1 # atomic builtins are required for threading support. 2 3 INCLUDE(CheckCXXSourceCompiles) 4 5 CHECK_CXX_SOURCE_COMPILES(" 6 #ifdef _MSC_VER 7 #include <windows.h> 8 #endif 9 int main() { 10 #ifdef _MSC_VER 11 volatile LONG val = 1; 12 MemoryBarrier(); 13 InterlockedCompareExchange(&val, 0, 1); 14 InterlockedIncrement(&val); 15 InterlockedDecrement(&val); 16 #else 17 volatile unsigned long val = 1; 18 __sync_synchronize(); 19 __sync_val_compare_and_swap(&val, 1, 0); 20 __sync_add_and_fetch(&val, 1); 21 __sync_sub_and_fetch(&val, 1); 22 #endif 23 return 0; 24 } 25 " LLVM_HAS_ATOMICS) 26 27 if( NOT LLVM_HAS_ATOMICS ) 28 message(STATUS "Warning: LLVM will be built thread-unsafe because atomic builtins are missing") 29 endif() 30
