[mips] Move initGlobalBaseReg to MipsFunctionInfo. NFC

[Petar.Avramovic]

Summary

Move initGlobalBaseReg from MipsSEDAGToDAGISel to MipsFunctionInfo.
This way functions used for handling position independent code during
instruction selection, getGlobalBaseReg and initGlobalBaseReg,
end up in same class.

[atanasyan]

LGTM

lib/Target/Mips/MipsMachineFunction.h

public:
   ~MipsFunctionInfo() override;
 
   unsigned getSRetReturnReg() const { return SRetReturnReg; }
   void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
 
   bool globalBaseRegSet() const;
   unsigned getGlobalBaseReg();
 
+  // Insert instructions to initialize the global base register in the
+  // first MBB of the function.
+  void initGlobalBaseReg();
+
   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
   void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
 
   bool hasByvalArg() const { return HasByvalArg; }
   void setFormalArgInfo(unsigned Size, bool HasByval) {
     IncomingArgSize = Size;
     HasByvalArg = HasByval;
   }

lib/Target/Mips/MipsMachineFunction.cpp

 
 unsigned MipsFunctionInfo::getGlobalBaseReg() {
   if (!GlobalBaseReg)
     GlobalBaseReg =
         MF.getRegInfo().createVirtualRegister(&getGlobalBaseRegClass(MF));
   return GlobalBaseReg;
 }
 
+void MipsFunctionInfo::initGlobalBaseReg() {
+  if (!GlobalBaseReg)
+    return;
+
+  MachineBasicBlock &MBB = MF.front();
+  MachineBasicBlock::iterator I = MBB.begin();
+  MachineRegisterInfo &RegInfo = MF.getRegInfo();
+  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
+  DebugLoc DL;
+  unsigned V0, V1;
+  const TargetRegisterClass *RC;
+  const MipsABIInfo &ABI =
+      static_cast<const MipsTargetMachine &>(MF.getTarget()).getABI();
+  RC = (ABI.IsN64()) ? &Mips::GPR64RegClass : &Mips::GPR32RegClass;
+
+  V0 = RegInfo.createVirtualRegister(RC);
+  V1 = RegInfo.createVirtualRegister(RC);
+
+  if (ABI.IsN64()) {
+    MF.getRegInfo().addLiveIn(Mips::T9_64);
+    MBB.addLiveIn(Mips::T9_64);
+
+    // lui $v0, %hi(%neg(%gp_rel(fname)))
+    // daddu $v1, $v0, $t9
+    // daddiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname)))
+    const GlobalValue *FName = &MF.getFunction();
+    BuildMI(MBB, I, DL, TII.get(Mips::LUi64), V0)
+        .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI);
+    BuildMI(MBB, I, DL, TII.get(Mips::DADDu), V1).addReg(V0)
+        .addReg(Mips::T9_64);
+    BuildMI(MBB, I, DL, TII.get(Mips::DADDiu), GlobalBaseReg).addReg(V1)
+        .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO);
+    return;
+  }
+
+  if (!MF.getTarget().isPositionIndependent()) {
+    // Set global register to __gnu_local_gp.
+    //
+    // lui   $v0, %hi(__gnu_local_gp)
+    // addiu $globalbasereg, $v0, %lo(__gnu_local_gp)
+    BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0)
+        .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_HI);
+    BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V0)
+        .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_LO);
+    return;
+  }
+
+  MF.getRegInfo().addLiveIn(Mips::T9);
+  MBB.addLiveIn(Mips::T9);
+
+  if (ABI.IsN32()) {
+    // lui $v0, %hi(%neg(%gp_rel(fname)))
+    // addu $v1, $v0, $t9
+    // addiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname)))
+    const GlobalValue *FName = &MF.getFunction();
+    BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0)
+        .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI);
+    BuildMI(MBB, I, DL, TII.get(Mips::ADDu), V1).addReg(V0).addReg(Mips::T9);
+    BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V1)
+        .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO);
+    return;
+  }
+
+  assert(ABI.IsO32());
+
+  // For O32 ABI, the following instruction sequence is emitted to initialize
+  // the global base register:
+  //
+  //  0. lui   $2, %hi(_gp_disp)
+  //  1. addiu $2, $2, %lo(_gp_disp)
+  //  2. addu  $globalbasereg, $2, $t9
+  //
+  // We emit only the last instruction here.
+  //
+  // GNU linker requires that the first two instructions appear at the beginning
+  // of a function and no instructions be inserted before or between them.
+  // The two instructions are emitted during lowering to MC layer in order to
+  // avoid any reordering.
+  //
+  // Register $2 (Mips::V0) is added to the list of live-in registers to ensure
+  // the value instruction 1 (addiu) defines is valid when instruction 2 (addu)
+  // reads it.
+  MF.getRegInfo().addLiveIn(Mips::V0);
+  MBB.addLiveIn(Mips::V0);
+  BuildMI(MBB, I, DL, TII.get(Mips::ADDu), GlobalBaseReg)
+      .addReg(Mips::V0).addReg(Mips::T9);
+}
+
 void MipsFunctionInfo::createEhDataRegsFI() {
   const TargetRegisterInfo &TRI = *MF.getSubtarget().getRegisterInfo();
   for (int I = 0; I < 4; ++I) {
     const TargetRegisterClass &RC =
         static_cast<const MipsTargetMachine &>(MF.getTarget()).getABI().IsN64()
             ? Mips::GPR64RegClass
             : Mips::GPR32RegClass;
 

lib/Target/Mips/MipsSEISelDAGToDAG.h

private:
   /// Select constant vector splats whose value is a run of set bits
   /// starting at bit zero.
   bool selectVSplatMaskR(SDValue N, SDValue &Imm) const override;
 
   bool trySelect(SDNode *Node) override;
 
   void processFunctionAfterISel(MachineFunction &MF) override;
 
-  // Insert instructions to initialize the global base register in the
-  // first MBB of the function.
-  void initGlobalBaseReg(MachineFunction &MF);
-
   bool SelectInlineAsmMemoryOperand(const SDValue &Op,
                                     unsigned ConstraintID,
                                     std::vector<SDValue> &OutOps) override;
 };
 
 FunctionPass *createMipsSEISelDag(MipsTargetMachine &TM,
                                   CodeGenOpt::Level OptLevel);
 }
 
 #endif

lib/Target/Mips/MipsSEISelDAGToDAG.cpp

if (!MRI->getRegClass(MO.getReg())->contains(ZeroReg))
       continue;
 
     MO.setReg(ZeroReg);
   }
 
   return true;
 }
 
-void MipsSEDAGToDAGISel::initGlobalBaseReg(MachineFunction &MF) {
-  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
-
-  if (!MipsFI->globalBaseRegSet())
-    return;
-
-  MachineBasicBlock &MBB = MF.front();
-  MachineBasicBlock::iterator I = MBB.begin();
-  MachineRegisterInfo &RegInfo = MF.getRegInfo();
-  const TargetInstrInfo &TII = *Subtarget->getInstrInfo();
-  DebugLoc DL;
-  unsigned V0, V1, GlobalBaseReg = MipsFI->getGlobalBaseReg();
-  const TargetRegisterClass *RC;
-  const MipsABIInfo &ABI = static_cast<const MipsTargetMachine &>(TM).getABI();
-  RC = (ABI.IsN64()) ? &Mips::GPR64RegClass : &Mips::GPR32RegClass;
-
-  V0 = RegInfo.createVirtualRegister(RC);
-  V1 = RegInfo.createVirtualRegister(RC);
-
-  if (ABI.IsN64()) {
-    MF.getRegInfo().addLiveIn(Mips::T9_64);
-    MBB.addLiveIn(Mips::T9_64);
-
-    // lui $v0, %hi(%neg(%gp_rel(fname)))
-    // daddu $v1, $v0, $t9
-    // daddiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname)))
-    const GlobalValue *FName = &MF.getFunction();
-    BuildMI(MBB, I, DL, TII.get(Mips::LUi64), V0)
-      .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI);
-    BuildMI(MBB, I, DL, TII.get(Mips::DADDu), V1).addReg(V0)
-      .addReg(Mips::T9_64);
-    BuildMI(MBB, I, DL, TII.get(Mips::DADDiu), GlobalBaseReg).addReg(V1)
-      .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO);
-    return;
-  }
-
-  if (!MF.getTarget().isPositionIndependent()) {
-    // Set global register to __gnu_local_gp.
-    //
-    // lui   $v0, %hi(__gnu_local_gp)
-    // addiu $globalbasereg, $v0, %lo(__gnu_local_gp)
-    BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0)
-      .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_HI);
-    BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V0)
-      .addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_LO);
-    return;
-  }
-
-  MF.getRegInfo().addLiveIn(Mips::T9);
-  MBB.addLiveIn(Mips::T9);
-
-  if (ABI.IsN32()) {
-    // lui $v0, %hi(%neg(%gp_rel(fname)))
-    // addu $v1, $v0, $t9
-    // addiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname)))
-    const GlobalValue *FName = &MF.getFunction();
-    BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0)
-      .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI);
-    BuildMI(MBB, I, DL, TII.get(Mips::ADDu), V1).addReg(V0).addReg(Mips::T9);
-    BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V1)
-      .addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO);
-    return;
-  }
-
-  assert(ABI.IsO32());
-
-  // For O32 ABI, the following instruction sequence is emitted to initialize
-  // the global base register:
-  //
-  //  0. lui   $2, %hi(_gp_disp)
-  //  1. addiu $2, $2, %lo(_gp_disp)
-  //  2. addu  $globalbasereg, $2, $t9
-  //
-  // We emit only the last instruction here.
-  //
-  // GNU linker requires that the first two instructions appear at the beginning
-  // of a function and no instructions be inserted before or between them.
-  // The two instructions are emitted during lowering to MC layer in order to
-  // avoid any reordering.
-  //
-  // Register $2 (Mips::V0) is added to the list of live-in registers to ensure
-  // the value instruction 1 (addiu) defines is valid when instruction 2 (addu)
-  // reads it.
-  MF.getRegInfo().addLiveIn(Mips::V0);
-  MBB.addLiveIn(Mips::V0);
-  BuildMI(MBB, I, DL, TII.get(Mips::ADDu), GlobalBaseReg)
-    .addReg(Mips::V0).addReg(Mips::T9);
-}
-
 void MipsSEDAGToDAGISel::processFunctionAfterISel(MachineFunction &MF) {
-  initGlobalBaseReg(MF);
+  MF.getInfo<MipsFunctionInfo>()->initGlobalBaseReg();
 
   MachineRegisterInfo *MRI = &MF.getRegInfo();
 
   for (auto &MBB: MF) {
     for (auto &MI: MBB) {
       switch (MI.getOpcode()) {
       case Mips::RDDSP:
         addDSPCtrlRegOperands(false, MI, MF);