1 files changed, 225 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/Mips/Mips16ISelDAGToDAG.cpp b/contrib/llvm-project/llvm/lib/Target/Mips/Mips16ISelDAGToDAG.cpp
new file mode 100644
index 000000000000..3ab4f1e064da
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Target/Mips/Mips16ISelDAGToDAG.cpp
@@ -0,0 +1,225 @@
+//===-- Mips16ISelDAGToDAG.cpp - A Dag to Dag Inst Selector for Mips16 ----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Subclass of MipsDAGToDAGISel specialized for mips16.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Mips16ISelDAGToDAG.h"
+#include "MCTargetDesc/MipsBaseInfo.h"
+#include "Mips.h"
+#include "MipsMachineFunction.h"
+#include "MipsRegisterInfo.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/SelectionDAGNodes.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetMachine.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "mips-isel"
+
+bool Mips16DAGToDAGISel::runOnMachineFunction(MachineFunction &MF) {
+  Subtarget = &static_cast<const MipsSubtarget &>(MF.getSubtarget());
+  if (!Subtarget->inMips16Mode())
+    return false;
+  return MipsDAGToDAGISel::runOnMachineFunction(MF);
+}
+/// Select multiply instructions.
+std::pair<SDNode *, SDNode *>
+Mips16DAGToDAGISel::selectMULT(SDNode *N, unsigned Opc, const SDLoc &DL, EVT Ty,
+                               bool HasLo, bool HasHi) {
+  SDNode *Lo = nullptr, *Hi = nullptr;
+  SDNode *Mul = CurDAG->getMachineNode(Opc, DL, MVT::Glue, N->getOperand(0),
+                                       N->getOperand(1));
+  SDValue InFlag = SDValue(Mul, 0);
+
+  if (HasLo) {
+    unsigned Opcode = Mips::Mflo16;
+    Lo = CurDAG->getMachineNode(Opcode, DL, Ty, MVT::Glue, InFlag);
+    InFlag = SDValue(Lo, 1);
+  }
+  if (HasHi) {
+    unsigned Opcode = Mips::Mfhi16;
+    Hi = CurDAG->getMachineNode(Opcode, DL, Ty, InFlag);
+  }
+  return std::make_pair(Lo, Hi);
+}
+
+void Mips16DAGToDAGISel::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, V2, GlobalBaseReg = MipsFI->getGlobalBaseReg();
+  const TargetRegisterClass *RC = &Mips::CPU16RegsRegClass;
+
+  V0 = RegInfo.createVirtualRegister(RC);
+  V1 = RegInfo.createVirtualRegister(RC);
+  V2 = RegInfo.createVirtualRegister(RC);
+
+
+  BuildMI(MBB, I, DL, TII.get(Mips::LiRxImmX16), V0)
+      .addExternalSymbol("_gp_disp", MipsII::MO_ABS_HI);
+  BuildMI(MBB, I, DL, TII.get(Mips::AddiuRxPcImmX16), V1)
+      .addExternalSymbol("_gp_disp", MipsII::MO_ABS_LO);
+
+  BuildMI(MBB, I, DL, TII.get(Mips::SllX16), V2).addReg(V0).addImm(16);
+  BuildMI(MBB, I, DL, TII.get(Mips::AdduRxRyRz16), GlobalBaseReg)
+      .addReg(V1)
+      .addReg(V2);
+}
+
+void Mips16DAGToDAGISel::processFunctionAfterISel(MachineFunction &MF) {
+  initGlobalBaseReg(MF);
+}
+
+bool Mips16DAGToDAGISel::selectAddr(bool SPAllowed, SDValue Addr, SDValue &Base,
+                                    SDValue &Offset) {
+  SDLoc DL(Addr);
+  EVT ValTy = Addr.getValueType();
+
+  // if Address is FI, get the TargetFrameIndex.
+  if (SPAllowed) {
+    if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
+      Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy);
+      Offset = CurDAG->getTargetConstant(0, DL, ValTy);
+      return true;
+    }
+  }
+  // on PIC code Load GA
+  if (Addr.getOpcode() == MipsISD::Wrapper) {
+    Base = Addr.getOperand(0);
+    Offset = Addr.getOperand(1);
+    return true;
+  }
+  if (!TM.isPositionIndependent()) {
+    if ((Addr.getOpcode() == ISD::TargetExternalSymbol ||
+         Addr.getOpcode() == ISD::TargetGlobalAddress))
+      return false;
+  }
+  // Addresses of the form FI+const or FI|const
+  if (CurDAG->isBaseWithConstantOffset(Addr)) {
+    ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1));
+    if (isInt<16>(CN->getSExtValue())) {
+      // If the first operand is a FI, get the TargetFI Node
+      if (SPAllowed) {
+        if (FrameIndexSDNode *FIN =
+                dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) {
+          Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy);
+          Offset = CurDAG->getTargetConstant(CN->getZExtValue(), DL, ValTy);
+          return true;
+        }
+      }
+
+      Base = Addr.getOperand(0);
+      Offset = CurDAG->getTargetConstant(CN->getZExtValue(), DL, ValTy);
+      return true;
+    }
+  }
+  // Operand is a result from an ADD.
+  if (Addr.getOpcode() == ISD::ADD) {
+    // When loading from constant pools, load the lower address part in
+    // the instruction itself. Example, instead of:
+    //  lui $2, %hi($CPI1_0)
+    //  addiu $2, $2, %lo($CPI1_0)
+    //  lwc1 $f0, 0($2)
+    // Generate:
+    //  lui $2, %hi($CPI1_0)
+    //  lwc1 $f0, %lo($CPI1_0)($2)
+    if (Addr.getOperand(1).getOpcode() == MipsISD::Lo ||
+        Addr.getOperand(1).getOpcode() == MipsISD::GPRel) {
+      SDValue Opnd0 = Addr.getOperand(1).getOperand(0);
+      if (isa<ConstantPoolSDNode>(Opnd0) || isa<GlobalAddressSDNode>(Opnd0) ||
+          isa<JumpTableSDNode>(Opnd0)) {
+        Base = Addr.getOperand(0);
+        Offset = Opnd0;
+        return true;
+      }
+    }
+  }
+  Base = Addr;
+  Offset = CurDAG->getTargetConstant(0, DL, ValTy);
+  return true;
+}
+
+bool Mips16DAGToDAGISel::selectAddr16(SDValue Addr, SDValue &Base,
+                                      SDValue &Offset) {
+  return selectAddr(false, Addr, Base, Offset);
+}
+
+bool Mips16DAGToDAGISel::selectAddr16SP(SDValue Addr, SDValue &Base,
+                                        SDValue &Offset) {
+  return selectAddr(true, Addr, Base, Offset);
+}
+
+/// Select instructions not customized! Used for
+/// expanded, promoted and normal instructions
+bool Mips16DAGToDAGISel::trySelect(SDNode *Node) {
+  unsigned Opcode = Node->getOpcode();
+  SDLoc DL(Node);
+
+  ///
+  // Instruction Selection not handled by the auto-generated
+  // tablegen selection should be handled here.
+  ///
+  EVT NodeTy = Node->getValueType(0);
+  unsigned MultOpc;
+
+  switch (Opcode) {
+  default:
+    break;
+
+  /// Mul with two results
+  case ISD::SMUL_LOHI:
+  case ISD::UMUL_LOHI: {
+    MultOpc = (Opcode == ISD::UMUL_LOHI ? Mips::MultuRxRy16 : Mips::MultRxRy16);
+    std::pair<SDNode *, SDNode *> LoHi =
+        selectMULT(Node, MultOpc, DL, NodeTy, true, true);
+    if (!SDValue(Node, 0).use_empty())
+      ReplaceUses(SDValue(Node, 0), SDValue(LoHi.first, 0));
+
+    if (!SDValue(Node, 1).use_empty())
+      ReplaceUses(SDValue(Node, 1), SDValue(LoHi.second, 0));
+
+    CurDAG->RemoveDeadNode(Node);
+    return true;
+  }
+
+  case ISD::MULHS:
+  case ISD::MULHU: {
+    MultOpc = (Opcode == ISD::MULHU ? Mips::MultuRxRy16 : Mips::MultRxRy16);
+    auto LoHi = selectMULT(Node, MultOpc, DL, NodeTy, false, true);
+    ReplaceNode(Node, LoHi.second);
+    return true;
+  }
+  }
+
+  return false;
+}
+
+FunctionPass *llvm::createMips16ISelDag(MipsTargetMachine &TM,
+                                        CodeGenOpt::Level OptLevel) {
+  return new Mips16DAGToDAGISel(TM, OptLevel);
+}