1 files changed, 27 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/MachineInstrBundle.cpp b/llvm/lib/CodeGen/MachineInstrBundle.cpp
index da29ffc..a8dc614 100644
--- a/llvm/lib/CodeGen/MachineInstrBundle.cpp
+++ b/llvm/lib/CodeGen/MachineInstrBundle.cpp
@@ -136,6 +136,8 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
   SmallSetVector<Register, 8> ExternUses;
   SmallSet<Register, 8> KilledUseSet;
   SmallSet<Register, 8> UndefUseSet;
+  SmallVector<std::pair<Register, Register>> TiedOperands;
+  SmallVector<MachineInstr *> MemMIs;
   for (auto MII = FirstMI; MII != LastMI; ++MII) {
     // Debug instructions have no effects to track.
     if (MII->isDebugInstr())
@@ -161,6 +163,15 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
           // External def is now killed.
           KilledUseSet.insert(Reg);
         }
+        if (MO.isTied() && Reg.isVirtual()) {
+          // Record tied operand constraints that involve virtual registers so
+          // that bundles that are formed pre-register allocation reflect the
+          // relevant constraints.
+          unsigned TiedIdx = MII->findTiedOperandIdx(MO.getOperandNo());
+          MachineOperand &TiedMO = MII->getOperand(TiedIdx);
+          Register DefReg = TiedMO.getReg();
+          TiedOperands.emplace_back(DefReg, Reg);
+        }
       }
     }
 
@@ -190,6 +201,9 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
       MIB.setMIFlag(MachineInstr::FrameSetup);
     if (MII->getFlag(MachineInstr::FrameDestroy))
       MIB.setMIFlag(MachineInstr::FrameDestroy);
+
+    if (MII->mayLoadOrStore())
+      MemMIs.push_back(&*MII);
   }
 
   for (Register Reg : LocalDefs) {
@@ -203,8 +217,20 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
     bool isKill = KilledUseSet.contains(Reg);
     bool isUndef = UndefUseSet.contains(Reg);
     MIB.addReg(Reg, getKillRegState(isKill) | getUndefRegState(isUndef) |
-               getImplRegState(true));
+                        getImplRegState(true));
   }
+
+  for (auto [DefReg, UseReg] : TiedOperands) {
+    unsigned DefIdx =
+        std::distance(LocalDefs.begin(), llvm::find(LocalDefs, DefReg));
+    unsigned UseIdx =
+        std::distance(ExternUses.begin(), llvm::find(ExternUses, UseReg));
+    assert(DefIdx < LocalDefs.size());
+    assert(UseIdx < ExternUses.size());
+    MIB->tieOperands(DefIdx, LocalDefs.size() + UseIdx);
+  }
+
+  MIB->cloneMergedMemRefs(MF, MemMIs);
 }
 
 /// finalizeBundle - Same functionality as the previous finalizeBundle except