vendor/clang/clang-trunk-r351319

1 files changed, 19 insertions, 9 deletions

diff --git a/lib/CodeGen/CGAtomic.cpp b/lib/CodeGen/CGAtomic.cpp
index b34bcdc1fc38d..24056a449def4 100644
--- a/lib/CodeGen/CGAtomic.cpp
+++ b/lib/CodeGen/CGAtomic.cpp
@@ -18,7 +18,7 @@
 #include "TargetInfo.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
-#include "clang/Sema/SemaDiagnostic.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Intrinsics.h"
@@ -765,11 +765,15 @@ RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E) {
   std::tie(sizeChars, alignChars) = getContext().getTypeInfoInChars(AtomicTy);
   uint64_t Size = sizeChars.getQuantity();
   unsigned MaxInlineWidthInBits = getTarget().getMaxAtomicInlineWidth();
-  bool UseLibcall = ((Ptr.getAlignment() % sizeChars) != 0 ||
-                     getContext().toBits(sizeChars) > MaxInlineWidthInBits);
 
-  if (UseLibcall)
-    CGM.getDiags().Report(E->getLocStart(), diag::warn_atomic_op_misaligned);
+  bool Oversized = getContext().toBits(sizeChars) > MaxInlineWidthInBits;
+  bool Misaligned = (Ptr.getAlignment() % sizeChars) != 0;
+  bool UseLibcall = Misaligned | Oversized;
+
+  if (UseLibcall) {
+    CGM.getDiags().Report(E->getBeginLoc(), diag::warn_atomic_op_misaligned)
+        << !Oversized;
+  }
 
   llvm::Value *Order = EmitScalarExpr(E->getOrder());
   llvm::Value *Scope =
@@ -923,6 +927,15 @@ RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E) {
       UseOptimizedLibcall = true;
       break;
 
+    case AtomicExpr::AO__atomic_load:
+    case AtomicExpr::AO__atomic_store:
+    case AtomicExpr::AO__atomic_exchange:
+    case AtomicExpr::AO__atomic_compare_exchange:
+      // Use the generic version if we don't know that the operand will be
+      // suitably aligned for the optimized version.
+      if (Misaligned)
+        break;
+      LLVM_FALLTHROUGH;
     case AtomicExpr::AO__c11_atomic_load:
     case AtomicExpr::AO__c11_atomic_store:
     case AtomicExpr::AO__c11_atomic_exchange:
@@ -934,14 +947,11 @@ RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E) {
     case AtomicExpr::AO__opencl_atomic_compare_exchange_weak:
     case AtomicExpr::AO__opencl_atomic_compare_exchange_strong:
     case AtomicExpr::AO__atomic_load_n:
-    case AtomicExpr::AO__atomic_load:
     case AtomicExpr::AO__atomic_store_n:
-    case AtomicExpr::AO__atomic_store:
     case AtomicExpr::AO__atomic_exchange_n:
-    case AtomicExpr::AO__atomic_exchange:
     case AtomicExpr::AO__atomic_compare_exchange_n:
-    case AtomicExpr::AO__atomic_compare_exchange:
       // Only use optimized library calls for sizes for which they exist.
+      // FIXME: Size == 16 optimized library functions exist too.
       if (Size == 1 || Size == 2 || Size == 4 || Size == 8)
         UseOptimizedLibcall = true;
       break;