1 files changed, 264 insertions, 6 deletions

diff --git a/lib/Target/ARM/ARMInstructionSelector.cpp b/lib/Target/ARM/ARMInstructionSelector.cpp
index 2bdbe4fca3de..8d224d6a70fa 100644
--- a/lib/Target/ARM/ARMInstructionSelector.cpp
+++ b/lib/Target/ARM/ARMInstructionSelector.cpp
@@ -54,9 +54,21 @@ static bool selectCopy(MachineInstr &I, const TargetInstrInfo &TII,
            DstSize <= SrcSize)) &&
          "Copy with different width?!");
 
-  assert(RegBank->getID() == ARM::GPRRegBankID && "Unsupported reg bank");
+  assert((RegBank->getID() == ARM::GPRRegBankID ||
+          RegBank->getID() == ARM::FPRRegBankID) &&
+         "Unsupported reg bank");
+
   const TargetRegisterClass *RC = &ARM::GPRRegClass;
 
+  if (RegBank->getID() == ARM::FPRRegBankID) {
+    if (DstSize == 32)
+      RC = &ARM::SPRRegClass;
+    else if (DstSize == 64)
+      RC = &ARM::DPRRegClass;
+    else
+      llvm_unreachable("Unsupported destination size");
+  }
+
   // No need to constrain SrcReg. It will get constrained when
   // we hit another of its uses or its defs.
   // Copies do not have constraints.
@@ -68,6 +80,146 @@ static bool selectCopy(MachineInstr &I, const TargetInstrInfo &TII,
   return true;
 }
 
+static bool selectFAdd(MachineInstrBuilder &MIB, const ARMBaseInstrInfo &TII,
+                       MachineRegisterInfo &MRI) {
+  assert(TII.getSubtarget().hasVFP2() && "Can't select fp add without vfp");
+
+  LLT Ty = MRI.getType(MIB->getOperand(0).getReg());
+  unsigned ValSize = Ty.getSizeInBits();
+
+  if (ValSize == 32) {
+    if (TII.getSubtarget().useNEONForSinglePrecisionFP())
+      return false;
+    MIB->setDesc(TII.get(ARM::VADDS));
+  } else {
+    assert(ValSize == 64 && "Unsupported size for floating point value");
+    if (TII.getSubtarget().isFPOnlySP())
+      return false;
+    MIB->setDesc(TII.get(ARM::VADDD));
+  }
+  MIB.add(predOps(ARMCC::AL));
+
+  return true;
+}
+
+static bool selectSequence(MachineInstrBuilder &MIB,
+                           const ARMBaseInstrInfo &TII,
+                           MachineRegisterInfo &MRI,
+                           const TargetRegisterInfo &TRI,
+                           const RegisterBankInfo &RBI) {
+  assert(TII.getSubtarget().hasVFP2() && "Can't select sequence without VFP");
+
+  // We only support G_SEQUENCE as a way to stick together two scalar GPRs
+  // into one DPR.
+  unsigned VReg0 = MIB->getOperand(0).getReg();
+  (void)VReg0;
+  assert(MRI.getType(VReg0).getSizeInBits() == 64 &&
+         RBI.getRegBank(VReg0, MRI, TRI)->getID() == ARM::FPRRegBankID &&
+         "Unsupported operand for G_SEQUENCE");
+  unsigned VReg1 = MIB->getOperand(1).getReg();
+  (void)VReg1;
+  assert(MRI.getType(VReg1).getSizeInBits() == 32 &&
+         RBI.getRegBank(VReg1, MRI, TRI)->getID() == ARM::GPRRegBankID &&
+         "Unsupported operand for G_SEQUENCE");
+  unsigned VReg2 = MIB->getOperand(3).getReg();
+  (void)VReg2;
+  assert(MRI.getType(VReg2).getSizeInBits() == 32 &&
+         RBI.getRegBank(VReg2, MRI, TRI)->getID() == ARM::GPRRegBankID &&
+         "Unsupported operand for G_SEQUENCE");
+
+  // Remove the operands corresponding to the offsets.
+  MIB->RemoveOperand(4);
+  MIB->RemoveOperand(2);
+
+  MIB->setDesc(TII.get(ARM::VMOVDRR));
+  MIB.add(predOps(ARMCC::AL));
+
+  return true;
+}
+
+static bool selectExtract(MachineInstrBuilder &MIB, const ARMBaseInstrInfo &TII,
+                          MachineRegisterInfo &MRI,
+                          const TargetRegisterInfo &TRI,
+                          const RegisterBankInfo &RBI) {
+  assert(TII.getSubtarget().hasVFP2() && "Can't select extract without VFP");
+
+  // We only support G_EXTRACT as a way to break up one DPR into two GPRs.
+  unsigned VReg0 = MIB->getOperand(0).getReg();
+  (void)VReg0;
+  assert(MRI.getType(VReg0).getSizeInBits() == 32 &&
+         RBI.getRegBank(VReg0, MRI, TRI)->getID() == ARM::GPRRegBankID &&
+         "Unsupported operand for G_EXTRACT");
+  unsigned VReg1 = MIB->getOperand(1).getReg();
+  (void)VReg1;
+  assert(MRI.getType(VReg1).getSizeInBits() == 64 &&
+         RBI.getRegBank(VReg1, MRI, TRI)->getID() == ARM::FPRRegBankID &&
+         "Unsupported operand for G_EXTRACT");
+  assert(MIB->getOperand(2).getImm() % 32 == 0 &&
+         "Unsupported operand for G_EXTRACT");
+
+  // Remove the operands corresponding to the offsets.
+  MIB->getOperand(2).setImm(MIB->getOperand(2).getImm() / 32);
+
+  MIB->setDesc(TII.get(ARM::VGETLNi32));
+  MIB.add(predOps(ARMCC::AL));
+
+  return true;
+}
+
+/// Select the opcode for simple extensions (that translate to a single SXT/UXT
+/// instruction). Extension operations more complicated than that should not
+/// invoke this. Returns the original opcode if it doesn't know how to select a
+/// better one.
+static unsigned selectSimpleExtOpc(unsigned Opc, unsigned Size) {
+  using namespace TargetOpcode;
+
+  if (Size != 8 && Size != 16)
+    return Opc;
+
+  if (Opc == G_SEXT)
+    return Size == 8 ? ARM::SXTB : ARM::SXTH;
+
+  if (Opc == G_ZEXT)
+    return Size == 8 ? ARM::UXTB : ARM::UXTH;
+
+  return Opc;
+}
+
+/// Select the opcode for simple loads and stores. For types smaller than 32
+/// bits, the value will be zero extended. Returns the original opcode if it
+/// doesn't know how to select a better one.
+static unsigned selectLoadStoreOpCode(unsigned Opc, unsigned RegBank,
+                                      unsigned Size) {
+  bool isStore = Opc == TargetOpcode::G_STORE;
+
+  if (RegBank == ARM::GPRRegBankID) {
+    switch (Size) {
+    case 1:
+    case 8:
+      return isStore ? ARM::STRBi12 : ARM::LDRBi12;
+    case 16:
+      return isStore ? ARM::STRH : ARM::LDRH;
+    case 32:
+      return isStore ? ARM::STRi12 : ARM::LDRi12;
+    default:
+      return Opc;
+    }
+  }
+
+  if (RegBank == ARM::FPRRegBankID) {
+    switch (Size) {
+    case 32:
+      return isStore ? ARM::VSTRS : ARM::VLDRS;
+    case 64:
+      return isStore ? ARM::VSTRD : ARM::VLDRD;
+    default:
+      return Opc;
+    }
+  }
+
+  return Opc;
+}
+
 bool ARMInstructionSelector::select(MachineInstr &I) const {
   assert(I.getParent() && "Instruction should be in a basic block!");
   assert(I.getParent()->getParent() && "Instruction should be in a function!");
@@ -84,23 +236,129 @@ bool ARMInstructionSelector::select(MachineInstr &I) const {
   }
 
   MachineInstrBuilder MIB{MF, I};
+  bool isSExt = false;
 
   using namespace TargetOpcode;
   switch (I.getOpcode()) {
+  case G_SEXT:
+    isSExt = true;
+    LLVM_FALLTHROUGH;
+  case G_ZEXT: {
+    LLT DstTy = MRI.getType(I.getOperand(0).getReg());
+    // FIXME: Smaller destination sizes coming soon!
+    if (DstTy.getSizeInBits() != 32) {
+      DEBUG(dbgs() << "Unsupported destination size for extension");
+      return false;
+    }
+
+    LLT SrcTy = MRI.getType(I.getOperand(1).getReg());
+    unsigned SrcSize = SrcTy.getSizeInBits();
+    switch (SrcSize) {
+    case 1: {
+      // ZExt boils down to & 0x1; for SExt we also subtract that from 0
+      I.setDesc(TII.get(ARM::ANDri));
+      MIB.addImm(1).add(predOps(ARMCC::AL)).add(condCodeOp());
+
+      if (isSExt) {
+        unsigned SExtResult = I.getOperand(0).getReg();
+
+        // Use a new virtual register for the result of the AND
+        unsigned AndResult = MRI.createVirtualRegister(&ARM::GPRRegClass);
+        I.getOperand(0).setReg(AndResult);
+
+        auto InsertBefore = std::next(I.getIterator());
+        auto SubI =
+            BuildMI(MBB, InsertBefore, I.getDebugLoc(), TII.get(ARM::RSBri))
+                .addDef(SExtResult)
+                .addUse(AndResult)
+                .addImm(0)
+                .add(predOps(ARMCC::AL))
+                .add(condCodeOp());
+        if (!constrainSelectedInstRegOperands(*SubI, TII, TRI, RBI))
+          return false;
+      }
+      break;
+    }
+    case 8:
+    case 16: {
+      unsigned NewOpc = selectSimpleExtOpc(I.getOpcode(), SrcSize);
+      if (NewOpc == I.getOpcode())
+        return false;
+      I.setDesc(TII.get(NewOpc));
+      MIB.addImm(0).add(predOps(ARMCC::AL));
+      break;
+    }
+    default:
+      DEBUG(dbgs() << "Unsupported source size for extension");
+      return false;
+    }
+    break;
+  }
   case G_ADD:
+  case G_GEP:
     I.setDesc(TII.get(ARM::ADDrr));
-    AddDefaultCC(AddDefaultPred(MIB));
+    MIB.add(predOps(ARMCC::AL)).add(condCodeOp());
+    break;
+  case G_FADD:
+    if (!selectFAdd(MIB, TII, MRI))
+      return false;
     break;
   case G_FRAME_INDEX:
     // Add 0 to the given frame index and hope it will eventually be folded into
     // the user(s).
     I.setDesc(TII.get(ARM::ADDri));
-    AddDefaultCC(AddDefaultPred(MIB.addImm(0)));
+    MIB.addImm(0).add(predOps(ARMCC::AL)).add(condCodeOp());
     break;
-  case G_LOAD:
-    I.setDesc(TII.get(ARM::LDRi12));
-    AddDefaultPred(MIB.addImm(0));
+  case G_CONSTANT: {
+    unsigned Reg = I.getOperand(0).getReg();
+    if (MRI.getType(Reg).getSizeInBits() != 32)
+      return false;
+
+    assert(RBI.getRegBank(Reg, MRI, TRI)->getID() == ARM::GPRRegBankID &&
+           "Expected constant to live in a GPR");
+    I.setDesc(TII.get(ARM::MOVi));
+    MIB.add(predOps(ARMCC::AL)).add(condCodeOp());
+    break;
+  }
+  case G_STORE:
+  case G_LOAD: {
+    const auto &MemOp = **I.memoperands_begin();
+    if (MemOp.getOrdering() != AtomicOrdering::NotAtomic) {
+      DEBUG(dbgs() << "Atomic load/store not supported yet\n");
+      return false;
+    }
+
+    unsigned Reg = I.getOperand(0).getReg();
+    unsigned RegBank = RBI.getRegBank(Reg, MRI, TRI)->getID();
+
+    LLT ValTy = MRI.getType(Reg);
+    const auto ValSize = ValTy.getSizeInBits();
+
+    assert((ValSize != 64 || TII.getSubtarget().hasVFP2()) &&
+           "Don't know how to load/store 64-bit value without VFP");
+
+    const auto NewOpc = selectLoadStoreOpCode(I.getOpcode(), RegBank, ValSize);
+    if (NewOpc == G_LOAD || NewOpc == G_STORE)
+      return false;
+
+    I.setDesc(TII.get(NewOpc));
+
+    if (NewOpc == ARM::LDRH || NewOpc == ARM::STRH)
+      // LDRH has a funny addressing mode (there's already a FIXME for it).
+      MIB.addReg(0);
+    MIB.addImm(0).add(predOps(ARMCC::AL));
+    break;
+  }
+  case G_SEQUENCE: {
+    if (!selectSequence(MIB, TII, MRI, TRI, RBI))
+      return false;
     break;
+  }
+  case G_EXTRACT: {
+    if (!selectExtract(MIB, TII, MRI, TRI, RBI))
+      return false;
+    break;
+  }
   default:
     return false;
   }