4 files changed, 29 insertions, 8 deletions
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index dca68da2f3..69a3ae84ec 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -707,8 +707,9 @@ void MachineVerifier::verifyInlineAsm(const MachineInstr *MI) {
     report("Asm string must be an external symbol", MI);
   if (!MI->getOperand(1).isImm())
     report("Asm flags must be an immediate", MI);
-  // Allowed flags are Extra_HasSideEffects = 1, and Extra_IsAlignStack = 2.
-  if (!isUInt<2>(MI->getOperand(1).getImm()))
+  // Allowed flags are Extra_HasSideEffects = 1, Extra_IsAlignStack = 2,
+  // Extra_AsmDialect = 4, Extra_MayLoad = 8, and Extra_MayStore = 16.
+  if (!isUInt<5>(MI->getOperand(1).getImm()))
     report("Unknown asm flags", &MI->getOperand(1), 1);
 
   assert(InlineAsm::MIOp_FirstOperand == 2 && "Asm format changed");
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index 8ea0f8a3ea..496473d3a4 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -420,11 +420,6 @@ void ScheduleDAGInstrs::addVRegUseDeps(SUnit *SU, unsigned OperIdx) {
 /// Return true if MI is an instruction we are unable to reason about
 /// (like a call or something with unmodeled side effects).
 static inline bool isGlobalMemoryObject(AliasAnalysis *AA, MachineInstr *MI) {
-  if (MI->isInlineAsm()) {
-    // Until we can tell if an inline assembly instruction accesses
-    // memory, we must assume all such instructions do so.
-    return true;
-  }
   if (MI->isCall() || MI->hasUnmodeledSideEffects() ||
       (MI->hasOrderedMemoryRef() &&
        (!MI->mayLoad() || !MI->isInvariantLoad(AA))))
diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index d1baa3f716..5fc71cc223 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/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/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 85103d5750..eacba90f0c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/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()));