1 files changed, 56 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CGAtomic.cpp b/clang/lib/CodeGen/CGAtomic.cpp
index 927195083d4..a0b6073f6bf 100644
--- a/clang/lib/CodeGen/CGAtomic.cpp
+++ b/clang/lib/CodeGen/CGAtomic.cpp
@@ -1006,9 +1006,45 @@ RValue AtomicInfo::convertIntToValue(llvm::Value *IntVal,
   return convertTempToRValue(Temp, ResultSlot, Loc);
 }
 
+/// An LValue is a candidate for having its loads and stores be made atomic if
+/// we are operating under /volatile:ms *and* the LValue itself is volatile and
+/// performing such an operation can be performed without a libcall.
+bool CodeGenFunction::LValueIsSuitableForInlineAtomic(LValue LV) {
+  AtomicInfo AI(*this, LV);
+  bool IsVolatile = LV.isVolatile() || hasVolatileMember(LV.getType());
+  // An atomic is inline if we don't need to use a libcall.
+  bool AtomicIsInline = !AI.shouldUseLibcall();
+  return CGM.getCodeGenOpts().MSVolatile && IsVolatile && AtomicIsInline;
+}
+
+/// An type is a candidate for having its loads and stores be made atomic if
+/// we are operating under /volatile:ms *and* we know the access is volatile and
+/// performing such an operation can be performed without a libcall.
+bool CodeGenFunction::typeIsSuitableForInlineAtomic(QualType Ty,
+                                                    bool IsVolatile) const {
+  // An atomic is inline if we don't need to use a libcall (e.g. it is builtin).
+  bool AtomicIsInline = getContext().getTargetInfo().hasBuiltinAtomic(
+      getContext().getTypeSize(Ty), getContext().getTypeAlign(Ty));
+  return CGM.getCodeGenOpts().MSVolatile && IsVolatile && AtomicIsInline;
+}
+
+RValue CodeGenFunction::EmitAtomicLoad(LValue LV, SourceLocation SL,
+                                       AggValueSlot Slot) {
+  llvm::AtomicOrdering AO;
+  bool IsVolatile = LV.isVolatileQualified();
+  if (LV.getType()->isAtomicType()) {
+    AO = llvm::SequentiallyConsistent;
+  } else {
+    AO = llvm::Acquire;
+    IsVolatile = true;
+  }
+  return EmitAtomicLoad(LV, SL, AO, IsVolatile, Slot);
+}
+
 /// Emit a load from an l-value of atomic type.  Note that the r-value
 /// we produce is an r-value of the atomic *value* type.
 RValue CodeGenFunction::EmitAtomicLoad(LValue src, SourceLocation loc,
+                                       llvm::AtomicOrdering AO, bool IsVolatile,
                                        AggValueSlot resultSlot) {
   AtomicInfo atomics(*this, src);
   LValue LVal = atomics.getAtomicLValue();
@@ -1060,11 +1096,11 @@ RValue CodeGenFunction::EmitAtomicLoad(LValue src, SourceLocation loc,
   // Okay, we're doing this natively.
   llvm::Value *addr = atomics.emitCastToAtomicIntPointer(SrcAddr);
   llvm::LoadInst *load = Builder.CreateLoad(addr, "atomic-load");
-  load->setAtomic(llvm::SequentiallyConsistent);
+  load->setAtomic(AO);
 
   // Other decoration.
   load->setAlignment(src.getAlignment().getQuantity());
-  if (src.isVolatileQualified())
+  if (IsVolatile)
     load->setVolatile(true);
   if (src.getTBAAInfo())
     CGM.DecorateInstruction(load, src.getTBAAInfo());
@@ -1161,12 +1197,27 @@ llvm::Value *AtomicInfo::convertRValueToInt(RValue RVal) const {
                                        getAtomicAlignment().getQuantity());
 }
 
+void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue lvalue,
+                                      bool isInit) {
+  bool IsVolatile = lvalue.isVolatileQualified();
+  llvm::AtomicOrdering AO;
+  if (lvalue.getType()->isAtomicType()) {
+    AO = llvm::SequentiallyConsistent;
+  } else {
+    AO = llvm::Release;
+    IsVolatile = true;
+  }
+  return EmitAtomicStore(rvalue, lvalue, AO, IsVolatile, isInit);
+}
+
 /// Emit a store to an l-value of atomic type.
 ///
 /// Note that the r-value is expected to be an r-value *of the atomic
 /// type*; this means that for aggregate r-values, it should include
 /// storage for any padding that was necessary.
-void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, bool isInit) {
+void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest,
+                                      llvm::AtomicOrdering AO, bool IsVolatile,
+                                      bool isInit) {
   // If this is an aggregate r-value, it should agree in type except
   // maybe for address-space qualification.
   assert(!rvalue.isAggregate() ||
@@ -1209,11 +1260,11 @@ void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, bool isInit) {
   llvm::StoreInst *store = Builder.CreateStore(intValue, addr);
 
   // Initializations don't need to be atomic.
-  if (!isInit) store->setAtomic(llvm::SequentiallyConsistent);
+  if (!isInit) store->setAtomic(AO);
 
   // Other decoration.
   store->setAlignment(dest.getAlignment().getQuantity());
-  if (dest.isVolatileQualified())
+  if (IsVolatile)
     store->setVolatile(true);
   if (dest.getTBAAInfo())
     CGM.DecorateInstruction(store, dest.getTBAAInfo());