From b0310dcff11cade76add2b84f9d694fc626284ee Mon Sep 17 00:00:00 2001 From: Khem Raj Date: Mon, 18 Nov 2019 17:00:29 -0800 Subject: [PATCH] Check for atomic intrinsics On some architectures e.g. x86/32bit gcc decides to inline calls to double atomic variables but clang does not and defers it to libatomic therefore detect if clang can use built-ins for atomic if not then link libatomic, this helps building clangd for x86 on linux systems with gcc runtime Upstream-Status: Pending Signed-off-by: Khem Raj --- llvm/cmake/modules/CheckAtomic.cmake | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/llvm/cmake/modules/CheckAtomic.cmake b/llvm/cmake/modules/CheckAtomic.cmake index f11cadf39ff6..80a18a92956a 100644 --- a/llvm/cmake/modules/CheckAtomic.cmake +++ b/llvm/cmake/modules/CheckAtomic.cmake @@ -30,10 +30,11 @@ function(check_working_cxx_atomics64 varname) #include #include std::atomic x (0); +std::atomic y (0); int main() { uint64_t i = x.load(std::memory_order_relaxed); (void)i; - return 0; + return int(y); } " ${varname}) set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})