- Add MachineInstrBundle.h and MachineInstrBundle.cpp. This includes a function

to finalize MI bundles (i.e. add BUNDLE instruction and computing register def
  and use lists of the BUNDLE instruction) and a pass to unpack bundles.
- Teach more of MachineBasic and MachineInstr methods to be bundle aware.
- Switch Thumb2 IT block to MI bundles and delete the hazard recognizer hack to
  prevent IT blocks from being broken apart.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146542 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineInstrBundle.cpp

@@ -0,0 +1,180 @@
+//===-- lib/CodeGen/MachineInstrBundle.cpp --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineInstrBundle.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/SmallVector.h"
+using namespace llvm;
+
+namespace {
+  class UnpackMachineBundles : public MachineFunctionPass {
+  public:
+    static char ID; // Pass identification
+    UnpackMachineBundles() : MachineFunctionPass(ID) {
+      initializeUnpackMachineBundlesPass(*PassRegistry::getPassRegistry());
+    }
+
+    virtual bool runOnMachineFunction(MachineFunction &MF);
+  };
+} // end anonymous namespace
+
+char UnpackMachineBundles::ID = 0;
+INITIALIZE_PASS(UnpackMachineBundles, "unpack-mi-bundle",
+                "Unpack machine instruction bundles", false, false)
+
+FunctionPass *llvm::createUnpackMachineBundlesPass() {
+  return new UnpackMachineBundles();
+}
+
+bool UnpackMachineBundles::runOnMachineFunction(MachineFunction &MF) {
+  bool Changed = false;
+  for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
+    MachineBasicBlock *MBB = &*I;
+
+    for (MachineBasicBlock::instr_iterator MII = MBB->instr_begin(),
+           MIE = MBB->instr_end(); MII != MIE; ) {
+      MachineInstr *MI = &*MII;
+
+      // Remove BUNDLE instruction and the InsideBundle flags from bundled
+      // instructions.
+      if (MI->isBundle()) {
+        while (++MII != MIE && MII->isInsideBundle()) {
+          MII->setIsInsideBundle(false);
+          for (unsigned i = 0, e = MII->getNumOperands(); i != e; ++i) {
+            MachineOperand &MO = MII->getOperand(i);
+            if (MO.isReg() && MO.isInternalRead())
+              MO.setIsInternalRead(false);
+          }
+        }
+        MI->eraseFromParent();
+
+        Changed = true;
+        continue;
+      }
+
+      ++MII;
+    }
+  }
+
+  return Changed;
+}
+
+/// FinalizeBundle - Finalize a machine instruction bundle which includes
+/// a sequence of instructions starting from FirstMI to LastMI (inclusive).
+/// This routine adds a BUNDLE instruction to represent the bundle, it adds
+/// IsInternalRead markers to MachineOperands which are defined inside the
+/// bundle, and it copies externally visible defs and uses to the BUNDLE
+/// instruction.
+void llvm::FinalizeBundle(MachineBasicBlock &MBB,
+                          MachineBasicBlock::instr_iterator FirstMI,
+                          MachineBasicBlock::instr_iterator LastMI) {
+  const TargetMachine &TM = MBB.getParent()->getTarget();
+  const TargetInstrInfo *TII = TM.getInstrInfo();
+  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
+
+  MachineInstrBuilder MIB = BuildMI(MBB, FirstMI, FirstMI->getDebugLoc(),
+                                    TII->get(TargetOpcode::BUNDLE));
+
+  SmallVector<unsigned, 8> LocalDefs;
+  SmallSet<unsigned, 8> LocalDefSet;
+  SmallSet<unsigned, 8> DeadDefSet;
+  SmallSet<unsigned, 8> KilledDefSet;
+  SmallVector<unsigned, 8> ExternUses;
+  SmallSet<unsigned, 8> ExternUseSet;
+  SmallSet<unsigned, 8> KilledUseSet;
+  SmallSet<unsigned, 8> UndefUseSet;
+  SmallVector<MachineOperand*, 4> Defs;
+  do {
+    for (unsigned i = 0, e = FirstMI->getNumOperands(); i != e; ++i) {
+      MachineOperand &MO = FirstMI->getOperand(i);
+      if (!MO.isReg())
+        continue;
+      if (MO.isDef()) {
+        Defs.push_back(&MO);
+        continue;
+      }
+
+      unsigned Reg = MO.getReg();
+      if (!Reg)
+        continue;
+      assert(TargetRegisterInfo::isPhysicalRegister(Reg));
+      if (LocalDefSet.count(Reg)) {
+        MO.setIsInternalRead();
+        if (MO.isKill())
+          // Internal def is now killed.
+          KilledDefSet.insert(Reg);
+      } else {
+        if (ExternUseSet.insert(Reg)) {
+          ExternUses.push_back(Reg);
+          if (MO.isUndef())
+            UndefUseSet.insert(Reg);
+        }
+        if (MO.isKill())
+          // External def is now killed.
+          KilledUseSet.insert(Reg);
+      }
+    }
+
+    for (unsigned i = 0, e = Defs.size(); i != e; ++i) {
+      MachineOperand &MO = *Defs[i];
+      unsigned Reg = MO.getReg();
+      if (!Reg)
+        continue;
+
+      if (LocalDefSet.insert(Reg)) {
+        LocalDefs.push_back(Reg);
+        if (MO.isDead()) {
+          DeadDefSet.insert(Reg);
+        }
+      } else {
+        // Re-defined inside the bundle, it's no longer killed.
+        KilledDefSet.erase(Reg);
+        if (!MO.isDead())
+          // Previously defined but dead.
+          DeadDefSet.erase(Reg);
+      }
+
+      if (!MO.isDead()) {
+        for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
+             unsigned SubReg = *SubRegs; ++SubRegs) {
+          if (LocalDefSet.insert(SubReg))
+            LocalDefs.push_back(SubReg);
+        }
+      }
+    }
+
+    FirstMI->setIsInsideBundle();
+    Defs.clear();
+  } while (FirstMI++ != LastMI);
+
+  SmallSet<unsigned, 8> Added;
+  for (unsigned i = 0, e = LocalDefs.size(); i != e; ++i) {
+    unsigned Reg = LocalDefs[i];
+    if (Added.insert(Reg)) {
+      // If it's not live beyond end of the bundle, mark it dead.
+      bool isDead = DeadDefSet.count(Reg) || KilledDefSet.count(Reg);
+      MIB.addReg(Reg, getDefRegState(true) | getDeadRegState(isDead) |
+                 getImplRegState(true));
+    }
+  }
+
+  for (unsigned i = 0, e = ExternUses.size(); i != e; ++i) {
+    unsigned Reg = ExternUses[i];
+    bool isKill = KilledUseSet.count(Reg);
+    bool isUndef = UndefUseSet.count(Reg);
+    MIB.addReg(Reg, getKillRegState(isKill) | getUndefRegState(isUndef) |
+               getImplRegState(true));
+  }
+}