RemoveLoadsIntoFakeUses.cpp Source File (original) (raw)

39using namespace llvm;

41#define DEBUG_TYPE "remove-loads-into-fake-uses"

43 STATISTIC(NumLoadsDeleted, "Number of dead load instructions deleted");

44 STATISTIC(NumFakeUsesDeleted, "Number of FAKE_USE instructions deleted");

47public:

48 static char ID;

65 return "Remove Loads Into Fake Uses";

66 }

69};

79 "Remove Loads Into Fake Uses", false, false)

100 return PA;

101}

102

104

105

107 return false;

108

110 return false;

111

112 bool AnyChanges = false;

113

119

123 RegFakeUses.clear();

125

127 if (MI.isFakeUse()) {

128 if (MI.getNumOperands() == 0 || .getOperand(0).isReg())

129 continue;

130

131

133

134

135 continue;

136 }

137

138

139

140 if (MI.getRestoreSize(TII)) {

141 Register Reg = MI.getOperand(0).getReg();

142

144 continue;

145

146

147

148

149

150

151

154 if (FakeUse->readsRegister(Reg, TRI)) {

155 FakeUsesToDelete.insert(FakeUse);

156 RegFakeUses.erase(&FakeUse);

157 }

158 }

159 if (!FakeUsesToDelete.empty()) {

160 LLVM_DEBUG(dbgs() << "RemoveLoadsIntoFakeUses: DELETING: " << MI);

161

162

163

164 MI.eraseFromParent();

165 AnyChanges = true;

166 ++NumLoadsDeleted;

167 for (MachineInstr *FakeUse : FakeUsesToDelete) {

169 << "RemoveLoadsIntoFakeUses: DELETING: " << *FakeUse);

170 FakeUse->eraseFromParent();

171 }

172 NumFakeUsesDeleted += FakeUsesToDelete.size();

173 }

174 continue;

175 }

176

177

178

179

180 if (!RegFakeUses.empty()) {

182 if (!MO.isReg())

183 continue;

185

186

187

189 if (FakeUse->readsRegister(Reg, TRI))

190 RegFakeUses.erase(&FakeUse);

191 }

192 }

194 }

195 }

196

197 return AnyChanges;

198}

unsigned const MachineRegisterInfo * MRI

const TargetInstrInfo & TII

#define INITIALIZE_PASS_END(passName, arg, name, cfg, analysis)

#define INITIALIZE_PASS_BEGIN(passName, arg, name, cfg, analysis)

This file builds on the ADT/GraphTraits.h file to build a generic graph post order iterator.

This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...

#define STATISTIC(VARNAME, DESC)

bool runOnMachineFunction(MachineFunction &MF) override

runOnMachineFunction - This method must be overloaded to perform the desired machine code transformat...

Definition RemoveLoadsIntoFakeUses.cpp:83

RemoveLoadsIntoFakeUsesLegacy()

Definition RemoveLoadsIntoFakeUses.cpp:50

StringRef getPassName() const override

getPassName - Return a nice clean name for a pass.

Definition RemoveLoadsIntoFakeUses.cpp:64

MachineFunctionProperties getRequiredProperties() const override

Definition RemoveLoadsIntoFakeUses.cpp:60

void getAnalysisUsage(AnalysisUsage &AU) const override

getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.

Definition RemoveLoadsIntoFakeUses.cpp:55

static char ID

Definition RemoveLoadsIntoFakeUses.cpp:48

Represent the analysis usage information of a pass.

LLVM_ABI void setPreservesCFG()

This function should be called by the pass, iff they do not:

Represents analyses that only rely on functions' control flow.

bool skipFunction(const Function &F) const

Optional passes call this function to check whether the pass should be skipped.

A set of physical registers with utility functions to track liveness when walking backward/forward th...

void stepBackward(const MachineInstr &MI)

Simulates liveness when stepping backwards over an instruction(bundle).

void init(const TargetRegisterInfo &TRI)

(re-)initializes and clears the set.

bool available(const MachineRegisterInfo &MRI, MCRegister Reg) const

Returns true if register Reg and no aliasing register is in the set.

void addLiveOuts(const MachineBasicBlock &MBB)

Adds all live-out registers of basic block MBB.

A set of register units used to track register liveness.

An RAII based helper class to modify MachineFunctionProperties when running pass.

MachineFunctionPass(char &ID)

void getAnalysisUsage(AnalysisUsage &AU) const override

getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.

Properties which a MachineFunction may have at a given point in time.

bool useDebugInstrRef() const

Returns true if the function's variable locations are tracked with instruction referencing.

const TargetSubtargetInfo & getSubtarget() const

getSubtarget - Return the subtarget for which this machine code is being compiled.

MachineRegisterInfo & getRegInfo()

getRegInfo - Return information about the registers currently in use.

Representation of each machine instruction.

MachineOperand class - Representation of each machine instruction operand.

MachineRegisterInfo - Keep track of information for virtual and physical registers,...

static LLVM_ABI PassRegistry * getPassRegistry()

getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...

A set of analyses that are preserved following a run of a transformation pass.

static PreservedAnalyses all()

Construct a special preserved set that preserves all passes.

Wrapper class representing virtual and physical registers.

PreservedAnalyses run(MachineFunction &MF, MachineFunctionAnalysisManager &MFAM)

Definition RemoveLoadsIntoFakeUses.cpp:91

Implements a dense probed hash-table based set with some number of buckets stored inline.

iterator erase(const_iterator CI)

void push_back(const T &Elt)

This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.

StringRef - Represent a constant reference to a string, i.e.

TargetInstrInfo - Interface to description of machine instruction set.

TargetRegisterInfo base class - We assume that the target defines a static array of TargetRegisterDes...

TargetSubtargetInfo - Generic base class for all target subtargets.

std::pair< iterator, bool > insert(const ValueT &V)

This is an optimization pass for GlobalISel generic memory operations.

iterator_range< early_inc_iterator_impl< detail::IterOfRange< RangeT > > > make_early_inc_range(RangeT &&Range)

Make a range that does early increment to allow mutation of the underlying range without disrupting i...

LLVM_ABI char & RemoveLoadsIntoFakeUsesID

RemoveLoadsIntoFakeUses pass.

Definition RemoveLoadsIntoFakeUses.cpp:76

iterator_range< po_iterator< T > > post_order(const T &G)

AnalysisManager< MachineFunction > MachineFunctionAnalysisManager

LLVM_ABI PreservedAnalyses getMachineFunctionPassPreservedAnalyses()

Returns the minimum set of Analyses that all machine function passes must preserve.

auto reverse(ContainerTy &&C)

LLVM_ABI void initializeRemoveLoadsIntoFakeUsesLegacyPass(PassRegistry &)

LLVM_ABI raw_ostream & dbgs()

dbgs() - This returns a reference to a raw_ostream for debugging messages.

bool run(MachineFunction &MF)

Definition RemoveLoadsIntoFakeUses.cpp:103