[C++11] Replace LLVM atomics with std::atomic.

With C++11 we finally have a standardized way to specify atomic operations. Use
them to replace the existing custom implemention. Sadly the translation is not
entirely trivial as std::atomic allows more fine-grained control over the
atomicity. I tried to preserve the old semantics as well as possible.

Differential Revision: http://llvm-reviews.chandlerc.com/D2915

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202730 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 3 insertions, 4 deletions

diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 9d9d948527..24cd6c7c1a 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -18,7 +18,6 @@
 #include "LLVMContextImpl.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/Type.h"
-#include "llvm/Support/Atomic.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Mutex.h"
diff --git a/lib/IR/DiagnosticInfo.cpp b/lib/IR/DiagnosticInfo.cpp
index 86e8788eb0..75ddd94b35 100644
--- a/lib/IR/DiagnosticInfo.cpp
+++ b/lib/IR/DiagnosticInfo.cpp
@@ -19,14 +19,14 @@
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Metadata.h"
-#include "llvm/Support/Atomic.h"
+#include <atomic>
 #include <string>
 
 using namespace llvm;
 
 int llvm::getNextAvailablePluginDiagnosticKind() {
-  static sys::cas_flag PluginKindID = DK_FirstPluginKind;
-  return (int)sys::AtomicIncrement(&PluginKindID);
+  static std::atomic<int> PluginKindID(DK_FirstPluginKind);
+  return ++PluginKindID;
 }
 
 DiagnosticInfoInlineAsm::DiagnosticInfoInlineAsm(const Instruction &I,