WebAssemblyPeephole.cpp Source File (original) (raw)

23using namespace llvm;

25#define DEBUG_TYPE "wasm-peephole"

28 "disable-wasm-fallthrough-return-opt", cl::Hidden,

29 cl::desc("WebAssembly: Disable fallthrough-return optimizations."),

32namespace {

34 StringRef getPassName() const override {

35 return "WebAssembly late peephole optimizer";

36 }

38 void getAnalysisUsage(AnalysisUsage &AU) const override {

40 AU.addRequired();

42 }

44 bool runOnMachineFunction(MachineFunction &MF) override;

46public:

47 static char ID;

48 WebAssemblyPeephole() : MachineFunctionPass(ID) {}

49};

50}

52char WebAssemblyPeephole::ID = 0;

54 "WebAssembly peephole optimizations", false, false)

57 return new WebAssemblyPeephole();

58}

65 if (OldReg == NewReg) {

67 Register NewReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));

71 }

73}

81 return false;

83 return false;

86 --End;

87 assert(End->getOpcode() == WebAssembly::END_FUNCTION);

88 --End;

89 if (&MI != &*End)

90 return false;

92 for (auto &MO : MI.explicit_operands()) {

97 unsigned CopyLocalOpc;

100 Register NewReg = MRI.createVirtualRegister(RegClass);

101 BuildMI(MBB, MI, MI.getDebugLoc(), TII.get(CopyLocalOpc), NewReg)

103 MO.setReg(NewReg);

105 }

106 }

107

108 MI.setDesc(TII.get(WebAssembly::FALLTHROUGH_RETURN));

109 return true;

110}

111

112bool WebAssemblyPeephole::runOnMachineFunction(MachineFunction &MF) {

114 dbgs() << "********** Peephole **********\n"

115 << "********** Function: " << MF.getName() << '\n';

116 });

117

119 WebAssemblyFunctionInfo &MFI = *MF.getInfo();

120 const auto &TII = *MF.getSubtarget().getInstrInfo();

121 const WebAssemblyTargetLowering &TLI =

122 *MF.getSubtarget().getTargetLowering();

123 auto &LibInfo =

124 getAnalysis().getTLI(MF.getFunction());

126

127 for (auto &MBB : MF)

128 for (auto &MI : MBB)

129 switch (MI.getOpcode()) {

130 default:

131 break;

132 case WebAssembly::CALL: {

133 MachineOperand &Op1 = MI.getOperand(1);

139 LibFunc Func;

140 if (LibInfo.getLibFunc(Name, Func)) {

141 const auto &Op2 = MI.getOperand(2);

142 if (!Op2.isReg())

144 "wrong signature, not consuming reg");

145 MachineOperand &MO = MI.getOperand(0);

147 Register NewReg = Op2.getReg();

148

149 if (MRI.getRegClass(NewReg) != MRI.getRegClass(OldReg))

151 "wrong signature, from/to mismatch");

153 }

154 }

155 }

156 break;

157 }

158

159 case WebAssembly::RETURN:

161 break;

162 }

163

165}

unsigned const MachineRegisterInfo * MRI

assert(UImm &&(UImm !=~static_cast< T >(0)) &&"Invalid immediate!")

const TargetInstrInfo & TII

Promote Memory to Register

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

This file provides WebAssembly-specific target descriptions.

This file declares WebAssembly-specific per-machine-function information.

static bool maybeRewriteToDrop(unsigned OldReg, unsigned NewReg, MachineOperand &MO, WebAssemblyFunctionInfo &MFI, MachineRegisterInfo &MRI)

If desirable, rewrite NewReg to a drop register.

Definition WebAssemblyPeephole.cpp:61

static bool maybeRewriteToFallthrough(MachineInstr &MI, MachineBasicBlock &MBB, const MachineFunction &MF, WebAssemblyFunctionInfo &MFI, MachineRegisterInfo &MRI, const WebAssemblyInstrInfo &TII)

Definition WebAssemblyPeephole.cpp:75

static cl::opt< bool > DisableWebAssemblyFallthroughReturnOpt("disable-wasm-fallthrough-return-opt", cl::Hidden, cl::desc("WebAssembly: Disable fallthrough-return optimizations."), cl::init(false))

This file declares the WebAssembly-specific subclass of TargetSubtarget.

This file contains the declaration of the WebAssembly-specific utility functions.

This file contains the entry points for global functions defined in the LLVM WebAssembly back-end.

AnalysisUsage & addRequired()

LLVM_ABI void setPreservesCFG()

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

FunctionPass class - This class is used to implement most global optimizations.

MachineInstrBundleIterator< MachineInstr > iterator

MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...

void getAnalysisUsage(AnalysisUsage &AU) const override

getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.

const TargetSubtargetInfo & getSubtarget() const

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

StringRef getName() const

getName - Return the name of the corresponding LLVM function.

MachineRegisterInfo & getRegInfo()

getRegInfo - Return information about the registers currently in use.

Function & getFunction()

Return the LLVM function that this machine code represents.

const MachineBasicBlock & back() const

Ty * getInfo()

getInfo - Keep track of various per-function pieces of information for backends that would like to do...

const MachineInstrBuilder & addReg(Register RegNo, unsigned flags=0, unsigned SubReg=0) const

Add a new virtual register operand.

Representation of each machine instruction.

MachineOperand class - Representation of each machine instruction operand.

void setIsDead(bool Val=true)

LLVM_ABI void setReg(Register Reg)

Change the register this operand corresponds to.

bool isSymbol() const

isSymbol - Tests if this is a MO_ExternalSymbol operand.

const char * getSymbolName() const

getReg - Returns the register number.

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

Wrapper class representing virtual and physical registers.

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

const char * getLibcallName(RTLIB::Libcall Call) const

Get the libcall routine name for the specified libcall.

This class is derived from MachineFunctionInfo and contains private WebAssembly-specific information ...

void stackifyVReg(MachineRegisterInfo &MRI, Register VReg)

bool isVRegStackified(Register VReg) const

unsigned getCopyOpcodeForRegClass(const TargetRegisterClass *RC)

Returns the appropriate copy opcode for the given register class.

initializer< Ty > init(const Ty &Val)

NodeAddr< FuncNode * > Func

This is an optimization pass for GlobalISel generic memory operations.

MachineInstrBuilder BuildMI(MachineFunction &MF, const MIMetadata &MIMD, const MCInstrDesc &MCID)

Builder interface. Specify how to create the initial instruction itself.

LLVM_ABI raw_ostream & dbgs()

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

LLVM_ABI void report_fatal_error(Error Err, bool gen_crash_diag=true)

FunctionPass * createWebAssemblyPeephole()