ARM: add support for v8 ldaex/stlex builtins.

ARMv8 adds (to both AArch32 and AArch64) acquiring and releasing
variants of the exclusive operations, in line with the C++11 memory
model.

This adds support for two new intrinsics to expose them to C & C++
developers directly: __builtin_arm_ldaex and __builtin_arm_stlex, in
direct analogy with the versions with no implicit barrier.

rdar://problem/15885451

llvm-svn: 212175
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index cd31f72..9fa8fd1 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -486,12 +486,18 @@
 bool Sema::CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
                                         unsigned MaxWidth) {
   assert((BuiltinID == ARM::BI__builtin_arm_ldrex ||
+          BuiltinID == ARM::BI__builtin_arm_ldaex ||
           BuiltinID == ARM::BI__builtin_arm_strex ||
+          BuiltinID == ARM::BI__builtin_arm_stlex ||
           BuiltinID == AArch64::BI__builtin_arm_ldrex ||
-          BuiltinID == AArch64::BI__builtin_arm_strex) &&
+          BuiltinID == AArch64::BI__builtin_arm_ldaex ||
+          BuiltinID == AArch64::BI__builtin_arm_strex ||
+          BuiltinID == AArch64::BI__builtin_arm_stlex) &&
          "unexpected ARM builtin");
   bool IsLdrex = BuiltinID == ARM::BI__builtin_arm_ldrex ||
-                 BuiltinID == AArch64::BI__builtin_arm_ldrex;
+                 BuiltinID == ARM::BI__builtin_arm_ldaex ||
+                 BuiltinID == AArch64::BI__builtin_arm_ldrex ||
+                 BuiltinID == AArch64::BI__builtin_arm_ldaex;
 
   DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
 
@@ -598,7 +604,9 @@
   llvm::APSInt Result;
 
   if (BuiltinID == ARM::BI__builtin_arm_ldrex ||
-      BuiltinID == ARM::BI__builtin_arm_strex) {
+      BuiltinID == ARM::BI__builtin_arm_ldaex ||
+      BuiltinID == ARM::BI__builtin_arm_strex ||
+      BuiltinID == ARM::BI__builtin_arm_stlex) {
     return CheckARMBuiltinExclusiveCall(BuiltinID, TheCall, 64);
   }
 
@@ -627,7 +635,9 @@
   llvm::APSInt Result;
 
   if (BuiltinID == AArch64::BI__builtin_arm_ldrex ||
-      BuiltinID == AArch64::BI__builtin_arm_strex) {
+      BuiltinID == AArch64::BI__builtin_arm_ldaex ||
+      BuiltinID == AArch64::BI__builtin_arm_strex ||
+      BuiltinID == AArch64::BI__builtin_arm_stlex) {
     return CheckARMBuiltinExclusiveCall(BuiltinID, TheCall, 128);
   }