2 files changed, 26 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index d1baa3f7167..5fc71cc2238 100644
--- a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -903,6 +903,13 @@ EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
                           getZExtValue();
     MI->addOperand(MachineOperand::CreateImm(ExtraInfo));
 
+    // Set the MayLoad and MayStore flags.
+    if (ExtraInfo & InlineAsm::Extra_MayLoad)
+      MI->setFlag(MachineInstr::MayLoad);
+
+    if (ExtraInfo & InlineAsm::Extra_MayStore)
+      MI->setFlag(MachineInstr::MayStore);
+
     // Remember to operand index of the group flags.
     SmallVector<unsigned, 8> GroupIdx;
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 85103d5750a..eacba90f0ce 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6128,7 +6128,8 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
   const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc");
   AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc));
 
-  // Remember the HasSideEffect, AlignStack and AsmDialect bits as operand 3.
+  // Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore
+  // bits as operand 3.
   unsigned ExtraInfo = 0;
   if (IA->hasSideEffects())
     ExtraInfo |= InlineAsm::Extra_HasSideEffects;
@@ -6136,6 +6137,23 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
     ExtraInfo |= InlineAsm::Extra_IsAlignStack;
   // Set the asm dialect.
   ExtraInfo |= IA->getDialect() * InlineAsm::Extra_AsmDialect;
+
+  // Determine if this InlineAsm MayLoad or MayStore based on the constraints.
+  for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
+    TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
+
+    // Compute the constraint code and ConstraintType to use.
+    TLI.ComputeConstraintToUse(OpInfo, SDValue());
+
+    if (OpInfo.ConstraintType == TargetLowering::C_Memory ||
+        OpInfo.ConstraintType == TargetLowering::C_Other) {
+      if (OpInfo.Type == InlineAsm::isInput)
+        ExtraInfo |= InlineAsm::Extra_MayLoad;
+      else if (OpInfo.Type == InlineAsm::isOutput)
+        ExtraInfo |= InlineAsm::Extra_MayStore;
+    }
+  }
+
   AsmNodeOperands.push_back(DAG.getTargetConstant(ExtraInfo,
                                                   TLI.getPointerTy()));