[CodeGen] Add getMachineMemOperand + MachineMemOperand::Flags allocator helper wrapper. NFCI.

Pre-commit for D62726 on behalf of @luke (Luke Lau)

llvm-svn: 363257

llvm/include/llvm/CodeGen/MachineFunction.h

@@ -740,6 +740,12 @@ public:
   MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
                                           const AAMDNodes &AAInfo);
 
+  /// Allocate a new MachineMemOperand by copying an existing one,
+  /// replacing the flags. MachineMemOperands are owned
+  /// by the MachineFunction and need not be explicitly deallocated.
+  MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
+                                          MachineMemOperand::Flags Flags);
+
   using OperandCapacity = ArrayRecycler<MachineOperand>::Capacity;
 
   /// Allocate an array of MachineOperands. This is only intended for use by

llvm/lib/CodeGen/MachineFunction.cpp

@@ -430,6 +430,15 @@ MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
                                MMO->getOrdering(), MMO->getFailureOrdering());
 }
 
+MachineMemOperand *
+MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
+                                      MachineMemOperand::Flags Flags) {
+  return new (Allocator) MachineMemOperand(
+      MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlignment(),
+      MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),
+      MMO->getOrdering(), MMO->getFailureOrdering());
+}
+
 MachineInstr::ExtraInfo *
 MachineFunction::createMIExtraInfo(ArrayRef<MachineMemOperand *> MMOs,
                                    MCSymbol *PreInstrSymbol,

llvm/lib/Target/X86/X86InstrInfo.cpp

@@ -5149,10 +5149,7 @@ extractLoadMMOs(ArrayRef<MachineMemOperand *> MMOs, MachineFunction &MF) {
     } else {
       // Clone the MMO and unset the store flag.
       LoadMMOs.push_back(MF.getMachineMemOperand(
-          MMO->getPointerInfo(), MMO->getFlags() & ~MachineMemOperand::MOStore,
-          MMO->getSize(), MMO->getBaseAlignment(), MMO->getAAInfo(), nullptr,
-          MMO->getSyncScopeID(), MMO->getOrdering(),
-          MMO->getFailureOrdering()));
+          MMO, MMO->getFlags() & ~MachineMemOperand::MOStore));
     }
   }
 
@@ -5173,10 +5170,7 @@ extractStoreMMOs(ArrayRef<MachineMemOperand *> MMOs, MachineFunction &MF) {
     } else {
       // Clone the MMO and unset the load flag.
       StoreMMOs.push_back(MF.getMachineMemOperand(
-          MMO->getPointerInfo(), MMO->getFlags() & ~MachineMemOperand::MOLoad,
-          MMO->getSize(), MMO->getBaseAlignment(), MMO->getAAInfo(), nullptr,
-          MMO->getSyncScopeID(), MMO->getOrdering(),
-          MMO->getFailureOrdering()));
+          MMO, MMO->getFlags() & ~MachineMemOperand::MOLoad));
     }
   }