[CodeGen] Add "const" to MachineInstr::mayAlias

Summary:
The basic idea here is to make it possible to use
MachineInstr::mayAlias also when the MachineInstr
is const (or the "Other" MachineInstr is const).

The addition of const in MachineInstr::mayAlias
then rippled down to the need for adding const
in several other places, such as
TargetTransformInfo::getMemOperandWithOffset.

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, MatzeB, arsenm, jvesely, nhaehnle, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60856

llvm-svn: 358744

21 files changed, 98 insertions, 75 deletions

diff --git a/llvm/include/llvm/CodeGen/MachineInstr.h b/llvm/include/llvm/CodeGen/MachineInstr.h
index a85fee7bf4b..5f671de0d9b 100644
--- a/llvm/include/llvm/CodeGen/MachineInstr.h
+++ b/llvm/include/llvm/CodeGen/MachineInstr.h
@@ -1378,7 +1378,7 @@ public:
   /// @param AA Optional alias analysis, used to compare memory operands.
   /// @param Other MachineInstr to check aliasing against.
   /// @param UseTBAA Whether to pass TBAA information to alias analysis.
-  bool mayAlias(AliasAnalysis *AA, MachineInstr &Other, bool UseTBAA);
+  bool mayAlias(AliasAnalysis *AA, const MachineInstr &Other, bool UseTBAA) const;
 
   /// Return true if this instruction may have an ordered
   /// or volatile memory reference, or if the information describing the memory
diff --git a/llvm/include/llvm/CodeGen/TargetInstrInfo.h b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
index b732be625de..3ba4d406461 100644
--- a/llvm/include/llvm/CodeGen/TargetInstrInfo.h
+++ b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
@@ -1144,8 +1144,9 @@ public:
 
   /// Get the base operand and byte offset of an instruction that reads/writes
   /// memory.
-  virtual bool getMemOperandWithOffset(MachineInstr &MI,
-                                       MachineOperand *&BaseOp, int64_t &Offset,
+  virtual bool getMemOperandWithOffset(const MachineInstr &MI,
+                                       const MachineOperand *&BaseOp,
+                                       int64_t &Offset,
                                        const TargetRegisterInfo *TRI) const {
     return false;
   }
@@ -1170,8 +1171,8 @@ public:
   /// or
   ///   DAG->addMutation(createStoreClusterDAGMutation(DAG->TII, DAG->TRI));
   /// to TargetPassConfig::createMachineScheduler() to have an effect.
-  virtual bool shouldClusterMemOps(MachineOperand &BaseOp1,
-                                   MachineOperand &BaseOp2,
+  virtual bool shouldClusterMemOps(const MachineOperand &BaseOp1,
+                                   const MachineOperand &BaseOp2,
                                    unsigned NumLoads) const {
     llvm_unreachable("target did not implement shouldClusterMemOps()");
   }
@@ -1548,7 +1549,8 @@ public:
   /// See also MachineInstr::mayAlias, which is implemented on top of this
   /// function.
   virtual bool
-  areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+  areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                  const MachineInstr &MIb,
                                   AliasAnalysis *AA = nullptr) const {
     assert((MIa.mayLoad() || MIa.mayStore()) &&
            "MIa must load from or modify a memory location");
diff --git a/llvm/lib/CodeGen/ImplicitNullChecks.cpp b/llvm/lib/CodeGen/ImplicitNullChecks.cpp
index 68110314151..dff6d02b06e 100644
--- a/llvm/lib/CodeGen/ImplicitNullChecks.cpp
+++ b/llvm/lib/CodeGen/ImplicitNullChecks.cpp
@@ -180,7 +180,8 @@ class ImplicitNullChecks : public MachineFunctionPass {
   /// Returns AR_NoAlias if \p MI memory operation does not alias with
   /// \p PrevMI, AR_MayAlias if they may alias and AR_WillAliasEverything if
   /// they may alias and any further memory operation may alias with \p PrevMI.
-  AliasResult areMemoryOpsAliased(MachineInstr &MI, MachineInstr *PrevMI);
+  AliasResult areMemoryOpsAliased(const MachineInstr &MI,
+                                  const MachineInstr *PrevMI) const;
 
   enum SuitabilityResult {
     SR_Suitable,
@@ -194,7 +195,8 @@ class ImplicitNullChecks : public MachineFunctionPass {
   /// no sense to continue lookup due to any other instruction will not be able
   /// to be used. \p PrevInsts is the set of instruction seen since
   /// the explicit null check on \p PointerReg.
-  SuitabilityResult isSuitableMemoryOp(MachineInstr &MI, unsigned PointerReg,
+  SuitabilityResult isSuitableMemoryOp(const MachineInstr &MI,
+                                       unsigned PointerReg,
                                        ArrayRef<MachineInstr *> PrevInsts);
 
   /// Return true if \p FaultingMI can be hoisted from after the
@@ -318,8 +320,8 @@ static bool AnyAliasLiveIn(const TargetRegisterInfo *TRI,
 }
 
 ImplicitNullChecks::AliasResult
-ImplicitNullChecks::areMemoryOpsAliased(MachineInstr &MI,
-                                        MachineInstr *PrevMI) {
+ImplicitNullChecks::areMemoryOpsAliased(const MachineInstr &MI,
+                                        const MachineInstr *PrevMI) const {
   // If it is not memory access, skip the check.
   if (!(PrevMI->mayStore() || PrevMI->mayLoad()))
     return AR_NoAlias;
@@ -356,10 +358,11 @@ ImplicitNullChecks::areMemoryOpsAliased(MachineInstr &MI,
 }
 
 ImplicitNullChecks::SuitabilityResult
-ImplicitNullChecks::isSuitableMemoryOp(MachineInstr &MI, unsigned PointerReg,
+ImplicitNullChecks::isSuitableMemoryOp(const MachineInstr &MI,
+                                       unsigned PointerReg,
                                        ArrayRef<MachineInstr *> PrevInsts) {
   int64_t Offset;
-  MachineOperand *BaseOp;
+  const MachineOperand *BaseOp;
 
   if (!TII->getMemOperandWithOffset(MI, BaseOp, Offset, TRI) ||
       !BaseOp->isReg() || BaseOp->getReg() != PointerReg)
diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 26d58340b61..7fdcb31aea7 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1181,8 +1181,8 @@ bool MachineInstr::isSafeToMove(AliasAnalysis *AA, bool &SawStore) const {
   return true;
 }
 
-bool MachineInstr::mayAlias(AliasAnalysis *AA, MachineInstr &Other,
-                            bool UseTBAA) {
+bool MachineInstr::mayAlias(AliasAnalysis *AA, const MachineInstr &Other,
+                            bool UseTBAA) const {
   const MachineFunction *MF = getMF();
   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
   const MachineFrameInfo &MFI = MF->getFrameInfo();
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index 1f7c48fe215..fde6531e160 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -597,7 +597,7 @@ void SwingSchedulerDAG::addLoopCarriedDependences(AliasAnalysis *AA) {
           // First, perform the cheaper check that compares the base register.
           // If they are the same and the load offset is less than the store
           // offset, then mark the dependence as loop carried potentially.
-          MachineOperand *BaseOp1, *BaseOp2;
+          const MachineOperand *BaseOp1, *BaseOp2;
           int64_t Offset1, Offset2;
           if (TII->getMemOperandWithOffset(LdMI, BaseOp1, Offset1, TRI) &&
               TII->getMemOperandWithOffset(MI, BaseOp2, Offset2, TRI)) {
@@ -2725,7 +2725,7 @@ void SwingSchedulerDAG::addBranches(MBBVectorTy &PrologBBs,
 /// during each iteration. Set Delta to the amount of the change.
 bool SwingSchedulerDAG::computeDelta(MachineInstr &MI, unsigned &Delta) {
   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
-  MachineOperand *BaseOp;
+  const MachineOperand *BaseOp;
   int64_t Offset;
   if (!TII->getMemOperandWithOffset(MI, BaseOp, Offset, TRI))
     return false;
@@ -3139,7 +3139,7 @@ bool SwingSchedulerDAG::isLoopCarriedDep(SUnit *Source, const SDep &Dep,
   if (!computeDelta(*SI, DeltaS) || !computeDelta(*DI, DeltaD))
     return true;
 
-  MachineOperand *BaseOpS, *BaseOpD;
+  const MachineOperand *BaseOpS, *BaseOpD;
   int64_t OffsetS, OffsetD;
   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
   if (!TII->getMemOperandWithOffset(*SI, BaseOpS, OffsetS, TRI) ||
diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index d56ea43437b..4b61dad4ac5 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -1466,10 +1466,10 @@ namespace {
 class BaseMemOpClusterMutation : public ScheduleDAGMutation {
   struct MemOpInfo {
     SUnit *SU;
-    MachineOperand *BaseOp;
+    const MachineOperand *BaseOp;
     int64_t Offset;
 
-    MemOpInfo(SUnit *su, MachineOperand *Op, int64_t ofs)
+    MemOpInfo(SUnit *su, const MachineOperand *Op, int64_t ofs)
         : SU(su), BaseOp(Op), Offset(ofs) {}
 
     bool operator<(const MemOpInfo &RHS) const {
@@ -1555,7 +1555,7 @@ void BaseMemOpClusterMutation::clusterNeighboringMemOps(
     ArrayRef<SUnit *> MemOps, ScheduleDAGInstrs *DAG) {
   SmallVector<MemOpInfo, 32> MemOpRecords;
   for (SUnit *SU : MemOps) {
-    MachineOperand *BaseOp;
+    const MachineOperand *BaseOp;
     int64_t Offset;
     if (TII->getMemOperandWithOffset(*SU->getInstr(), BaseOp, Offset, TRI))
       MemOpRecords.push_back(MemOpInfo(SU, BaseOp, Offset));
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index f4fcbeb387f..fc61a34354c 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -715,7 +715,7 @@ static bool SinkingPreventsImplicitNullCheck(MachineInstr &MI,
       !PredBB->getTerminator()->getMetadata(LLVMContext::MD_make_implicit))
     return false;
 
-  MachineOperand *BaseOp;
+  const MachineOperand *BaseOp;
   int64_t Offset;
   if (!TII->getMemOperandWithOffset(MI, BaseOp, Offset, TRI))
     return false;
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 12f2576f51e..2819c50c8aa 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -927,9 +927,9 @@ bool AArch64InstrInfo::isCoalescableExtInstr(const MachineInstr &MI,
 }
 
 bool AArch64InstrInfo::areMemAccessesTriviallyDisjoint(
-    MachineInstr &MIa, MachineInstr &MIb, AliasAnalysis *AA) const {
+    const MachineInstr &MIa, const MachineInstr &MIb, AliasAnalysis *AA) const {
   const TargetRegisterInfo *TRI = &getRegisterInfo();
-  MachineOperand *BaseOpA = nullptr, *BaseOpB = nullptr;
+  const MachineOperand *BaseOpA = nullptr, *BaseOpB = nullptr;
   int64_t OffsetA = 0, OffsetB = 0;
   unsigned WidthA = 0, WidthB = 0;
 
@@ -1894,7 +1894,7 @@ unsigned AArch64InstrInfo::convertToFlagSettingOpc(unsigned Opc,
 
 // Is this a candidate for ld/st merging or pairing?  For example, we don't
 // touch volatiles or load/stores that have a hint to avoid pair formation.
-bool AArch64InstrInfo::isCandidateToMergeOrPair(MachineInstr &MI) const {
+bool AArch64InstrInfo::isCandidateToMergeOrPair(const MachineInstr &MI) const {
   // If this is a volatile load/store, don't mess with it.
   if (MI.hasOrderedMemoryRef())
     return false;
@@ -1936,8 +1936,8 @@ bool AArch64InstrInfo::isCandidateToMergeOrPair(MachineInstr &MI) const {
   return true;
 }
 
-bool AArch64InstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
-                                          MachineOperand *&BaseOp,
+bool AArch64InstrInfo::getMemOperandWithOffset(const MachineInstr &LdSt,
+                                          const MachineOperand *&BaseOp,
                                           int64_t &Offset,
                                           const TargetRegisterInfo *TRI) const {
   unsigned Width;
@@ -1945,7 +1945,7 @@ bool AArch64InstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
 }
 
 bool AArch64InstrInfo::getMemOperandWithOffsetWidth(
-    MachineInstr &LdSt, MachineOperand *&BaseOp, int64_t &Offset,
+    const MachineInstr &LdSt, const MachineOperand *&BaseOp, int64_t &Offset,
     unsigned &Width, const TargetRegisterInfo *TRI) const {
   assert(LdSt.mayLoadOrStore() && "Expected a memory operation.");
   // Handle only loads/stores with base register followed by immediate offset.
@@ -2244,11 +2244,11 @@ static bool shouldClusterFI(const MachineFrameInfo &MFI, int FI1,
 /// Detect opportunities for ldp/stp formation.
 ///
 /// Only called for LdSt for which getMemOperandWithOffset returns true.
-bool AArch64InstrInfo::shouldClusterMemOps(MachineOperand &BaseOp1,
-                                           MachineOperand &BaseOp2,
+bool AArch64InstrInfo::shouldClusterMemOps(const MachineOperand &BaseOp1,
+                                           const MachineOperand &BaseOp2,
                                            unsigned NumLoads) const {
-  MachineInstr &FirstLdSt = *BaseOp1.getParent();
-  MachineInstr &SecondLdSt = *BaseOp2.getParent();
+  const MachineInstr &FirstLdSt = *BaseOp1.getParent();
+  const MachineInstr &SecondLdSt = *BaseOp2.getParent();
   if (BaseOp1.getType() != BaseOp2.getType())
     return false;
 
@@ -4918,8 +4918,8 @@ AArch64InstrInfo::getOutliningCandidateInfo(
     // At this point, we have a stack instruction that we might need to
     // fix up. We'll handle it if it's a load or store.
     if (MI.mayLoadOrStore()) {
-      MachineOperand *Base; // Filled with the base operand of MI.
-      int64_t Offset;       // Filled with the offset of MI.
+      const MachineOperand *Base; // Filled with the base operand of MI.
+      int64_t Offset;             // Filled with the offset of MI.
 
       // Does it allow us to offset the base operand and is the base the
       // register SP?
@@ -5288,7 +5288,7 @@ AArch64InstrInfo::getOutliningType(MachineBasicBlock::iterator &MIT,
 
 void AArch64InstrInfo::fixupPostOutline(MachineBasicBlock &MBB) const {
   for (MachineInstr &MI : MBB) {
-    MachineOperand *Base;
+    const MachineOperand *Base;
     unsigned Width;
     int64_t Offset;
 
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.h b/llvm/lib/Target/AArch64/AArch64InstrInfo.h
index 148b7afabe6..b33edc5168b 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.h
@@ -54,7 +54,8 @@ public:
                              unsigned &DstReg, unsigned &SubIdx) const override;
 
   bool
-  areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+  areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                  const MachineInstr &MIb,
                                   AliasAnalysis *AA = nullptr) const override;
 
   unsigned isLoadFromStackSlot(const MachineInstr &MI,
@@ -100,16 +101,18 @@ public:
   static unsigned convertToFlagSettingOpc(unsigned Opc, bool &Is64Bit);
 
   /// Return true if this is a load/store that can be potentially paired/merged.
-  bool isCandidateToMergeOrPair(MachineInstr &MI) const;
+  bool isCandidateToMergeOrPair(const MachineInstr &MI) const;
 
   /// Hint that pairing the given load or store is unprofitable.
   static void suppressLdStPair(MachineInstr &MI);
 
-  bool getMemOperandWithOffset(MachineInstr &MI, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffset(const MachineInstr &MI,
+                               const MachineOperand *&BaseOp,
                                int64_t &Offset,
                                const TargetRegisterInfo *TRI) const override;
 
-  bool getMemOperandWithOffsetWidth(MachineInstr &MI, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffsetWidth(const MachineInstr &MI,
+                                    const MachineOperand *&BaseOp,
                                     int64_t &Offset, unsigned &Width,
                                     const TargetRegisterInfo *TRI) const;
 
@@ -123,7 +126,8 @@ public:
   static bool getMemOpInfo(unsigned Opcode, unsigned &Scale, unsigned &Width,
                            int64_t &MinOffset, int64_t &MaxOffset);
 
-  bool shouldClusterMemOps(MachineOperand &BaseOp1, MachineOperand &BaseOp2,
+  bool shouldClusterMemOps(const MachineOperand &BaseOp1,
+                           const MachineOperand &BaseOp2,
                            unsigned NumLoads) const override;
 
   void copyPhysRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
diff --git a/llvm/lib/Target/AArch64/AArch64StorePairSuppress.cpp b/llvm/lib/Target/AArch64/AArch64StorePairSuppress.cpp
index 27ddd7af271..0e84a00df00 100644
--- a/llvm/lib/Target/AArch64/AArch64StorePairSuppress.cpp
+++ b/llvm/lib/Target/AArch64/AArch64StorePairSuppress.cpp
@@ -147,7 +147,7 @@ bool AArch64StorePairSuppress::runOnMachineFunction(MachineFunction &MF) {
     for (auto &MI : MBB) {
       if (!isNarrowFPStore(MI))
         continue;
-      MachineOperand *BaseOp;
+      const MachineOperand *BaseOp;
       int64_t Offset;
       if (TII->getMemOperandWithOffset(MI, BaseOp, Offset, TRI) &&
           BaseOp->isReg()) {
diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
index 45b0a5b2a8d..8ce3fd2fd58 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -256,8 +256,8 @@ static bool isStride64(unsigned Opc) {
   }
 }
 
-bool SIInstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
-                                          MachineOperand *&BaseOp,
+bool SIInstrInfo::getMemOperandWithOffset(const MachineInstr &LdSt,
+                                          const MachineOperand *&BaseOp,
                                           int64_t &Offset,
                                           const TargetRegisterInfo *TRI) const {
   unsigned Opc = LdSt.getOpcode();
@@ -321,7 +321,7 @@ bool SIInstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
     if (SOffset && SOffset->isReg())
       return false;
 
-    MachineOperand *AddrReg = getNamedOperand(LdSt, AMDGPU::OpName::vaddr);
+    const MachineOperand *AddrReg = getNamedOperand(LdSt, AMDGPU::OpName::vaddr);
     if (!AddrReg)
       return false;
 
@@ -344,7 +344,7 @@ bool SIInstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
     if (!OffsetImm)
       return false;
 
-    MachineOperand *SBaseReg = getNamedOperand(LdSt, AMDGPU::OpName::sbase);
+    const MachineOperand *SBaseReg = getNamedOperand(LdSt, AMDGPU::OpName::sbase);
     BaseOp = SBaseReg;
     Offset = OffsetImm->getImm();
     assert(BaseOp->isReg() && "getMemOperandWithOffset only supports base "
@@ -353,7 +353,7 @@ bool SIInstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
   }
 
   if (isFLAT(LdSt)) {
-    MachineOperand *VAddr = getNamedOperand(LdSt, AMDGPU::OpName::vaddr);
+    const MachineOperand *VAddr = getNamedOperand(LdSt, AMDGPU::OpName::vaddr);
     if (VAddr) {
       // Can't analyze 2 offsets.
       if (getNamedOperand(LdSt, AMDGPU::OpName::saddr))
@@ -409,11 +409,11 @@ static bool memOpsHaveSameBasePtr(const MachineInstr &MI1,
   return Base1 == Base2;
 }
 
-bool SIInstrInfo::shouldClusterMemOps(MachineOperand &BaseOp1,
-                                      MachineOperand &BaseOp2,
+bool SIInstrInfo::shouldClusterMemOps(const MachineOperand &BaseOp1,
+                                      const MachineOperand &BaseOp2,
                                       unsigned NumLoads) const {
-  MachineInstr &FirstLdSt = *BaseOp1.getParent();
-  MachineInstr &SecondLdSt = *BaseOp2.getParent();
+  const MachineInstr &FirstLdSt = *BaseOp1.getParent();
+  const MachineInstr &SecondLdSt = *BaseOp2.getParent();
 
   if (!memOpsHaveSameBasePtr(FirstLdSt, BaseOp1, SecondLdSt, BaseOp2))
     return false;
@@ -2223,9 +2223,9 @@ static bool offsetsDoNotOverlap(int WidthA, int OffsetA,
   return LowOffset + LowWidth <= HighOffset;
 }
 
-bool SIInstrInfo::checkInstOffsetsDoNotOverlap(MachineInstr &MIa,
-                                               MachineInstr &MIb) const {
-  MachineOperand *BaseOp0, *BaseOp1;
+bool SIInstrInfo::checkInstOffsetsDoNotOverlap(const MachineInstr &MIa,
+                                               const MachineInstr &MIb) const {
+  const MachineOperand *BaseOp0, *BaseOp1;
   int64_t Offset0, Offset1;
 
   if (getMemOperandWithOffset(MIa, BaseOp0, Offset0, &RI) &&
@@ -2247,8 +2247,8 @@ bool SIInstrInfo::checkInstOffsetsDoNotOverlap(MachineInstr &MIa,
   return false;
 }
 
-bool SIInstrInfo::areMemAccessesTriviallyDisjoint(MachineInstr &MIa,
-                                                  MachineInstr &MIb,
+bool SIInstrInfo::areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                                  const MachineInstr &MIb,
                                                   AliasAnalysis *AA) const {
   assert((MIa.mayLoad() || MIa.mayStore()) &&
          "MIa must load from or modify a memory location");
diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.h b/llvm/lib/Target/AMDGPU/SIInstrInfo.h
index 13e3dbd3cfe..a22f5a68ee6 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.h
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.h
@@ -127,7 +127,8 @@ private:
   const TargetRegisterClass *
   getDestEquivalentVGPRClass(const MachineInstr &Inst) const;
 
-  bool checkInstOffsetsDoNotOverlap(MachineInstr &MIa, MachineInstr &MIb) const;
+  bool checkInstOffsetsDoNotOverlap(const MachineInstr &MIa,
+                                    const MachineInstr &MIb) const;
 
   unsigned findUsedSGPR(const MachineInstr &MI, int OpIndices[3]) const;
 
@@ -172,11 +173,13 @@ public:
                                int64_t &Offset1,
                                int64_t &Offset2) const override;
 
-  bool getMemOperandWithOffset(MachineInstr &LdSt, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffset(const MachineInstr &LdSt,
+                               const MachineOperand *&BaseOp,
                                int64_t &Offset,
                                const TargetRegisterInfo *TRI) const final;
 
-  bool shouldClusterMemOps(MachineOperand &BaseOp1, MachineOperand &BaseOp2,
+  bool shouldClusterMemOps(const MachineOperand &BaseOp1,
+                           const MachineOperand &BaseOp2,
                            unsigned NumLoads) const override;
 
   bool shouldScheduleLoadsNear(SDNode *Load0, SDNode *Load1, int64_t Offset0,
@@ -293,7 +296,8 @@ public:
              unsigned Kind) const override;
 
   bool
-  areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+  areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                  const MachineInstr &MIb,
                                   AliasAnalysis *AA = nullptr) const override;
 
   bool isFoldableCopy(const MachineInstr &MI) const;
diff --git a/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp b/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
index 343c8b6e7a6..ebbdf80f956 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
+++ b/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
@@ -1956,7 +1956,7 @@ void SIScheduleDAGMI::schedule()
 
   for (unsigned i = 0, e = (unsigned)SUnits.size(); i != e; ++i) {
     SUnit *SU = &SUnits[i];
-    MachineOperand *BaseLatOp;
+    const MachineOperand *BaseLatOp;
     int64_t OffLatReg;
     if (SITII->isLowLatencyInstruction(*SU->getInstr())) {
       IsLowLatencySU[i] = 1;
diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
index 3ecb1428213..545dd15dde2 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -1854,7 +1854,8 @@ DFAPacketizer *HexagonInstrInfo::CreateTargetScheduleState(
 //  S2_storeri_io %r29, 132, killed %r1; flags:  mem:ST4[FixedStack1]
 // Currently AA considers the addresses in these instructions to be aliasing.
 bool HexagonInstrInfo::areMemAccessesTriviallyDisjoint(
-    MachineInstr &MIa, MachineInstr &MIb, AliasAnalysis *AA) const {
+    const MachineInstr &MIa, const MachineInstr &MIb,
+    AliasAnalysis *AA) const {
   if (MIa.hasUnmodeledSideEffects() || MIb.hasUnmodeledSideEffects() ||
       MIa.hasOrderedMemoryRef() || MIb.hasOrderedMemoryRef())
     return false;
@@ -2925,7 +2926,7 @@ bool HexagonInstrInfo::addLatencyToSchedule(const MachineInstr &MI1,
 
 /// Get the base register and byte offset of a load/store instr.
 bool HexagonInstrInfo::getMemOperandWithOffset(
-    MachineInstr &LdSt, MachineOperand *&BaseOp, int64_t &Offset,
+    const MachineInstr &LdSt, const MachineOperand *&BaseOp, int64_t &Offset,
     const TargetRegisterInfo *TRI) const {
   unsigned AccessSize = 0;
   BaseOp = getBaseAndOffset(LdSt, Offset, AccessSize);
diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.h b/llvm/lib/Target/Hexagon/HexagonInstrInfo.h
index 688af2a9089..8d339641ba4 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.h
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.h
@@ -215,7 +215,8 @@ public:
   bool expandPostRAPseudo(MachineInstr &MI) const override;
 
   /// Get the base register and byte offset of a load/store instr.
-  bool getMemOperandWithOffset(MachineInstr &LdSt, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffset(const MachineInstr &LdSt,
+                               const MachineOperand *&BaseOp,
                                int64_t &Offset,
                                const TargetRegisterInfo *TRI) const override;
 
@@ -295,7 +296,8 @@ public:
   // memory addresses. This function returns true if two MIs access different
   // memory addresses and false otherwise.
   bool
-  areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+  areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                  const MachineInstr &MIb,
                                   AliasAnalysis *AA = nullptr) const override;
 
   /// For instructions with a base and offset, return the position of the
diff --git a/llvm/lib/Target/Lanai/LanaiInstrInfo.cpp b/llvm/lib/Target/Lanai/LanaiInstrInfo.cpp
index 93db67c4e3e..dd45797edae 100644
--- a/llvm/lib/Target/Lanai/LanaiInstrInfo.cpp
+++ b/llvm/lib/Target/Lanai/LanaiInstrInfo.cpp
@@ -86,7 +86,8 @@ void LanaiInstrInfo::loadRegFromStackSlot(
 }
 
 bool LanaiInstrInfo::areMemAccessesTriviallyDisjoint(
-    MachineInstr &MIa, MachineInstr &MIb, AliasAnalysis * /*AA*/) const {
+    const MachineInstr &MIa, const MachineInstr &MIb,
+    AliasAnalysis * /*AA*/) const {
   assert(MIa.mayLoadOrStore() && "MIa must be a load or store.");
   assert(MIb.mayLoadOrStore() && "MIb must be a load or store.");
 
@@ -100,7 +101,7 @@ bool LanaiInstrInfo::areMemAccessesTriviallyDisjoint(
   // the width doesn't overlap the offset of a higher memory access,
   // then the memory accesses are different.
   const TargetRegisterInfo *TRI = &getRegisterInfo();
-  MachineOperand *BaseOpA = nullptr, *BaseOpB = nullptr;
+  const MachineOperand *BaseOpA = nullptr, *BaseOpB = nullptr;
   int64_t OffsetA = 0, OffsetB = 0;
   unsigned int WidthA = 0, WidthB = 0;
   if (getMemOperandWithOffsetWidth(MIa, BaseOpA, OffsetA, WidthA, TRI) &&
@@ -755,7 +756,7 @@ unsigned LanaiInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
 }
 
 bool LanaiInstrInfo::getMemOperandWithOffsetWidth(
-    MachineInstr &LdSt, MachineOperand *&BaseOp, int64_t &Offset,
+    const MachineInstr &LdSt, const MachineOperand *&BaseOp, int64_t &Offset,
     unsigned &Width, const TargetRegisterInfo * /*TRI*/) const {
   // Handle only loads/stores with base register followed by immediate offset
   // and with add as ALU op.
@@ -793,8 +794,8 @@ bool LanaiInstrInfo::getMemOperandWithOffsetWidth(
   return true;
 }
 
-bool LanaiInstrInfo::getMemOperandWithOffset(MachineInstr &LdSt,
-                                        MachineOperand *&BaseOp,
+bool LanaiInstrInfo::getMemOperandWithOffset(const MachineInstr &LdSt,
+                                        const MachineOperand *&BaseOp,
                                         int64_t &Offset,
                                         const TargetRegisterInfo *TRI) const {
   switch (LdSt.getOpcode()) {
diff --git a/llvm/lib/Target/Lanai/LanaiInstrInfo.h b/llvm/lib/Target/Lanai/LanaiInstrInfo.h
index feda529610c..d71424aeb0b 100644
--- a/llvm/lib/Target/Lanai/LanaiInstrInfo.h
+++ b/llvm/lib/Target/Lanai/LanaiInstrInfo.h
@@ -35,7 +35,8 @@ public:
     return RegisterInfo;
   }
 
-  bool areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+  bool areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                       const MachineInstr &MIb,
                                        AliasAnalysis *AA) const override;
 
   unsigned isLoadFromStackSlot(const MachineInstr &MI,
@@ -67,11 +68,13 @@ public:
 
   bool expandPostRAPseudo(MachineInstr &MI) const override;
 
-  bool getMemOperandWithOffset(MachineInstr &LdSt, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffset(const MachineInstr &LdSt,
+                               const MachineOperand *&BaseOp,
                                int64_t &Offset,
                                const TargetRegisterInfo *TRI) const override;
 
-  bool getMemOperandWithOffsetWidth(MachineInstr &LdSt, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffsetWidth(const MachineInstr &LdSt,
+                                    const MachineOperand *&BaseOp,
                                     int64_t &Offset, unsigned &Width,
                                     const TargetRegisterInfo *TRI) const;
 
diff --git a/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp b/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
index cb963a10010..54977d93919 100644
--- a/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
@@ -1782,7 +1782,8 @@ void SystemZInstrInfo::loadImmediate(MachineBasicBlock &MBB,
 }
 
 bool SystemZInstrInfo::
-areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                const MachineInstr &MIb,
                                 AliasAnalysis *AA) const {
 
   if (!MIa.hasOneMemOperand() || !MIb.hasOneMemOperand())
diff --git a/llvm/lib/Target/SystemZ/SystemZInstrInfo.h b/llvm/lib/Target/SystemZ/SystemZInstrInfo.h
index c5d1917b329..150028b1e55 100644
--- a/llvm/lib/Target/SystemZ/SystemZInstrInfo.h
+++ b/llvm/lib/Target/SystemZ/SystemZInstrInfo.h
@@ -313,7 +313,8 @@ public:
   // addresses. This function returns true if two MIs access different
   // memory addresses and false otherwise.
   bool
-  areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
+  areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
+                                  const MachineInstr &MIb,
                                   AliasAnalysis *AA = nullptr) const override;
 };
 
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 7b68cc2dc3a..480292b06a3 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -2958,7 +2958,7 @@ static unsigned getLoadStoreRegOpcode(unsigned Reg,
 }
 
 bool X86InstrInfo::getMemOperandWithOffset(
-    MachineInstr &MemOp, MachineOperand *&BaseOp, int64_t &Offset,
+    const MachineInstr &MemOp, const MachineOperand *&BaseOp, int64_t &Offset,
     const TargetRegisterInfo *TRI) const {
   const MCInstrDesc &Desc = MemOp.getDesc();
   int MemRefBegin = X86II::getMemoryOperandNo(Desc.TSFlags);
diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h
index 49f76606e8d..de4ed6998f5 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -288,7 +288,8 @@ public:
                      SmallVectorImpl<MachineOperand> &Cond,
                      bool AllowModify) const override;
 
-  bool getMemOperandWithOffset(MachineInstr &LdSt, MachineOperand *&BaseOp,
+  bool getMemOperandWithOffset(const MachineInstr &LdSt,
+                               const MachineOperand *&BaseOp,
                                int64_t &Offset,
                                const TargetRegisterInfo *TRI) const override;
   bool analyzeBranchPredicate(MachineBasicBlock &MBB,