64_t Mask, int64_t Var, uint32_t Delta, int32_t Width);
+OMP_ATTRS int64_t shuffleDown(uint64_t Mask, int64_t Var, uint32_t Delta,
+                              int32_t Width);
 
-uint64_t ballotSync(uint64_t Mask, int32_t Pred);
+OMP_ATTRS uint64_t ballotSync(uint64_t Mask, int32_t Pred);
 
 /// Return \p LowBits and \p HighBits packed into a single 64 bit value.
-uint64_t pack(uint32_t LowBits, uint32_t HighBits);
+OMP_ATTRS uint64_t pack(uint32_t LowBits, uint32_t HighBits);
 
 /// Unpack \p Val into \p LowBits and \p HighBits.
-void unpack(uint64_t Val, uint32_t &LowBits, uint32_t &HighBits);
+OMP_ATTRS void unpack(uint64_t Val, uint32_t &LowBits, uint32_t &HighBits);
 
 /// Return true iff \p Ptr is pointing into shared (local) memory (AS(3)).
-bool isSharedMemPtr(void *Ptr);
+OMP_ATTRS bool isSharedMemPtr(void *Ptr);
 
 /// Return true iff \p Ptr is pointing into (thread) local memory (AS(5)).
-bool isThreadLocalMemPtr(void *Ptr);
+OMP_ATTRS bool isThreadLocalMemPtr(void *Ptr);
 
 /// A  pointer variable that has by design an `undef` value. Use with care.
 [[clang::loader_uninitialized]] static void *const UndefPtr;