Add XCore backend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58838 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 506 insertions, 0 deletions

diff --git a/lib/Target/XCore/XCoreInstrInfo.cpp b/lib/Target/XCore/XCoreInstrInfo.cpp
new file mode 100644
index 0000000000..4d0f42a020
--- /dev/null
+++ b/lib/Target/XCore/XCoreInstrInfo.cpp
@@ -0,0 +1,506 @@
+//===- XCoreInstrInfo.cpp - XCore Instruction Information -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the XCore implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "XCoreMachineFunctionInfo.h"
+#include "XCoreInstrInfo.h"
+#include "XCore.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineLocation.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "XCoreGenInstrInfo.inc"
+#include "llvm/Support/Debug.h"
+
+namespace llvm {
+namespace XCore {
+
+  // XCore Condition Codes
+  enum CondCode {
+    COND_TRUE,
+    COND_FALSE,
+    COND_INVALID
+  };
+}
+}
+
+using namespace llvm;
+
+XCoreInstrInfo::XCoreInstrInfo(void)
+  : TargetInstrInfoImpl(XCoreInsts, array_lengthof(XCoreInsts)),
+    RI(*this) {
+}
+
+static bool isZeroImm(const MachineOperand &op) {
+  return op.isImm() && op.getImm() == 0;
+}
+
+/// Return true if the instruction is a register to register move and
+/// leave the source and dest operands in the passed parameters.
+///
+bool XCoreInstrInfo::isMoveInstr(const MachineInstr &MI,
+                                 unsigned &SrcReg, unsigned &DstReg) const {
+  // We look for 4 kinds of patterns here:
+  // add dst, src, 0
+  // sub dst, src, 0
+  // or dst, src, src
+  // and dst, src, src
+  if ((MI.getOpcode() == XCore::ADD_2rus || MI.getOpcode() == XCore::SUB_2rus)
+      && isZeroImm(MI.getOperand(2))) {
+    DstReg = MI.getOperand(0).getReg();
+    SrcReg = MI.getOperand(1).getReg();
+    return true;
+  } else if ((MI.getOpcode() == XCore::OR_3r || MI.getOpcode() == XCore::AND_3r)
+      && MI.getOperand(1).getReg() == MI.getOperand(2).getReg()) {
+    DstReg = MI.getOperand(0).getReg();
+    SrcReg = MI.getOperand(1).getReg();
+    return true;
+  }
+  return false;
+}
+
+/// isLoadFromStackSlot - If the specified machine instruction is a direct
+/// load from a stack slot, return the virtual or physical register number of
+/// the destination along with the FrameIndex of the loaded stack slot.  If
+/// not, return 0.  This predicate must return 0 if the instruction has
+/// any side effects other than loading from the stack slot.
+unsigned
+XCoreInstrInfo::isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const{
+  int Opcode = MI->getOpcode();
+  if (Opcode == XCore::LDWSP_ru6 || Opcode == XCore::LDWSP_lru6) 
+  {
+    if ((MI->getOperand(1).isFI()) && // is a stack slot
+        (MI->getOperand(2).isImm()) &&  // the imm is zero
+        (isZeroImm(MI->getOperand(2)))) 
+    {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+  return 0;
+}
+  
+  /// isStoreToStackSlot - If the specified machine instruction is a direct
+  /// store to a stack slot, return the virtual or physical register number of
+  /// the source reg along with the FrameIndex of the loaded stack slot.  If
+  /// not, return 0.  This predicate must return 0 if the instruction has
+  /// any side effects other than storing to the stack slot.
+unsigned
+XCoreInstrInfo::isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const {
+  int Opcode = MI->getOpcode();
+  if (Opcode == XCore::STWSP_ru6 || Opcode == XCore::STWSP_lru6) 
+  {
+    if ((MI->getOperand(1).isFI()) && // is a stack slot
+        (MI->getOperand(2).isImm()) &&  // the imm is zero
+        (isZeroImm(MI->getOperand(2)))) 
+    {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+  else if (Opcode == XCore::STWSP_ru6_2 || Opcode == XCore::STWSP_lru6_2)
+  {
+    if (MI->getOperand(1).isFI())
+    {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+  return 0;
+}
+
+/// isInvariantLoad - Return true if the specified instruction (which is marked
+/// mayLoad) is loading from a location whose value is invariant across the
+/// function.  For example, loading a value from the constant pool or from
+/// from the argument area of a function if it does not change.  This should
+/// only return true of *all* loads the instruction does are invariant (if it
+/// does multiple loads).
+bool
+XCoreInstrInfo::isInvariantLoad(MachineInstr *MI) const {
+  // Loads from constants pools and loads from invariant argument slots are
+  // invariant
+  int Opcode = MI->getOpcode();
+  if (Opcode == XCore::LDWCP_ru6 || Opcode == XCore::LDWCP_lru6) {
+    return MI->getOperand(1).isCPI();
+  }
+  int FrameIndex;
+  if (isLoadFromStackSlot(MI, FrameIndex)) {
+    const MachineFrameInfo &MFI =
+      *MI->getParent()->getParent()->getFrameInfo();
+    return MFI.isFixedObjectIndex(FrameIndex) &&
+           MFI.isImmutableObjectIndex(FrameIndex);
+  }
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// Branch Analysis
+//===----------------------------------------------------------------------===//
+
+static inline bool IsBRU(unsigned BrOpc) {
+  return BrOpc == XCore::BRFU_u6
+      || BrOpc == XCore::BRFU_lu6
+      || BrOpc == XCore::BRBU_u6
+      || BrOpc == XCore::BRBU_lu6;
+}
+
+static inline bool IsBRT(unsigned BrOpc) {
+  return BrOpc == XCore::BRFT_ru6
+      || BrOpc == XCore::BRFT_lru6
+      || BrOpc == XCore::BRBT_ru6
+      || BrOpc == XCore::BRBT_lru6;
+}
+
+static inline bool IsBRF(unsigned BrOpc) {
+  return BrOpc == XCore::BRFF_ru6
+      || BrOpc == XCore::BRFF_lru6
+      || BrOpc == XCore::BRBF_ru6
+      || BrOpc == XCore::BRBF_lru6;
+}
+
+static inline bool IsCondBranch(unsigned BrOpc) {
+  return IsBRF(BrOpc) || IsBRT(BrOpc);
+}
+
+/// GetCondFromBranchOpc - Return the XCore CC that matches 
+/// the correspondent Branch instruction opcode.
+static XCore::CondCode GetCondFromBranchOpc(unsigned BrOpc) 
+{
+  if (IsBRT(BrOpc)) {
+    return XCore::COND_TRUE;
+  } else if (IsBRF(BrOpc)) {
+    return XCore::COND_FALSE;
+  } else {
+    return XCore::COND_INVALID;
+  }
+}
+
+/// GetCondBranchFromCond - Return the Branch instruction
+/// opcode that matches the cc.
+static inline unsigned GetCondBranchFromCond(XCore::CondCode CC) 
+{
+  switch (CC) {
+  default: assert(0 && "Illegal condition code!");
+  case XCore::COND_TRUE   : return XCore::BRFT_lru6;
+  case XCore::COND_FALSE  : return XCore::BRFF_lru6;
+  }
+}
+
+/// GetOppositeBranchCondition - Return the inverse of the specified 
+/// condition, e.g. turning COND_E to COND_NE.
+static inline XCore::CondCode GetOppositeBranchCondition(XCore::CondCode CC)
+{
+  switch (CC) {
+  default: assert(0 && "Illegal condition code!");
+  case XCore::COND_TRUE   : return XCore::COND_FALSE;
+  case XCore::COND_FALSE  : return XCore::COND_TRUE;
+  }
+}
+
+/// AnalyzeBranch - Analyze the branching code at the end of MBB, returning
+/// true if it cannot be understood (e.g. it's a switch dispatch or isn't
+/// implemented for a target).  Upon success, this returns false and returns
+/// with the following information in various cases:
+///
+/// 1. If this block ends with no branches (it just falls through to its succ)
+///    just return false, leaving TBB/FBB null.
+/// 2. If this block ends with only an unconditional branch, it sets TBB to be
+///    the destination block.
+/// 3. If this block ends with an conditional branch and it falls through to
+///    an successor block, it sets TBB to be the branch destination block and a
+///    list of operands that evaluate the condition. These
+///    operands can be passed to other TargetInstrInfo methods to create new
+///    branches.
+/// 4. If this block ends with an conditional branch and an unconditional
+///    block, it returns the 'true' destination in TBB, the 'false' destination
+///    in FBB, and a list of operands that evaluate the condition. These
+///    operands can be passed to other TargetInstrInfo methods to create new
+///    branches.
+///
+/// Note that RemoveBranch and InsertBranch must be implemented to support
+/// cases where this method returns success.
+///
+bool
+XCoreInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
+                           MachineBasicBlock *&FBB,
+                           SmallVectorImpl<MachineOperand> &Cond) const {
+  // If the block has no terminators, it just falls into the block after it.
+  MachineBasicBlock::iterator I = MBB.end();
+  if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
+    return false;
+
+  // Get the last instruction in the block.
+  MachineInstr *LastInst = I;
+  
+  // If there is only one terminator instruction, process it.
+  if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
+    if (IsBRU(LastInst->getOpcode())) {
+      TBB = LastInst->getOperand(0).getMBB();
+      return false;
+    }
+    
+    XCore::CondCode BranchCode = GetCondFromBranchOpc(LastInst->getOpcode());
+    if (BranchCode == XCore::COND_INVALID)
+      return true;  // Can't handle indirect branch.
+    
+    // Conditional branch
+    // Block ends with fall-through condbranch.
+
+    TBB = LastInst->getOperand(1).getMBB();
+    Cond.push_back(MachineOperand::CreateImm(BranchCode));
+    Cond.push_back(LastInst->getOperand(0));
+    return false;
+  }
+  
+  // Get the instruction before it if it's a terminator.
+  MachineInstr *SecondLastInst = I;
+
+  // If there are three terminators, we don't know what sort of block this is.
+  if (SecondLastInst && I != MBB.begin() &&
+      isUnpredicatedTerminator(--I))
+    return true;
+  
+  unsigned SecondLastOpc    = SecondLastInst->getOpcode();
+  XCore::CondCode BranchCode = GetCondFromBranchOpc(SecondLastOpc);
+  
+  // If the block ends with conditional branch followed by unconditional,
+  // handle it.
+  if (BranchCode != XCore::COND_INVALID
+    && IsBRU(LastInst->getOpcode())) {
+
+    TBB = SecondLastInst->getOperand(1).getMBB();
+    Cond.push_back(MachineOperand::CreateImm(BranchCode));
+    Cond.push_back(SecondLastInst->getOperand(0));
+
+    FBB = LastInst->getOperand(0).getMBB();
+    return false;
+  }
+  
+  // If the block ends with two unconditional branches, handle it.  The second
+  // one is not executed, so remove it.
+  if (IsBRU(SecondLastInst->getOpcode()) && 
+      IsBRU(LastInst->getOpcode())) {
+    TBB = SecondLastInst->getOperand(0).getMBB();
+    I = LastInst;
+    I->eraseFromParent();
+    return false;
+  }
+
+  // Otherwise, can't handle this.
+  return true;
+}
+
+unsigned
+XCoreInstrInfo::InsertBranch(MachineBasicBlock &MBB,MachineBasicBlock *TBB,
+                             MachineBasicBlock *FBB,
+                             const SmallVectorImpl<MachineOperand> &Cond)const{
+  // Shouldn't be a fall through.
+  assert(TBB && "InsertBranch must not be told to insert a fallthrough");
+  assert((Cond.size() == 2 || Cond.size() == 0) &&
+         "Unexpected number of components!");
+  
+  if (FBB == 0) { // One way branch.
+    if (Cond.empty()) {
+      // Unconditional branch
+      BuildMI(&MBB, get(XCore::BRFU_lu6)).addMBB(TBB);
+    } else {
+      // Conditional branch.
+      unsigned Opc = GetCondBranchFromCond((XCore::CondCode)Cond[0].getImm());
+      BuildMI(&MBB, get(Opc)).addReg(Cond[1].getReg())
+                             .addMBB(TBB);
+    }
+    return 1;
+  }
+  
+  // Two-way Conditional branch.
+  assert(Cond.size() == 2 && "Unexpected number of components!");
+  unsigned Opc = GetCondBranchFromCond((XCore::CondCode)Cond[0].getImm());
+  BuildMI(&MBB, get(Opc)).addReg(Cond[1].getReg())
+                         .addMBB(TBB);
+  BuildMI(&MBB, get(XCore::BRFU_lu6)).addMBB(FBB);
+  return 2;
+}
+
+unsigned
+XCoreInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+  MachineBasicBlock::iterator I = MBB.end();
+  if (I == MBB.begin()) return 0;
+  --I;
+  if (!IsBRU(I->getOpcode()) && !IsCondBranch(I->getOpcode()))
+    return 0;
+  
+  // Remove the branch.
+  I->eraseFromParent();
+  
+  I = MBB.end();
+
+  if (I == MBB.begin()) return 1;
+  --I;
+  if (!IsCondBranch(I->getOpcode()))
+    return 1;
+  
+  // Remove the branch.
+  I->eraseFromParent();
+  return 2;
+}
+
+bool XCoreInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
+                                     MachineBasicBlock::iterator I,
+                                     unsigned DestReg, unsigned SrcReg,
+                                     const TargetRegisterClass *DestRC,
+                                     const TargetRegisterClass *SrcRC) const {
+  if (DestRC == SrcRC) {
+    if (DestRC == XCore::GRRegsRegisterClass) {
+      BuildMI(MBB, I, get(XCore::ADD_2rus), DestReg).addReg(SrcReg).addImm(0);
+      return true;
+    } else {
+      return false;
+    }
+  }
+  
+  if (SrcRC == XCore::RRegsRegisterClass && SrcReg == XCore::SP &&
+    DestRC == XCore::GRRegsRegisterClass) {
+    BuildMI(MBB, I, get(XCore::LDAWSP_ru6), DestReg).addImm(0).addImm(0);
+    return true;
+  }
+  if (DestRC == XCore::RRegsRegisterClass && DestReg == XCore::SP &&
+    SrcRC == XCore::GRRegsRegisterClass) {
+    BuildMI(MBB, I, get(XCore::SETSP_1r)).addReg(SrcReg);
+    return true;
+  }
+  return false;
+}
+
+void XCoreInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
+                                  MachineBasicBlock::iterator I,
+                                  unsigned SrcReg, bool isKill, int FrameIndex,
+                                  const TargetRegisterClass *RC) const
+{
+  BuildMI(MBB, I, get(XCore::STWSP_lru6)).addReg(SrcReg, false, false, isKill)
+                                         .addFrameIndex(FrameIndex).addImm(0);
+}
+
+void XCoreInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                            bool isKill, SmallVectorImpl<MachineOperand> &Addr,
+                            const TargetRegisterClass *RC,
+                            SmallVectorImpl<MachineInstr*> &NewMIs) const
+{
+  assert(0 && "unimplemented\n");
+}
+
+void XCoreInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
+                                  MachineBasicBlock::iterator I,
+                                  unsigned DestReg, int FrameIndex,
+                                  const TargetRegisterClass *RC) const
+{
+  BuildMI(MBB, I, get(XCore::LDWSP_lru6), DestReg).addFrameIndex(FrameIndex)
+                                                  .addImm(0);
+}
+
+void XCoreInstrInfo::loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
+                              SmallVectorImpl<MachineOperand> &Addr,
+                              const TargetRegisterClass *RC,
+                              SmallVectorImpl<MachineInstr*> &NewMIs) const
+{
+  assert(0 && "unimplemented\n");
+}
+
+bool XCoreInstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+				MachineBasicBlock::iterator MI,
+			const std::vector<CalleeSavedInfo> &CSI) const
+{
+  if (CSI.empty()) {
+    return true;
+  }
+  MachineFunction *MF = MBB.getParent();
+  const MachineFrameInfo *MFI = MF->getFrameInfo();
+  MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
+  XCoreFunctionInfo *XFI = MF->getInfo<XCoreFunctionInfo>();
+  
+  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(*MF);
+  
+  for (std::vector<CalleeSavedInfo>::const_iterator it = CSI.begin();
+                                                    it != CSI.end(); ++it) {
+    // Add the callee-saved register as live-in. It's killed at the spill.
+    MBB.addLiveIn(it->getReg());
+
+    storeRegToStackSlot(MBB, MI, it->getReg(), true,
+                                   it->getFrameIdx(), it->getRegClass());
+    if (emitFrameMoves) {
+      unsigned SaveLabelId = MMI->NextLabelID();
+      BuildMI(MBB, MI, get(XCore::DBG_LABEL)).addImm(SaveLabelId);
+      XFI->getSpillLabels().push_back(
+          std::pair<unsigned, CalleeSavedInfo>(SaveLabelId, *it));
+    }
+  }
+  return true;
+}
+
+bool XCoreInstrInfo::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                         MachineBasicBlock::iterator MI,
+                               const std::vector<CalleeSavedInfo> &CSI) const
+{
+  bool AtStart = MI == MBB.begin();
+  MachineBasicBlock::iterator BeforeI = MI;
+  if (!AtStart)
+    --BeforeI;
+  for (std::vector<CalleeSavedInfo>::const_iterator it = CSI.begin();
+                                                    it != CSI.end(); ++it) {
+    
+    loadRegFromStackSlot(MBB, MI, it->getReg(),
+                                  it->getFrameIdx(),
+                                  it->getRegClass());
+    assert(MI != MBB.begin() &&
+           "loadRegFromStackSlot didn't insert any code!");
+    // Insert in reverse order.  loadRegFromStackSlot can insert multiple
+    // instructions.
+    if (AtStart)
+      MI = MBB.begin();
+    else {
+      MI = BeforeI;
+      ++MI;
+    }
+  }
+  return true;
+}
+
+/// BlockHasNoFallThrough - Analyse if MachineBasicBlock does not
+/// fall-through into its successor block.
+bool XCoreInstrInfo::
+BlockHasNoFallThrough(const MachineBasicBlock &MBB) const 
+{
+  if (MBB.empty()) return false;
+  
+  switch (MBB.back().getOpcode()) {
+  case XCore::RETSP_u6:     // Return.
+  case XCore::RETSP_lu6:
+  case XCore::BAU_1r:       // Indirect branch.
+  case XCore::BRFU_u6:      // Uncond branch.
+  case XCore::BRFU_lu6:
+  case XCore::BRBU_u6:
+  case XCore::BRBU_lu6:
+    return true;
+  default: return false;
+  }
+}
+
+/// ReverseBranchCondition - Return the inverse opcode of the 
+/// specified Branch instruction.
+bool XCoreInstrInfo::
+ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const 
+{
+  assert((Cond.size() == 2) && 
+          "Invalid XCore branch condition!");
+  Cond[0].setImm(GetOppositeBranchCondition((XCore::CondCode)Cond[0].getImm()));
+  return false;
+}