Label the existing atomic functions as 32-bit specific, and add a 64-bit one that will be useful in
the near future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73971 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Atomic.cpp b/lib/System/Atomic.cpp
index 6e751a3..65e1469 100644
--- a/lib/System/Atomic.cpp
+++ b/lib/System/Atomic.cpp
@@ -35,11 +35,11 @@
 #endif
 }
 
-sys::cas_flag sys::CompareAndSwap(volatile sys::cas_flag* ptr,
-                                  sys::cas_flag new_value,
-                                  sys::cas_flag old_value) {
+uint32_t sys::CompareAndSwap32(volatile uint32_t* ptr,
+                               uint32_t new_value,
+                               uint32_t old_value) {
 #if LLVM_MULTITHREADED==0
-  sys::cas_flag result = *ptr;
+  uint32_t result = *ptr;
   if (result == old_value)
     *ptr = new_value;
   return result;
@@ -52,7 +52,7 @@
 #endif
 }
 
-sys::cas_flag sys::AtomicIncrement(volatile sys::cas_flag* ptr) {
+uint32_t sys::AtomicIncrement32(volatile uint32_t* ptr) {
 #if LLVM_MULTITHREADED==0
   ++(*ptr);
   return *ptr;
@@ -65,7 +65,7 @@
 #endif
 }
 
-sys::cas_flag sys::AtomicDecrement(volatile sys::cas_flag* ptr) {
+uint32_t sys::AtomicDecrement32(volatile uint32_t* ptr) {
 #if LLVM_MULTITHREADED==0
   --(*ptr);
   return *ptr;
@@ -78,7 +78,7 @@
 #endif
 }
 
-sys::cas_flag sys::AtomicAdd(volatile sys::cas_flag* ptr, sys::cas_flag val) {
+uint32_t sys::AtomicAdd32(volatile uint32_t* ptr, uint32_t val) {
 #if LLVM_MULTITHREADED==0
   *ptr += val;
   return *ptr;
@@ -91,4 +91,16 @@
 #endif
 }
 
+uint64_t sys::AtomicAdd64(volatile uint64_t* ptr, uint64_t val) {
+#if LLVM_MULTITHREADED==0
+  *ptr += val;
+  return *ptr;
+#elif defined(__GNUC__)
+  return __sync_add_and_fetch(ptr, val);
+#elif defined(_MSC_VER)
+  return InterlockedAdd64(ptr, val);
+#else
+#  error No atomic add implementation for your platform!
+#endif
+}