1 //===-- lib/CodeGen/MachineInstrBundle.cpp --------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/CodeGen/MachineInstrBundle.h"
11 #include "llvm/CodeGen/MachineInstrBuilder.h"
12 #include "llvm/CodeGen/Passes.h"
13 #include "llvm/CodeGen/MachineFunctionPass.h"
14 #include "llvm/Target/TargetInstrInfo.h"
15 #include "llvm/Target/TargetMachine.h"
16 #include "llvm/Target/TargetRegisterInfo.h"
17 #include "llvm/ADT/SmallSet.h"
18 #include "llvm/ADT/SmallVector.h"
22 class UnpackMachineBundles : public MachineFunctionPass {
24 static char ID; // Pass identification
25 UnpackMachineBundles() : MachineFunctionPass(ID) {
26 initializeUnpackMachineBundlesPass(*PassRegistry::getPassRegistry());
29 virtual bool runOnMachineFunction(MachineFunction &MF);
31 } // end anonymous namespace
33 char UnpackMachineBundles::ID = 0;
34 INITIALIZE_PASS(UnpackMachineBundles, "unpack-mi-bundle",
35 "Unpack machine instruction bundles", false, false)
37 FunctionPass *llvm::createUnpackMachineBundlesPass() {
38 return new UnpackMachineBundles();
41 bool UnpackMachineBundles::runOnMachineFunction(MachineFunction &MF) {
43 for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
44 MachineBasicBlock *MBB = &*I;
46 for (MachineBasicBlock::instr_iterator MII = MBB->instr_begin(),
47 MIE = MBB->instr_end(); MII != MIE; ) {
48 MachineInstr *MI = &*MII;
50 // Remove BUNDLE instruction and the InsideBundle flags from bundled
53 while (++MII != MIE && MII->isInsideBundle()) {
54 MII->setIsInsideBundle(false);
55 for (unsigned i = 0, e = MII->getNumOperands(); i != e; ++i) {
56 MachineOperand &MO = MII->getOperand(i);
57 if (MO.isReg() && MO.isInternalRead())
58 MO.setIsInternalRead(false);
61 MI->eraseFromParent();
74 /// finalizeBundle - Finalize a machine instruction bundle which includes
75 /// a sequence of instructions starting from FirstMI to LastMI (exclusive).
76 /// This routine adds a BUNDLE instruction to represent the bundle, it adds
77 /// IsInternalRead markers to MachineOperands which are defined inside the
78 /// bundle, and it copies externally visible defs and uses to the BUNDLE
80 void llvm::finalizeBundle(MachineBasicBlock &MBB,
81 MachineBasicBlock::instr_iterator FirstMI,
82 MachineBasicBlock::instr_iterator LastMI) {
83 assert(FirstMI != LastMI && "Empty bundle?");
85 const TargetMachine &TM = MBB.getParent()->getTarget();
86 const TargetInstrInfo *TII = TM.getInstrInfo();
87 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
89 MachineInstrBuilder MIB = BuildMI(MBB, FirstMI, FirstMI->getDebugLoc(),
90 TII->get(TargetOpcode::BUNDLE));
92 SmallVector<unsigned, 8> LocalDefs;
93 SmallSet<unsigned, 8> LocalDefSet;
94 SmallSet<unsigned, 8> DeadDefSet;
95 SmallSet<unsigned, 8> KilledDefSet;
96 SmallVector<unsigned, 8> ExternUses;
97 SmallSet<unsigned, 8> ExternUseSet;
98 SmallSet<unsigned, 8> KilledUseSet;
99 SmallSet<unsigned, 8> UndefUseSet;
100 SmallVector<MachineOperand*, 4> Defs;
101 for (; FirstMI != LastMI; ++FirstMI) {
102 for (unsigned i = 0, e = FirstMI->getNumOperands(); i != e; ++i) {
103 MachineOperand &MO = FirstMI->getOperand(i);
111 unsigned Reg = MO.getReg();
114 assert(TargetRegisterInfo::isPhysicalRegister(Reg));
115 if (LocalDefSet.count(Reg)) {
116 MO.setIsInternalRead();
118 // Internal def is now killed.
119 KilledDefSet.insert(Reg);
121 if (ExternUseSet.insert(Reg)) {
122 ExternUses.push_back(Reg);
124 UndefUseSet.insert(Reg);
127 // External def is now killed.
128 KilledUseSet.insert(Reg);
132 for (unsigned i = 0, e = Defs.size(); i != e; ++i) {
133 MachineOperand &MO = *Defs[i];
134 unsigned Reg = MO.getReg();
138 if (LocalDefSet.insert(Reg)) {
139 LocalDefs.push_back(Reg);
141 DeadDefSet.insert(Reg);
144 // Re-defined inside the bundle, it's no longer killed.
145 KilledDefSet.erase(Reg);
147 // Previously defined but dead.
148 DeadDefSet.erase(Reg);
152 for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
153 unsigned SubReg = *SubRegs; ++SubRegs) {
154 if (LocalDefSet.insert(SubReg))
155 LocalDefs.push_back(SubReg);
160 FirstMI->setIsInsideBundle();
164 SmallSet<unsigned, 8> Added;
165 for (unsigned i = 0, e = LocalDefs.size(); i != e; ++i) {
166 unsigned Reg = LocalDefs[i];
167 if (Added.insert(Reg)) {
168 // If it's not live beyond end of the bundle, mark it dead.
169 bool isDead = DeadDefSet.count(Reg) || KilledDefSet.count(Reg);
170 MIB.addReg(Reg, getDefRegState(true) | getDeadRegState(isDead) |
171 getImplRegState(true));
175 for (unsigned i = 0, e = ExternUses.size(); i != e; ++i) {
176 unsigned Reg = ExternUses[i];
177 bool isKill = KilledUseSet.count(Reg);
178 bool isUndef = UndefUseSet.count(Reg);
179 MIB.addReg(Reg, getKillRegState(isKill) | getUndefRegState(isUndef) |
180 getImplRegState(true));
184 /// finalizeBundle - Same functionality as the previous finalizeBundle except
185 /// the last instruction in the bundle is not provided as an input. This is
186 /// used in cases where bundles are pre-determined by marking instructions
187 /// with 'InsideBundle' marker. It returns the MBB instruction iterator that
188 /// points to the end of the bundle.
189 MachineBasicBlock::instr_iterator
190 llvm::finalizeBundle(MachineBasicBlock &MBB,
191 MachineBasicBlock::instr_iterator FirstMI) {
192 MachineBasicBlock::instr_iterator E = MBB.instr_end();
193 MachineBasicBlock::instr_iterator LastMI = llvm::next(FirstMI);
194 while (LastMI != E && LastMI->isInsideBundle())
196 finalizeBundle(MBB, FirstMI, LastMI);