[llvm] r194026 - Revert r194019 to r194021, "Submit the basic port of the rest of ARM constant islands code to Mips."

reed kotler rkotler at mips.com
Mon Nov 4 15:54:41 PST 2013


Which bot is broken?
r194021 fixed the build i thought.

On 11/04/2013 03:14 PM, NAKAMURA Takumi wrote:
> Author: chapuni
> Date: Mon Nov  4 17:14:36 2013
> New Revision: 194026
>
> URL: http://llvm.org/viewvc/llvm-project?rev=194026&view=rev
> Log:
> Revert r194019 to r194021, "Submit the basic port of the rest of ARM constant islands code to Mips."
>
> It broke -Asserts build.
>
> Removed:
>      llvm/trunk/test/CodeGen/Mips/const4.ll
> Modified:
>      llvm/trunk/lib/Target/Mips/Mips16InstrInfo.td
>      llvm/trunk/lib/Target/Mips/MipsConstantIslandPass.cpp
>
> Modified: llvm/trunk/lib/Target/Mips/Mips16InstrInfo.td
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/Mips16InstrInfo.td?rev=194026&r1=194025&r2=194026&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/Mips/Mips16InstrInfo.td (original)
> +++ llvm/trunk/lib/Target/Mips/Mips16InstrInfo.td Mon Nov  4 17:14:36 2013
> @@ -60,11 +60,6 @@ class FRI16_ins<bits<5> op, string asmst
>                   InstrItinClass itin>:
>     FRI16_ins_base<op, asmstr, "\t$rx, $imm \t# 16 bit inst", itin>;
>
> -class FRI16_TCP_ins<bits<5> _op, string asmstr,
> -                    InstrItinClass itin>:
> -  FRI16<_op, (outs CPU16Regs:$rx), (ins pcrel16:$imm, i32imm:$size),
> -            !strconcat(asmstr, "\t$rx, $imm\t# 16 bit inst"), [], itin>;
> -
>   class FRI16R_ins_base<bits<5> op, string asmstr, string asmstr2,
>                        InstrItinClass itin>:
>     FRI16<op, (outs), (ins CPU16Regs:$rx, simm16:$imm),
> @@ -179,7 +174,7 @@ class FEXT_RI16_B_ins<bits<5> _op, strin
>
>   class FEXT_RI16_TCP_ins<bits<5> _op, string asmstr,
>                           InstrItinClass itin>:
> -  FEXT_RI16<_op, (outs CPU16Regs:$rx), (ins pcrel16:$imm, i32imm:$size),
> +  FEXT_RI16<_op, (outs CPU16Regs:$rx), (ins pcrel16:$imm),
>               !strconcat(asmstr, "\t$rx, $imm"), [], itin>;
>
>   class FEXT_2RI16_ins<bits<5> _op, string asmstr,
> @@ -807,8 +802,6 @@ def LwRxSpImmX16: FEXT_RI16_SP_explicit_
>     let Uses = [SP];
>   }
>
> -def LwRxPcTcp16: FRI16_TCP_ins<0b10110, "lw", IILoad>, MayLoad;
> -
>   def LwRxPcTcpX16: FEXT_RI16_TCP_ins<0b10110, "lw", IILoad>, MayLoad;
>   //
>   // Format: MOVE r32, rz MIPS16e
> @@ -1876,4 +1869,3 @@ let neverHasSideEffects = 1, isNotDuplic
>   def CONSTPOOL_ENTRY :
>   MipsPseudo16<(outs), (ins cpinst_operand:$instid, cpinst_operand:$cpidx,
>                         i32imm:$size), "foo", []>;
> -
>
> Modified: llvm/trunk/lib/Target/Mips/MipsConstantIslandPass.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsConstantIslandPass.cpp?rev=194026&r1=194025&r2=194026&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/Mips/MipsConstantIslandPass.cpp (original)
> +++ llvm/trunk/lib/Target/Mips/MipsConstantIslandPass.cpp Mon Nov  4 17:14:36 2013
> @@ -27,7 +27,6 @@
>
>   #include "Mips.h"
>   #include "MCTargetDesc/MipsBaseInfo.h"
> -#include "MipsMachineFunction.h"
>   #include "MipsTargetMachine.h"
>   #include "llvm/ADT/Statistic.h"
>   #include "llvm/CodeGen/MachineBasicBlock.h"
> @@ -43,197 +42,30 @@
>   #include "llvm/Target/TargetInstrInfo.h"
>   #include "llvm/Target/TargetMachine.h"
>   #include "llvm/Target/TargetRegisterInfo.h"
> -#include "llvm/Support/Format.h"
>   #include <algorithm>
>
>   using namespace llvm;
>
>   STATISTIC(NumCPEs,       "Number of constpool entries");
> -STATISTIC(NumSplit,      "Number of uncond branches inserted");
> -#ifdef IN_PROGRESS
> -STATISTIC(NumCBrFixed,   "Number of cond branches fixed");
> -#endif
> -STATISTIC(NumUBrFixed,   "Number of uncond branches fixed");
>
>   // FIXME: This option should be removed once it has received sufficient testing.
>   static cl::opt<bool>
>   AlignConstantIslands("mips-align-constant-islands", cl::Hidden, cl::init(true),
>             cl::desc("Align constant islands in code"));
>
> -
> -// Rather than do make check tests with huge amounts of code, we force
> -// the test to use this amount.
> -//
> -static cl::opt<int> ConstantIslandsSmallOffset(
> -  "mips-constant-islands-small-offset",
> -  cl::init(0),
> -  cl::desc("Make small offsets be this amount for testing purposes"),
> -  cl::Hidden);
> -
> -/// UnknownPadding - Return the worst case padding that could result from
> -/// unknown offset bits.  This does not include alignment padding caused by
> -/// known offset bits.
> -///
> -/// @param LogAlign log2(alignment)
> -/// @param KnownBits Number of known low offset bits.
> -static inline unsigned UnknownPadding(unsigned LogAlign, unsigned KnownBits) {
> -  if (KnownBits < LogAlign)
> -    return (1u << LogAlign) - (1u << KnownBits);
> -  return 0;
> -}
> -
>   namespace {
> -
> -
>     typedef MachineBasicBlock::iterator Iter;
>     typedef MachineBasicBlock::reverse_iterator ReverseIter;
>
> -  /// MipsConstantIslands - Due to limited PC-relative displacements, Mips
> -  /// requires constant pool entries to be scattered among the instructions
> -  /// inside a function.  To do this, it completely ignores the normal LLVM
> -  /// constant pool; instead, it places constants wherever it feels like with
> -  /// special instructions.
> -  ///
> -  /// The terminology used in this pass includes:
> -  ///   Islands - Clumps of constants placed in the function.
> -  ///   Water   - Potential places where an island could be formed.
> -  ///   CPE     - A constant pool entry that has been placed somewhere, which
> -  ///             tracks a list of users.
> -
>     class MipsConstantIslands : public MachineFunctionPass {
>
> -    /// BasicBlockInfo - Information about the offset and size of a single
> -    /// basic block.
> -    struct BasicBlockInfo {
> -      /// Offset - Distance from the beginning of the function to the beginning
> -      /// of this basic block.
> -      ///
> -      /// Offsets are computed assuming worst case padding before an aligned
> -      /// block. This means that subtracting basic block offsets always gives a
> -      /// conservative estimate of the real distance which may be smaller.
> -      ///
> -      /// Because worst case padding is used, the computed offset of an aligned
> -      /// block may not actually be aligned.
> -      unsigned Offset;
> -
> -      /// Size - Size of the basic block in bytes.  If the block contains
> -      /// inline assembly, this is a worst case estimate.
> -      ///
> -      /// The size does not include any alignment padding whether from the
> -      /// beginning of the block, or from an aligned jump table at the end.
> -      unsigned Size;
> -
> -      /// KnownBits - The number of low bits in Offset that are known to be
> -      /// exact.  The remaining bits of Offset are an upper bound.
> -      uint8_t KnownBits;
> -
> -      /// Unalign - When non-zero, the block contains instructions (inline asm)
> -      /// of unknown size.  The real size may be smaller than Size bytes by a
> -      /// multiple of 1 << Unalign.
> -      uint8_t Unalign;
> -
> -      /// PostAlign - When non-zero, the block terminator contains a .align
> -      /// directive, so the end of the block is aligned to 1 << PostAlign
> -      /// bytes.
> -      uint8_t PostAlign;
> -
> -      BasicBlockInfo() : Offset(0), Size(0), KnownBits(0), Unalign(0),
> -        PostAlign(0) {}
> -
> -      /// Compute the number of known offset bits internally to this block.
> -      /// This number should be used to predict worst case padding when
> -      /// splitting the block.
> -      unsigned internalKnownBits() const {
> -        unsigned Bits = Unalign ? Unalign : KnownBits;
> -        // If the block size isn't a multiple of the known bits, assume the
> -        // worst case padding.
> -        if (Size & ((1u << Bits) - 1))
> -          Bits = countTrailingZeros(Size);
> -        return Bits;
> -      }
> -
> -      /// Compute the offset immediately following this block.  If LogAlign is
> -      /// specified, return the offset the successor block will get if it has
> -      /// this alignment.
> -      unsigned postOffset(unsigned LogAlign = 0) const {
> -        unsigned PO = Offset + Size;
> -        return PO;
> -      }
> -
> -      /// Compute the number of known low bits of postOffset.  If this block
> -      /// contains inline asm, the number of known bits drops to the
> -      /// instruction alignment.  An aligned terminator may increase the number
> -      /// of know bits.
> -      /// If LogAlign is given, also consider the alignment of the next block.
> -      unsigned postKnownBits(unsigned LogAlign = 0) const {
> -        return std::max(std::max(unsigned(PostAlign), LogAlign),
> -                        internalKnownBits());
> -      }
> -    };
> -
> -    std::vector<BasicBlockInfo> BBInfo;
> -
> -    /// WaterList - A sorted list of basic blocks where islands could be placed
> -    /// (i.e. blocks that don't fall through to the following block, due
> -    /// to a return, unreachable, or unconditional branch).
> -    std::vector<MachineBasicBlock*> WaterList;
> -
> -    /// NewWaterList - The subset of WaterList that was created since the
> -    /// previous iteration by inserting unconditional branches.
> -    SmallSet<MachineBasicBlock*, 4> NewWaterList;
> -
> -    typedef std::vector<MachineBasicBlock*>::iterator water_iterator;
> -
> -    /// CPUser - One user of a constant pool, keeping the machine instruction
> -    /// pointer, the constant pool being referenced, and the max displacement
> -    /// allowed from the instruction to the CP.  The HighWaterMark records the
> -    /// highest basic block where a new CPEntry can be placed.  To ensure this
> -    /// pass terminates, the CP entries are initially placed at the end of the
> -    /// function and then move monotonically to lower addresses.  The
> -    /// exception to this rule is when the current CP entry for a particular
> -    /// CPUser is out of range, but there is another CP entry for the same
> -    /// constant value in range.  We want to use the existing in-range CP
> -    /// entry, but if it later moves out of range, the search for new water
> -    /// should resume where it left off.  The HighWaterMark is used to record
> -    /// that point.
> -    struct CPUser {
> -      MachineInstr *MI;
> -      MachineInstr *CPEMI;
> -      MachineBasicBlock *HighWaterMark;
> -    private:
> -      unsigned MaxDisp;
> -      unsigned LongFormMaxDisp; // mips16 has 16/32 bit instructions
> -                                // with different displacements
> -      unsigned LongFormOpcode;
> -    public:
> -      bool NegOk;
> -      bool IsSoImm;
> -      bool KnownAlignment;
> -      CPUser(MachineInstr *mi, MachineInstr *cpemi, unsigned maxdisp,
> -             bool neg, bool soimm, unsigned longformmaxdisp, unsigned longformopcode)
> -        : MI(mi), CPEMI(cpemi), MaxDisp(maxdisp),
> -          LongFormMaxDisp(longformmaxdisp), LongFormOpcode(longformopcode),
> -          NegOk(neg), IsSoImm(soimm), KnownAlignment(false)  {
> -        HighWaterMark = CPEMI->getParent();
> -      }
> -      /// getMaxDisp - Returns the maximum displacement supported by MI.
> -      /// Correct for unknown alignment.
> -      /// Conservatively subtract 2 bytes to handle weird alignment effects.
> -      unsigned getMaxDisp() const {
> -        unsigned xMaxDisp = ConstantIslandsSmallOffset? ConstantIslandsSmallOffset: MaxDisp;
> -        return (KnownAlignment ? xMaxDisp : xMaxDisp - 2) - 2;
> -      }
> -      unsigned getLongFormMaxDisp() const {
> -        return (KnownAlignment ? LongFormMaxDisp : LongFormMaxDisp - 2) - 2;
> -      }
> -      unsigned getLongFormOpcode() const {
> -          return LongFormOpcode;
> -      }
> -    };
> -
> -    /// CPUsers - Keep track of all of the machine instructions that use various
> -    /// constant pools and their max displacement.
> -    std::vector<CPUser> CPUsers;
> +  const TargetMachine &TM;
> +  bool IsPIC;
> +  unsigned ABI;
> +  const MipsSubtarget *STI;
> +  const MipsInstrInfo *TII;
> +  MachineFunction *MF;
> +  MachineConstantPool *MCP;
>
>     /// CPEntry - One per constant pool entry, keeping the machine instruction
>     /// pointer, the constpool index, and the number of CPUser's which
> @@ -253,55 +85,13 @@ namespace {
>     /// put in the vector of the original element, but have distinct CPIs.
>     std::vector<std::vector<CPEntry> > CPEntries;
>
> -  /// ImmBranch - One per immediate branch, keeping the machine instruction
> -  /// pointer, conditional or unconditional, the max displacement,
> -  /// and (if isCond is true) the corresponding unconditional branch
> -  /// opcode.
> -  struct ImmBranch {
> -    MachineInstr *MI;
> -    unsigned MaxDisp : 31;
> -    bool isCond : 1;
> -    int UncondBr;
> -    ImmBranch(MachineInstr *mi, unsigned maxdisp, bool cond, int ubr)
> -      : MI(mi), MaxDisp(maxdisp), isCond(cond), UncondBr(ubr) {}
> -  };
> -
> -  /// ImmBranches - Keep track of all the immediate branch instructions.
> -  ///
> -  std::vector<ImmBranch> ImmBranches;
> -
> -  /// HasFarJump - True if any far jump instruction has been emitted during
> -  /// the branch fix up pass.
> -  bool HasFarJump;
> -
> -  const TargetMachine &TM;
> -  bool IsPIC;
> -  unsigned ABI;
> -  const MipsSubtarget *STI;
> -  const MipsInstrInfo *TII;
> -  MipsFunctionInfo *MFI;
> -  MachineFunction *MF;
> -  MachineConstantPool *MCP;
> -
> -  unsigned PICLabelUId;
> -  bool PrescannedForConstants;
> -
> -  void initPICLabelUId(unsigned UId) {
> -    PICLabelUId = UId;
> -  }
> -
> -
> -  unsigned createPICLabelUId() {
> -    return PICLabelUId++;
> -  }
> -
>     public:
>       static char ID;
>       MipsConstantIslands(TargetMachine &tm)
>         : MachineFunctionPass(ID), TM(tm),
>           IsPIC(TM.getRelocationModel() == Reloc::PIC_),
>           ABI(TM.getSubtarget<MipsSubtarget>().getTargetABI()),
> -        STI(&TM.getSubtarget<MipsSubtarget>()), MF(0), MCP(0), PrescannedForConstants(false){}
> +        STI(&TM.getSubtarget<MipsSubtarget>()), MF(0), MCP(0){}
>
>       virtual const char *getPassName() const {
>         return "Mips Constant Islands";
> @@ -310,49 +100,6 @@ namespace {
>       bool runOnMachineFunction(MachineFunction &F);
>
>       void doInitialPlacement(std::vector<MachineInstr*> &CPEMIs);
> -    CPEntry *findConstPoolEntry(unsigned CPI, const MachineInstr *CPEMI);
> -    unsigned getCPELogAlign(const MachineInstr *CPEMI);
> -    void initializeFunctionInfo(const std::vector<MachineInstr*> &CPEMIs);
> -    unsigned getOffsetOf(MachineInstr *MI) const;
> -    unsigned getUserOffset(CPUser&) const;
> -    void dumpBBs();
> -    void verify();
> -
> -    bool isOffsetInRange(unsigned UserOffset, unsigned TrialOffset,
> -                         unsigned Disp, bool NegativeOK, bool IsSoImm = false);
> -    bool isOffsetInRange(unsigned UserOffset, unsigned TrialOffset,
> -                         const CPUser &U) {
> -      return isOffsetInRange(UserOffset, TrialOffset,
> -                             U.getMaxDisp(), U.NegOk, U.IsSoImm);
> -    }
> -    bool isLongFormOffsetInRange(unsigned UserOffset, unsigned TrialOffset,
> -                                const CPUser &U) {
> -      return isOffsetInRange(UserOffset, TrialOffset,
> -                             U.getLongFormMaxDisp(), U.NegOk, U.IsSoImm);
> -    }
> -    void computeBlockSize(MachineBasicBlock *MBB);
> -    MachineBasicBlock *splitBlockBeforeInstr(MachineInstr *MI);
> -    void updateForInsertedWaterBlock(MachineBasicBlock *NewBB);
> -    void adjustBBOffsetsAfter(MachineBasicBlock *BB);
> -    bool decrementCPEReferenceCount(unsigned CPI, MachineInstr* CPEMI);
> -    int findInRangeCPEntry(CPUser& U, unsigned UserOffset);
> -    int findLongFormInRangeCPEntry(CPUser& U, unsigned UserOffset);
> -    bool findAvailableWater(CPUser&U, unsigned UserOffset,
> -                            water_iterator &WaterIter);
> -    void createNewWater(unsigned CPUserIndex, unsigned UserOffset,
> -                        MachineBasicBlock *&NewMBB);
> -    bool handleConstantPoolUser(unsigned CPUserIndex);
> -    void removeDeadCPEMI(MachineInstr *CPEMI);
> -    bool removeUnusedCPEntries();
> -    bool isCPEntryInRange(MachineInstr *MI, unsigned UserOffset,
> -                          MachineInstr *CPEMI, unsigned Disp, bool NegOk,
> -                          bool DoDump = false);
> -    bool isWaterInRange(unsigned UserOffset, MachineBasicBlock *Water,
> -                        CPUser &U, unsigned &Growth);
> -    bool isBBInRange(MachineInstr *MI, MachineBasicBlock *BB, unsigned Disp);
> -    bool fixupImmediateBr(ImmBranch &Br);
> -    bool fixupConditionalBr(ImmBranch &Br);
> -    bool fixupUnconditionalBr(ImmBranch &Br);
>
>       void prescanForConstants();
>
> @@ -363,19 +110,6 @@ namespace {
>     char MipsConstantIslands::ID = 0;
>   } // end of anonymous namespace
>
> -/// print block size and offset information - debugging
> -void MipsConstantIslands::dumpBBs() {
> -  DEBUG({
> -    for (unsigned J = 0, E = BBInfo.size(); J !=E; ++J) {
> -      const BasicBlockInfo &BBI = BBInfo[J];
> -      dbgs() << format("%08x BB#%u\t", BBI.Offset, J)
> -             << " kb=" << unsigned(BBI.KnownBits)
> -             << " ua=" << unsigned(BBI.Unalign)
> -             << " pa=" << unsigned(BBI.PostAlign)
> -             << format(" size=%#x\n", BBInfo[J].Size);
> -    }
> -  });
> -}
>   /// createMipsLongBranchPass - Returns a pass that converts branches to long
>   /// branches.
>   FunctionPass *llvm::createMipsConstantIslandPass(MipsTargetMachine &tm) {
> @@ -393,15 +127,13 @@ bool MipsConstantIslands::runOnMachineFu
>       return false;
>     }
>     TII = (const MipsInstrInfo*)MF->getTarget().getInstrInfo();
> -  MFI = MF->getInfo<MipsFunctionInfo>();
>     DEBUG(dbgs() << "constant island processing " << "\n");
>     //
>     // will need to make predermination if there is any constants we need to
>     // put in constant islands. TBD.
>     //
> -  if (!PrescannedForConstants) prescanForConstants();
> +  prescanForConstants();
>
> -  HasFarJump = false;
>     // This pass invalidates liveness information when it splits basic blocks.
>     MF->getRegInfo().invalidateLiveness();
>
> @@ -409,66 +141,13 @@ bool MipsConstantIslands::runOnMachineFu
>     // the numbers agree with the position of the block in the function.
>     MF->RenumberBlocks();
>
> -  bool MadeChange = false;
> -
>     // Perform the initial placement of the constant pool entries.  To start with,
>     // we put them all at the end of the function.
>     std::vector<MachineInstr*> CPEMIs;
>     if (!MCP->isEmpty())
>       doInitialPlacement(CPEMIs);
>
> -  /// The next UID to take is the first unused one.
> -  initPICLabelUId(CPEMIs.size());
> -
> -  // Do the initial scan of the function, building up information about the
> -  // sizes of each block, the location of all the water, and finding all of the
> -  // constant pool users.
> -  initializeFunctionInfo(CPEMIs);
> -  CPEMIs.clear();
> -  DEBUG(dumpBBs());
> -
> -  /// Remove dead constant pool entries.
> -  MadeChange |= removeUnusedCPEntries();
> -
> -  // Iteratively place constant pool entries and fix up branches until there
> -  // is no change.
> -  unsigned NoCPIters = 0, NoBRIters = 0;
> -  (void)NoBRIters;
> -  while (true) {
> -    DEBUG(dbgs() << "Beginning CP iteration #" << NoCPIters << '\n');
> -    bool CPChange = false;
> -    for (unsigned i = 0, e = CPUsers.size(); i != e; ++i)
> -      CPChange |= handleConstantPoolUser(i);
> -    if (CPChange && ++NoCPIters > 30)
> -      report_fatal_error("Constant Island pass failed to converge!");
> -    DEBUG(dumpBBs());
> -
> -    // Clear NewWaterList now.  If we split a block for branches, it should
> -    // appear as "new water" for the next iteration of constant pool placement.
> -    NewWaterList.clear();
> -
> -    DEBUG(dbgs() << "Beginning BR iteration #" << NoBRIters << '\n');
> -    bool BRChange = false;
> -#ifdef IN_PROGRESS
> -    for (unsigned i = 0, e = ImmBranches.size(); i != e; ++i)
> -      BRChange |= fixupImmediateBr(ImmBranches[i]);
> -    if (BRChange && ++NoBRIters > 30)
> -      report_fatal_error("Branch Fix Up pass failed to converge!");
> -    DEBUG(dumpBBs());
> -#endif
> -    if (!CPChange && !BRChange)
> -      break;
> -    MadeChange = true;
> -  }
> -
> -  DEBUG(dbgs() << '\n'; dumpBBs());
> -
> -  BBInfo.clear();
> -  WaterList.clear();
> -  CPUsers.clear();
> -  CPEntries.clear();
> -  ImmBranches.clear();
> -  return MadeChange;
> +  return true;
>   }
>
>   /// doInitialPlacement - Perform the initial placement of the constant pool
> @@ -537,1165 +216,9 @@ MipsConstantIslands::doInitialPlacement(
>     DEBUG(BB->dump());
>   }
>
> -/// BBHasFallthrough - Return true if the specified basic block can fallthrough
> -/// into the block immediately after it.
> -static bool BBHasFallthrough(MachineBasicBlock *MBB) {
> -  // Get the next machine basic block in the function.
> -  MachineFunction::iterator MBBI = MBB;
> -  // Can't fall off end of function.
> -  if (llvm::next(MBBI) == MBB->getParent()->end())
> -    return false;
> -
> -  MachineBasicBlock *NextBB = llvm::next(MBBI);
> -  for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(),
> -       E = MBB->succ_end(); I != E; ++I)
> -    if (*I == NextBB)
> -      return true;
> -
> -  return false;
> -}
> -
> -/// findConstPoolEntry - Given the constpool index and CONSTPOOL_ENTRY MI,
> -/// look up the corresponding CPEntry.
> -MipsConstantIslands::CPEntry
> -*MipsConstantIslands::findConstPoolEntry(unsigned CPI,
> -                                        const MachineInstr *CPEMI) {
> -  std::vector<CPEntry> &CPEs = CPEntries[CPI];
> -  // Number of entries per constpool index should be small, just do a
> -  // linear search.
> -  for (unsigned i = 0, e = CPEs.size(); i != e; ++i) {
> -    if (CPEs[i].CPEMI == CPEMI)
> -      return &CPEs[i];
> -  }
> -  return NULL;
> -}
> -
> -/// getCPELogAlign - Returns the required alignment of the constant pool entry
> -/// represented by CPEMI.  Alignment is measured in log2(bytes) units.
> -unsigned MipsConstantIslands::getCPELogAlign(const MachineInstr *CPEMI) {
> -  assert(CPEMI && CPEMI->getOpcode() == Mips::CONSTPOOL_ENTRY);
> -
> -  // Everything is 4-byte aligned unless AlignConstantIslands is set.
> -  if (!AlignConstantIslands)
> -    return 2;
> -
> -  unsigned CPI = CPEMI->getOperand(1).getIndex();
> -  assert(CPI < MCP->getConstants().size() && "Invalid constant pool index.");
> -  unsigned Align = MCP->getConstants()[CPI].getAlignment();
> -  assert(isPowerOf2_32(Align) && "Invalid CPE alignment");
> -  return Log2_32(Align);
> -}
> -
> -/// initializeFunctionInfo - Do the initial scan of the function, building up
> -/// information about the sizes of each block, the location of all the water,
> -/// and finding all of the constant pool users.
> -void MipsConstantIslands::
> -initializeFunctionInfo(const std::vector<MachineInstr*> &CPEMIs) {
> -  BBInfo.clear();
> -  BBInfo.resize(MF->getNumBlockIDs());
> -
> -  // First thing, compute the size of all basic blocks, and see if the function
> -  // has any inline assembly in it. If so, we have to be conservative about
> -  // alignment assumptions, as we don't know for sure the size of any
> -  // instructions in the inline assembly.
> -  for (MachineFunction::iterator I = MF->begin(), E = MF->end(); I != E; ++I)
> -    computeBlockSize(I);
> -
> -  // The known bits of the entry block offset are determined by the function
> -  // alignment.
> -  BBInfo.front().KnownBits = MF->getAlignment();
> -
> -  // Compute block offsets.
> -  adjustBBOffsetsAfter(MF->begin());
> -
> -  // Now go back through the instructions and build up our data structures.
> -  for (MachineFunction::iterator MBBI = MF->begin(), E = MF->end();
> -       MBBI != E; ++MBBI) {
> -    MachineBasicBlock &MBB = *MBBI;
> -
> -    // If this block doesn't fall through into the next MBB, then this is
> -    // 'water' that a constant pool island could be placed.
> -    if (!BBHasFallthrough(&MBB))
> -      WaterList.push_back(&MBB);
> -    for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
> -         I != E; ++I) {
> -      if (I->isDebugValue())
> -        continue;
> -
> -      int Opc = I->getOpcode();
> -      if (I->isBranch()) {
> -        bool isCond = false;
> -        unsigned Bits = 0;
> -        unsigned Scale = 1;
> -        int UOpc = Opc;
> -
> -        switch (Opc) {
> -        default:
> -          continue;  // Ignore other JT branches
> -#ifdef IN_PROGRESS
> -        case ARM::t2BR_JT:
> -          T2JumpTables.push_back(I);
> -          continue;   // Does not get an entry in ImmBranches
> -        case ARM::Bcc:
> -          isCond = true;
> -          UOpc = ARM::B;
> -          // Fallthrough
> -        case ARM::B:
> -          Bits = 24;
> -          Scale = 4;
> -          break;
> -        case ARM::tBcc:
> -          isCond = true;
> -          UOpc = ARM::tB;
> -          Bits = 8;
> -          Scale = 2;
> -          break;
> -        case ARM::tB:
> -          Bits = 11;
> -          Scale = 2;
> -          break;
> -        case ARM::t2Bcc:
> -          isCond = true;
> -          UOpc = ARM::t2B;
> -          Bits = 20;
> -          Scale = 2;
> -          break;
> -        case ARM::t2B:
> -          Bits = 24;
> -          Scale = 2;
> -          break;
> -#endif
> -        }
> -        // Record this immediate branch.
> -        unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale;
> -        ImmBranches.push_back(ImmBranch(I, MaxOffs, isCond, UOpc));
> -
> -      }
> -
> -
> -      if (Opc == Mips::CONSTPOOL_ENTRY)
> -        continue;
> -
> -
> -      // Scan the instructions for constant pool operands.
> -      for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
> -        if (I->getOperand(op).isCPI()) {
> -
> -          // We found one.  The addressing mode tells us the max displacement
> -          // from the PC that this instruction permits.
> -
> -          // Basic size info comes from the TSFlags field.
> -          unsigned Bits = 0;
> -          unsigned Scale = 1;
> -          bool NegOk = false;
> -          bool IsSoImm = false;
> -          unsigned LongFormBits = 0;
> -          unsigned LongFormScale = 0;
> -          unsigned LongFormOpcode = 0;
> -          switch (Opc) {
> -          default:
> -            llvm_unreachable("Unknown addressing mode for CP reference!");
> -          case Mips::LwRxPcTcp16:
> -            Bits = 8;
> -            Scale = 2;
> -            LongFormOpcode = Mips::LwRxPcTcpX16;
> -            break;
> -          case Mips::LwRxPcTcpX16:
> -            Bits = 16;
> -            Scale = 2;
> -            break;
> -#ifdef IN_PROGRESS
> -          // Taking the address of a CP entry.
> -          case ARM::LEApcrel:
> -            // This takes a SoImm, which is 8 bit immediate rotated. We'll
> -            // pretend the maximum offset is 255 * 4. Since each instruction
> -            // 4 byte wide, this is always correct. We'll check for other
> -            // displacements that fits in a SoImm as well.
> -            Bits = 8;
> -            Scale = 4;
> -            NegOk = true;
> -            IsSoImm = true;
> -            break;
> -          case ARM::t2LEApcrel:
> -            Bits = 12;
> -            NegOk = true;
> -            break;
> -          case ARM::tLEApcrel:
> -            Bits = 8;
> -            Scale = 4;
> -            break;
> -
> -          case ARM::LDRBi12:
> -          case ARM::LDRi12:
> -          case ARM::LDRcp:
> -          case ARM::t2LDRpci:
> -            Bits = 12;  // +-offset_12
> -            NegOk = true;
> -            break;
> -
> -          case ARM::tLDRpci:
> -            Bits = 8;
> -            Scale = 4;  // +(offset_8*4)
> -            break;
> -
> -          case ARM::VLDRD:
> -          case ARM::VLDRS:
> -            Bits = 8;
> -            Scale = 4;  // +-(offset_8*4)
> -            NegOk = true;
> -            break;
> -#endif
> -          }
> -          // Remember that this is a user of a CP entry.
> -          unsigned CPI = I->getOperand(op).getIndex();
> -          MachineInstr *CPEMI = CPEMIs[CPI];
> -          unsigned MaxOffs = ((1 << Bits)-1) * Scale;
> -          unsigned LongFormMaxOffs = ((1 << LongFormBits)-1) * LongFormScale;
> -          CPUsers.push_back(CPUser(I, CPEMI, MaxOffs, NegOk, IsSoImm, LongFormMaxOffs,
> -                                   LongFormOpcode));
> -
> -          // Increment corresponding CPEntry reference count.
> -          CPEntry *CPE = findConstPoolEntry(CPI, CPEMI);
> -          assert(CPE && "Cannot find a corresponding CPEntry!");
> -          CPE->RefCount++;
> -
> -          // Instructions can only use one CP entry, don't bother scanning the
> -          // rest of the operands.
> -          break;
> -
> -        }
> -
> -    }
> -  }
> -
> -}
> -
> -/// computeBlockSize - Compute the size and some alignment information for MBB.
> -/// This function updates BBInfo directly.
> -void MipsConstantIslands::computeBlockSize(MachineBasicBlock *MBB) {
> -  BasicBlockInfo &BBI = BBInfo[MBB->getNumber()];
> -  BBI.Size = 0;
> -  BBI.Unalign = 0;
> -  BBI.PostAlign = 0;
> -
> -  for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E;
> -       ++I)
> -    BBI.Size += TII->GetInstSizeInBytes(I);
> -
> -}
> -
> -/// getOffsetOf - Return the current offset of the specified machine instruction
> -/// from the start of the function.  This offset changes as stuff is moved
> -/// around inside the function.
> -unsigned MipsConstantIslands::getOffsetOf(MachineInstr *MI) const {
> -  MachineBasicBlock *MBB = MI->getParent();
> -
> -  // The offset is composed of two things: the sum of the sizes of all MBB's
> -  // before this instruction's block, and the offset from the start of the block
> -  // it is in.
> -  unsigned Offset = BBInfo[MBB->getNumber()].Offset;
> -
> -  // Sum instructions before MI in MBB.
> -  for (MachineBasicBlock::iterator I = MBB->begin(); &*I != MI; ++I) {
> -    assert(I != MBB->end() && "Didn't find MI in its own basic block?");
> -    Offset += TII->GetInstSizeInBytes(I);
> -  }
> -  return Offset;
> -}
> -
> -/// CompareMBBNumbers - Little predicate function to sort the WaterList by MBB
> -/// ID.
> -static bool CompareMBBNumbers(const MachineBasicBlock *LHS,
> -                              const MachineBasicBlock *RHS) {
> -  return LHS->getNumber() < RHS->getNumber();
> -}
> -
> -/// updateForInsertedWaterBlock - When a block is newly inserted into the
> -/// machine function, it upsets all of the block numbers.  Renumber the blocks
> -/// and update the arrays that parallel this numbering.
> -void MipsConstantIslands::updateForInsertedWaterBlock(MachineBasicBlock *NewBB) {
> -  // Renumber the MBB's to keep them consecutive.
> -  NewBB->getParent()->RenumberBlocks(NewBB);
> -
> -  // Insert an entry into BBInfo to align it properly with the (newly
> -  // renumbered) block numbers.
> -  BBInfo.insert(BBInfo.begin() + NewBB->getNumber(), BasicBlockInfo());
> -
> -  // Next, update WaterList.  Specifically, we need to add NewMBB as having
> -  // available water after it.
> -  water_iterator IP =
> -    std::lower_bound(WaterList.begin(), WaterList.end(), NewBB,
> -                     CompareMBBNumbers);
> -  WaterList.insert(IP, NewBB);
> -}
> -
> -/// getUserOffset - Compute the offset of U.MI as seen by the hardware
> -/// displacement computation.  Update U.KnownAlignment to match its current
> -/// basic block location.
> -unsigned MipsConstantIslands::getUserOffset(CPUser &U) const {
> -  unsigned UserOffset = getOffsetOf(U.MI);
> -  const BasicBlockInfo &BBI = BBInfo[U.MI->getParent()->getNumber()];
> -  unsigned KnownBits = BBI.internalKnownBits();
> -
> -  // The value read from PC is offset from the actual instruction address.
> -#ifdef IN_PROGRESS
> -  UserOffset += (isThumb ? 4 : 8);
> -#endif
> -
> -  // Because of inline assembly, we may not know the alignment (mod 4) of U.MI.
> -  // Make sure U.getMaxDisp() returns a constrained range.
> -  U.KnownAlignment = (KnownBits >= 2);
> -
> -  // On Thumb, offsets==2 mod 4 are rounded down by the hardware for
> -  // purposes of the displacement computation; compensate for that here.
> -  // For unknown alignments, getMaxDisp() constrains the range instead.
> -#ifdef IN_PROGRESS
> -  if (isThumb && U.KnownAlignment)
> -    UserOffset &= ~3u;
> -#endif
> -
> -  return UserOffset;
> -}
> -
> -/// Split the basic block containing MI into two blocks, which are joined by
> -/// an unconditional branch.  Update data structures and renumber blocks to
> -/// account for this change and returns the newly created block.
> -MachineBasicBlock *MipsConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) {
> -  MachineBasicBlock *OrigBB = MI->getParent();
> -
> -  // Create a new MBB for the code after the OrigBB.
> -  MachineBasicBlock *NewBB =
> -    MF->CreateMachineBasicBlock(OrigBB->getBasicBlock());
> -  MachineFunction::iterator MBBI = OrigBB; ++MBBI;
> -  MF->insert(MBBI, NewBB);
> -
> -  // Splice the instructions starting with MI over to NewBB.
> -  NewBB->splice(NewBB->end(), OrigBB, MI, OrigBB->end());
> -
> -  // Add an unconditional branch from OrigBB to NewBB.
> -  // Note the new unconditional branch is not being recorded.
> -  // There doesn't seem to be meaningful DebugInfo available; this doesn't
> -  // correspond to anything in the source.
> -  BuildMI(OrigBB, DebugLoc(), TII->get(Mips::BimmX16)).addMBB(NewBB);
> -#ifdef IN_PROGRESS
> -  unsigned Opc = isThumb ? (isThumb2 ? ARM::t2B : ARM::tB) : ARM::B;
> -  if (!isThumb)
> -    BuildMI(OrigBB, DebugLoc(), TII->get(Opc)).addMBB(NewBB);
> -  else
> -    BuildMI(OrigBB, DebugLoc(), TII->get(Opc)).addMBB(NewBB)
> -            .addImm(ARMCC::AL).addReg(0);
> -#endif
> -  ++NumSplit;
> -
> -  // Update the CFG.  All succs of OrigBB are now succs of NewBB.
> -  NewBB->transferSuccessors(OrigBB);
> -
> -  // OrigBB branches to NewBB.
> -  OrigBB->addSuccessor(NewBB);
> -
> -  // Update internal data structures to account for the newly inserted MBB.
> -  // This is almost the same as updateForInsertedWaterBlock, except that
> -  // the Water goes after OrigBB, not NewBB.
> -  MF->RenumberBlocks(NewBB);
> -
> -  // Insert an entry into BBInfo to align it properly with the (newly
> -  // renumbered) block numbers.
> -  BBInfo.insert(BBInfo.begin() + NewBB->getNumber(), BasicBlockInfo());
> -
> -  // Next, update WaterList.  Specifically, we need to add OrigMBB as having
> -  // available water after it (but not if it's already there, which happens
> -  // when splitting before a conditional branch that is followed by an
> -  // unconditional branch - in that case we want to insert NewBB).
> -  water_iterator IP =
> -    std::lower_bound(WaterList.begin(), WaterList.end(), OrigBB,
> -                     CompareMBBNumbers);
> -  MachineBasicBlock* WaterBB = *IP;
> -  if (WaterBB == OrigBB)
> -    WaterList.insert(llvm::next(IP), NewBB);
> -  else
> -    WaterList.insert(IP, OrigBB);
> -  NewWaterList.insert(OrigBB);
> -
> -  // Figure out how large the OrigBB is.  As the first half of the original
> -  // block, it cannot contain a tablejump.  The size includes
> -  // the new jump we added.  (It should be possible to do this without
> -  // recounting everything, but it's very confusing, and this is rarely
> -  // executed.)
> -  computeBlockSize(OrigBB);
> -
> -  // Figure out how large the NewMBB is.  As the second half of the original
> -  // block, it may contain a tablejump.
> -  computeBlockSize(NewBB);
> -
> -  // All BBOffsets following these blocks must be modified.
> -  adjustBBOffsetsAfter(OrigBB);
> -
> -  return NewBB;
> -}
> -
> -#ifndef NDEBUG
> -
> -
> -/// isOffsetInRange - Checks whether UserOffset (the location of a constant pool
> -/// reference) is within MaxDisp of TrialOffset (a proposed location of a
> -/// constant pool entry).
> -/// UserOffset is computed by getUserOffset above to include PC adjustments. If
> -/// the mod 4 alignment of UserOffset is not known, the uncertainty must be
> -/// subtracted from MaxDisp instead. CPUser::getMaxDisp() does that.
> -bool MipsConstantIslands::isOffsetInRange(unsigned UserOffset,
> -                                         unsigned TrialOffset, unsigned MaxDisp,
> -                                         bool NegativeOK, bool IsSoImm) {
> -  if (UserOffset <= TrialOffset) {
> -    // User before the Trial.
> -    if (TrialOffset - UserOffset <= MaxDisp)
> -      return true;
> -    // FIXME: Make use full range of soimm values.
> -  } else if (NegativeOK) {
> -    if (UserOffset - TrialOffset <= MaxDisp)
> -      return true;
> -    // FIXME: Make use full range of soimm values.
> -  }
> -  return false;
> -}
> -
> -/// isWaterInRange - Returns true if a CPE placed after the specified
> -/// Water (a basic block) will be in range for the specific MI.
> -///
> -/// Compute how much the function will grow by inserting a CPE after Water.
> -bool MipsConstantIslands::isWaterInRange(unsigned UserOffset,
> -                                        MachineBasicBlock* Water, CPUser &U,
> -                                        unsigned &Growth) {
> -  unsigned CPELogAlign = getCPELogAlign(U.CPEMI);
> -  unsigned CPEOffset = BBInfo[Water->getNumber()].postOffset(CPELogAlign);
> -  unsigned NextBlockOffset, NextBlockAlignment;
> -  MachineFunction::const_iterator NextBlock = Water;
> -  if (++NextBlock == MF->end()) {
> -    NextBlockOffset = BBInfo[Water->getNumber()].postOffset();
> -    NextBlockAlignment = 0;
> -  } else {
> -    NextBlockOffset = BBInfo[NextBlock->getNumber()].Offset;
> -    NextBlockAlignment = NextBlock->getAlignment();
> -  }
> -  unsigned Size = U.CPEMI->getOperand(2).getImm();
> -  unsigned CPEEnd = CPEOffset + Size;
> -
> -  // The CPE may be able to hide in the alignment padding before the next
> -  // block. It may also cause more padding to be required if it is more aligned
> -  // that the next block.
> -  if (CPEEnd > NextBlockOffset) {
> -    Growth = CPEEnd - NextBlockOffset;
> -    // Compute the padding that would go at the end of the CPE to align the next
> -    // block.
> -    Growth += OffsetToAlignment(CPEEnd, 1u << NextBlockAlignment);
> -
> -    // If the CPE is to be inserted before the instruction, that will raise
> -    // the offset of the instruction. Also account for unknown alignment padding
> -    // in blocks between CPE and the user.
> -    if (CPEOffset < UserOffset)
> -      UserOffset += Growth + UnknownPadding(MF->getAlignment(), CPELogAlign);
> -  } else
> -    // CPE fits in existing padding.
> -    Growth = 0;
> -
> -  return isOffsetInRange(UserOffset, CPEOffset, U);
> -}
> -
> -/// isCPEntryInRange - Returns true if the distance between specific MI and
> -/// specific ConstPool entry instruction can fit in MI's displacement field.
> -bool MipsConstantIslands::isCPEntryInRange(MachineInstr *MI, unsigned UserOffset,
> -                                      MachineInstr *CPEMI, unsigned MaxDisp,
> -                                      bool NegOk, bool DoDump) {
> -  unsigned CPEOffset  = getOffsetOf(CPEMI);
> -
> -  if (DoDump) {
> -    DEBUG({
> -      unsigned Block = MI->getParent()->getNumber();
> -      const BasicBlockInfo &BBI = BBInfo[Block];
> -      dbgs() << "User of CPE#" << CPEMI->getOperand(0).getImm()
> -             << " max delta=" << MaxDisp
> -             << format(" insn address=%#x", UserOffset)
> -             << " in BB#" << Block << ": "
> -             << format("%#x-%x\t", BBI.Offset, BBI.postOffset()) << *MI
> -             << format("CPE address=%#x offset=%+d: ", CPEOffset,
> -                       int(CPEOffset-UserOffset));
> -    });
> -  }
> -
> -  return isOffsetInRange(UserOffset, CPEOffset, MaxDisp, NegOk);
> -}
> -
> -/// BBIsJumpedOver - Return true of the specified basic block's only predecessor
> -/// unconditionally branches to its only successor.
> -static bool BBIsJumpedOver(MachineBasicBlock *MBB) {
> -  if (MBB->pred_size() != 1 || MBB->succ_size() != 1)
> -    return false;
> -
> -#ifdef IN_PROGRESS
> -  MachineBasicBlock *Succ = *MBB->succ_begin();
> -  MachineBasicBlock *Pred = *MBB->pred_begin();
> -  MachineInstr *PredMI = &Pred->back();
> -  if (PredMI->getOpcode() == ARM::B || PredMI->getOpcode() == ARM::tB
> -      || PredMI->getOpcode() == ARM::t2B)
> -    return PredMI->getOperand(0).getMBB() == Succ;
> -#endif
> -  return false;
> -}
> -#endif // NDEBUG
> -
> -void MipsConstantIslands::adjustBBOffsetsAfter(MachineBasicBlock *BB) {
> -  unsigned BBNum = BB->getNumber();
> -  for(unsigned i = BBNum + 1, e = MF->getNumBlockIDs(); i < e; ++i) {
> -    // Get the offset and known bits at the end of the layout predecessor.
> -    // Include the alignment of the current block.
> -    unsigned Offset = BBInfo[i - 1].postOffset();
> -    BBInfo[i].Offset = Offset;
> -  }
> -}
> -
> -/// decrementCPEReferenceCount - find the constant pool entry with index CPI
> -/// and instruction CPEMI, and decrement its refcount.  If the refcount
> -/// becomes 0 remove the entry and instruction.  Returns true if we removed
> -/// the entry, false if we didn't.
> -
> -bool MipsConstantIslands::decrementCPEReferenceCount(unsigned CPI,
> -                                                    MachineInstr *CPEMI) {
> -  // Find the old entry. Eliminate it if it is no longer used.
> -  CPEntry *CPE = findConstPoolEntry(CPI, CPEMI);
> -  assert(CPE && "Unexpected!");
> -  if (--CPE->RefCount == 0) {
> -    removeDeadCPEMI(CPEMI);
> -    CPE->CPEMI = NULL;
> -    --NumCPEs;
> -    return true;
> -  }
> -  return false;
> -}
> -
> -/// LookForCPEntryInRange - see if the currently referenced CPE is in range;
> -/// if not, see if an in-range clone of the CPE is in range, and if so,
> -/// change the data structures so the user references the clone.  Returns:
> -/// 0 = no existing entry found
> -/// 1 = entry found, and there were no code insertions or deletions
> -/// 2 = entry found, and there were code insertions or deletions
> -int MipsConstantIslands::findInRangeCPEntry(CPUser& U, unsigned UserOffset)
> -{
> -  MachineInstr *UserMI = U.MI;
> -  MachineInstr *CPEMI  = U.CPEMI;
> -
> -  // Check to see if the CPE is already in-range.
> -  if (isCPEntryInRange(UserMI, UserOffset, CPEMI, U.getMaxDisp(), U.NegOk,
> -                       true)) {
> -    DEBUG(dbgs() << "In range\n");
> -    return 1;
> -  }
> -
> -  // No.  Look for previously created clones of the CPE that are in range.
> -  unsigned CPI = CPEMI->getOperand(1).getIndex();
> -  std::vector<CPEntry> &CPEs = CPEntries[CPI];
> -  for (unsigned i = 0, e = CPEs.size(); i != e; ++i) {
> -    // We already tried this one
> -    if (CPEs[i].CPEMI == CPEMI)
> -      continue;
> -    // Removing CPEs can leave empty entries, skip
> -    if (CPEs[i].CPEMI == NULL)
> -      continue;
> -    if (isCPEntryInRange(UserMI, UserOffset, CPEs[i].CPEMI, U.getMaxDisp(),
> -                     U.NegOk)) {
> -      DEBUG(dbgs() << "Replacing CPE#" << CPI << " with CPE#"
> -                   << CPEs[i].CPI << "\n");
> -      // Point the CPUser node to the replacement
> -      U.CPEMI = CPEs[i].CPEMI;
> -      // Change the CPI in the instruction operand to refer to the clone.
> -      for (unsigned j = 0, e = UserMI->getNumOperands(); j != e; ++j)
> -        if (UserMI->getOperand(j).isCPI()) {
> -          UserMI->getOperand(j).setIndex(CPEs[i].CPI);
> -          break;
> -        }
> -      // Adjust the refcount of the clone...
> -      CPEs[i].RefCount++;
> -      // ...and the original.  If we didn't remove the old entry, none of the
> -      // addresses changed, so we don't need another pass.
> -      return decrementCPEReferenceCount(CPI, CPEMI) ? 2 : 1;
> -    }
> -  }
> -  return 0;
> -}
> -
> -/// LookForCPEntryInRange - see if the currently referenced CPE is in range;
> -/// This version checks if the longer form of the instruction can be used to
> -/// to satisfy things.
> -/// if not, see if an in-range clone of the CPE is in range, and if so,
> -/// change the data structures so the user references the clone.  Returns:
> -/// 0 = no existing entry found
> -/// 1 = entry found, and there were no code insertions or deletions
> -/// 2 = entry found, and there were code insertions or deletions
> -int MipsConstantIslands::findLongFormInRangeCPEntry(CPUser& U, unsigned UserOffset)
> -{
> -  MachineInstr *UserMI = U.MI;
> -  MachineInstr *CPEMI  = U.CPEMI;
> -
> -  // Check to see if the CPE is already in-range.
> -  if (isCPEntryInRange(UserMI, UserOffset, CPEMI, U.getLongFormMaxDisp(), U.NegOk,
> -                       true)) {
> -    DEBUG(dbgs() << "In range\n");
> -    UserMI->setDesc(TII->get(U.getLongFormOpcode()));
> -    return 2;  // instruction is longer length now
> -  }
> -
> -  // No.  Look for previously created clones of the CPE that are in range.
> -  unsigned CPI = CPEMI->getOperand(1).getIndex();
> -  std::vector<CPEntry> &CPEs = CPEntries[CPI];
> -  for (unsigned i = 0, e = CPEs.size(); i != e; ++i) {
> -    // We already tried this one
> -    if (CPEs[i].CPEMI == CPEMI)
> -      continue;
> -    // Removing CPEs can leave empty entries, skip
> -    if (CPEs[i].CPEMI == NULL)
> -      continue;
> -    if (isCPEntryInRange(UserMI, UserOffset, CPEs[i].CPEMI, U.getLongFormMaxDisp(),
> -                     U.NegOk)) {
> -      DEBUG(dbgs() << "Replacing CPE#" << CPI << " with CPE#"
> -                   << CPEs[i].CPI << "\n");
> -      // Point the CPUser node to the replacement
> -      U.CPEMI = CPEs[i].CPEMI;
> -      // Change the CPI in the instruction operand to refer to the clone.
> -      for (unsigned j = 0, e = UserMI->getNumOperands(); j != e; ++j)
> -        if (UserMI->getOperand(j).isCPI()) {
> -          UserMI->getOperand(j).setIndex(CPEs[i].CPI);
> -          break;
> -        }
> -      // Adjust the refcount of the clone...
> -      CPEs[i].RefCount++;
> -      // ...and the original.  If we didn't remove the old entry, none of the
> -      // addresses changed, so we don't need another pass.
> -      return decrementCPEReferenceCount(CPI, CPEMI) ? 2 : 1;
> -    }
> -  }
> -  return 0;
> -}
> -
> -/// getUnconditionalBrDisp - Returns the maximum displacement that can fit in
> -/// the specific unconditional branch instruction.
> -static inline unsigned getUnconditionalBrDisp(int Opc) {
> -#ifdef IN_PROGRESS
> -  switch (Opc) {
> -  case ARM::tB:
> -    return ((1<<10)-1)*2;
> -  case ARM::t2B:
> -    return ((1<<23)-1)*2;
> -  default:
> -    break;
> -  }
> -#endif
> -  return ((1<<23)-1)*4;
> -}
> -
> -/// findAvailableWater - Look for an existing entry in the WaterList in which
> -/// we can place the CPE referenced from U so it's within range of U's MI.
> -/// Returns true if found, false if not.  If it returns true, WaterIter
> -/// is set to the WaterList entry.  For Thumb, prefer water that will not
> -/// introduce padding to water that will.  To ensure that this pass
> -/// terminates, the CPE location for a particular CPUser is only allowed to
> -/// move to a lower address, so search backward from the end of the list and
> -/// prefer the first water that is in range.
> -bool MipsConstantIslands::findAvailableWater(CPUser &U, unsigned UserOffset,
> -                                      water_iterator &WaterIter) {
> -  if (WaterList.empty())
> -    return false;
> -
> -  unsigned BestGrowth = ~0u;
> -  for (water_iterator IP = prior(WaterList.end()), B = WaterList.begin();;
> -       --IP) {
> -    MachineBasicBlock* WaterBB = *IP;
> -    // Check if water is in range and is either at a lower address than the
> -    // current "high water mark" or a new water block that was created since
> -    // the previous iteration by inserting an unconditional branch.  In the
> -    // latter case, we want to allow resetting the high water mark back to
> -    // this new water since we haven't seen it before.  Inserting branches
> -    // should be relatively uncommon and when it does happen, we want to be
> -    // sure to take advantage of it for all the CPEs near that block, so that
> -    // we don't insert more branches than necessary.
> -    unsigned Growth;
> -    if (isWaterInRange(UserOffset, WaterBB, U, Growth) &&
> -        (WaterBB->getNumber() < U.HighWaterMark->getNumber() ||
> -         NewWaterList.count(WaterBB)) && Growth < BestGrowth) {
> -      // This is the least amount of required padding seen so far.
> -      BestGrowth = Growth;
> -      WaterIter = IP;
> -      DEBUG(dbgs() << "Found water after BB#" << WaterBB->getNumber()
> -                   << " Growth=" << Growth << '\n');
> -
> -      // Keep looking unless it is perfect.
> -      if (BestGrowth == 0)
> -        return true;
> -    }
> -    if (IP == B)
> -      break;
> -  }
> -  return BestGrowth != ~0u;
> -}
> -
> -/// createNewWater - No existing WaterList entry will work for
> -/// CPUsers[CPUserIndex], so create a place to put the CPE.  The end of the
> -/// block is used if in range, and the conditional branch munged so control
> -/// flow is correct.  Otherwise the block is split to create a hole with an
> -/// unconditional branch around it.  In either case NewMBB is set to a
> -/// block following which the new island can be inserted (the WaterList
> -/// is not adjusted).
> -void MipsConstantIslands::createNewWater(unsigned CPUserIndex,
> -                                        unsigned UserOffset,
> -                                        MachineBasicBlock *&NewMBB) {
> -  CPUser &U = CPUsers[CPUserIndex];
> -  MachineInstr *UserMI = U.MI;
> -  MachineInstr *CPEMI  = U.CPEMI;
> -  unsigned CPELogAlign = getCPELogAlign(CPEMI);
> -  MachineBasicBlock *UserMBB = UserMI->getParent();
> -  const BasicBlockInfo &UserBBI = BBInfo[UserMBB->getNumber()];
> -
> -  // If the block does not end in an unconditional branch already, and if the
> -  // end of the block is within range, make new water there.  (The addition
> -  // below is for the unconditional branch we will be adding: 4 bytes on ARM +
> -  // Thumb2, 2 on Thumb1.
> -  if (BBHasFallthrough(UserMBB)) {
> -    // Size of branch to insert.
> -#ifdef IN_PROGRESS
> -    unsigned Delta = isThumb1 ? 2 : 4;
> -#else
> -    unsigned Delta = 4;
> -#endif
> -    // Compute the offset where the CPE will begin.
> -    unsigned CPEOffset = UserBBI.postOffset(CPELogAlign) + Delta;
> -
> -    if (isOffsetInRange(UserOffset, CPEOffset, U)) {
> -      DEBUG(dbgs() << "Split at end of BB#" << UserMBB->getNumber()
> -            << format(", expected CPE offset %#x\n", CPEOffset));
> -      NewMBB = llvm::next(MachineFunction::iterator(UserMBB));
> -      // Add an unconditional branch from UserMBB to fallthrough block.  Record
> -      // it for branch lengthening; this new branch will not get out of range,
> -      // but if the preceding conditional branch is out of range, the targets
> -      // will be exchanged, and the altered branch may be out of range, so the
> -      // machinery has to know about it.
> -#ifdef IN_PROGRESS
> -      int UncondBr = isThumb ? ((isThumb2) ? ARM::t2B : ARM::tB) : ARM::B;
> -      if (!isThumb)
> -        BuildMI(UserMBB, DebugLoc(), TII->get(UncondBr)).addMBB(NewMBB);
> -      else
> -        BuildMI(UserMBB, DebugLoc(), TII->get(UncondBr)).addMBB(NewMBB)
> -          .addImm(ARMCC::AL).addReg(0);
> -#else
> -      int UncondBr = 1;
> -#endif
> -      unsigned MaxDisp = getUnconditionalBrDisp(UncondBr);
> -      ImmBranches.push_back(ImmBranch(&UserMBB->back(),
> -                                      MaxDisp, false, UncondBr));
> -      BBInfo[UserMBB->getNumber()].Size += Delta;
> -      adjustBBOffsetsAfter(UserMBB);
> -      return;
> -    }
> -  }
> -
> -  // What a big block.  Find a place within the block to split it.  This is a
> -  // little tricky on Thumb1 since instructions are 2 bytes and constant pool
> -  // entries are 4 bytes: if instruction I references island CPE, and
> -  // instruction I+1 references CPE', it will not work well to put CPE as far
> -  // forward as possible, since then CPE' cannot immediately follow it (that
> -  // location is 2 bytes farther away from I+1 than CPE was from I) and we'd
> -  // need to create a new island.  So, we make a first guess, then walk through
> -  // the instructions between the one currently being looked at and the
> -  // possible insertion point, and make sure any other instructions that
> -  // reference CPEs will be able to use the same island area; if not, we back
> -  // up the insertion point.
> -
> -  // Try to split the block so it's fully aligned.  Compute the latest split
> -  // point where we can add a 4-byte branch instruction, and then align to
> -  // LogAlign which is the largest possible alignment in the function.
> -  unsigned LogAlign = MF->getAlignment();
> -  assert(LogAlign >= CPELogAlign && "Over-aligned constant pool entry");
> -  unsigned KnownBits = UserBBI.internalKnownBits();
> -  unsigned UPad = UnknownPadding(LogAlign, KnownBits);
> -  unsigned BaseInsertOffset = UserOffset + U.getMaxDisp() - UPad;
> -  DEBUG(dbgs() << format("Split in middle of big block before %#x",
> -                         BaseInsertOffset));
> -
> -  // The 4 in the following is for the unconditional branch we'll be inserting
> -  // (allows for long branch on Thumb1).  Alignment of the island is handled
> -  // inside isOffsetInRange.
> -  BaseInsertOffset -= 4;
> -
> -  DEBUG(dbgs() << format(", adjusted to %#x", BaseInsertOffset)
> -               << " la=" << LogAlign
> -               << " kb=" << KnownBits
> -               << " up=" << UPad << '\n');
> -
> -  // This could point off the end of the block if we've already got constant
> -  // pool entries following this block; only the last one is in the water list.
> -  // Back past any possible branches (allow for a conditional and a maximally
> -  // long unconditional).
> -  if (BaseInsertOffset + 8 >= UserBBI.postOffset()) {
> -    BaseInsertOffset = UserBBI.postOffset() - UPad - 8;
> -    DEBUG(dbgs() << format("Move inside block: %#x\n", BaseInsertOffset));
> -  }
> -  unsigned EndInsertOffset = BaseInsertOffset + 4 + UPad +
> -    CPEMI->getOperand(2).getImm();
> -  MachineBasicBlock::iterator MI = UserMI;
> -  ++MI;
> -  unsigned CPUIndex = CPUserIndex+1;
> -  unsigned NumCPUsers = CPUsers.size();
> -  MachineInstr *LastIT = 0;
> -  for (unsigned Offset = UserOffset+TII->GetInstSizeInBytes(UserMI);
> -       Offset < BaseInsertOffset;
> -       Offset += TII->GetInstSizeInBytes(MI),
> -       MI = llvm::next(MI)) {
> -    assert(MI != UserMBB->end() && "Fell off end of block");
> -    if (CPUIndex < NumCPUsers && CPUsers[CPUIndex].MI == MI) {
> -      CPUser &U = CPUsers[CPUIndex];
> -      if (!isOffsetInRange(Offset, EndInsertOffset, U)) {
> -        // Shift intertion point by one unit of alignment so it is within reach.
> -        BaseInsertOffset -= 1u << LogAlign;
> -        EndInsertOffset  -= 1u << LogAlign;
> -      }
> -      // This is overly conservative, as we don't account for CPEMIs being
> -      // reused within the block, but it doesn't matter much.  Also assume CPEs
> -      // are added in order with alignment padding.  We may eventually be able
> -      // to pack the aligned CPEs better.
> -      EndInsertOffset += U.CPEMI->getOperand(2).getImm();
> -      CPUIndex++;
> -    }
> -#ifdef IN_PROGRESS
> -    // Remember the last IT instruction.
> -    if (MI->getOpcode() == ARM::t2IT)
> -      LastIT = MI;
> -#endif
> -  }
> -
> -  --MI;
> -
> -  // Avoid splitting an IT block.
> -  if (LastIT) {
> -#ifdef IN_PROGRESS
> -    unsigned PredReg = 0;
> -    ARMCC::CondCodes CC = getITInstrPredicate(MI, PredReg);
> -    if (CC != ARMCC::AL)
> -      MI = LastIT;
> -#endif
> -  }
> -  NewMBB = splitBlockBeforeInstr(MI);
> -}
> -
> -/// handleConstantPoolUser - Analyze the specified user, checking to see if it
> -/// is out-of-range.  If so, pick up the constant pool value and move it some
> -/// place in-range.  Return true if we changed any addresses (thus must run
> -/// another pass of branch lengthening), false otherwise.
> -bool MipsConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) {
> -  CPUser &U = CPUsers[CPUserIndex];
> -  MachineInstr *UserMI = U.MI;
> -  MachineInstr *CPEMI  = U.CPEMI;
> -  unsigned CPI = CPEMI->getOperand(1).getIndex();
> -  unsigned Size = CPEMI->getOperand(2).getImm();
> -  // Compute this only once, it's expensive.
> -  unsigned UserOffset = getUserOffset(U);
> -
> -  // See if the current entry is within range, or there is a clone of it
> -  // in range.
> -  int result = findInRangeCPEntry(U, UserOffset);
> -  if (result==1) return false;
> -  else if (result==2) return true;
> -
> -
> -  // Look for water where we can place this CPE.
> -  MachineBasicBlock *NewIsland = MF->CreateMachineBasicBlock();
> -  MachineBasicBlock *NewMBB;
> -  water_iterator IP;
> -  if (findAvailableWater(U, UserOffset, IP)) {
> -    DEBUG(dbgs() << "Found water in range\n");
> -    MachineBasicBlock *WaterBB = *IP;
> -
> -    // If the original WaterList entry was "new water" on this iteration,
> -    // propagate that to the new island.  This is just keeping NewWaterList
> -    // updated to match the WaterList, which will be updated below.
> -    if (NewWaterList.erase(WaterBB))
> -      NewWaterList.insert(NewIsland);
> -
> -    // The new CPE goes before the following block (NewMBB).
> -    NewMBB = llvm::next(MachineFunction::iterator(WaterBB));
> -
> -  } else {
> -    // No water found.
> -    // we first see if a longer form of the instrucion could have reached the constant.
> -    // in that case we won't bother to split
> -#ifdef IN_PROGRESS
> -    result = findLongFormInRangeCPEntry(U, UserOffset);
> -#endif
> -    DEBUG(dbgs() << "No water found\n");
> -    createNewWater(CPUserIndex, UserOffset, NewMBB);
> -
> -    // splitBlockBeforeInstr adds to WaterList, which is important when it is
> -    // called while handling branches so that the water will be seen on the
> -    // next iteration for constant pools, but in this context, we don't want
> -    // it.  Check for this so it will be removed from the WaterList.
> -    // Also remove any entry from NewWaterList.
> -    MachineBasicBlock *WaterBB = prior(MachineFunction::iterator(NewMBB));
> -    IP = std::find(WaterList.begin(), WaterList.end(), WaterBB);
> -    if (IP != WaterList.end())
> -      NewWaterList.erase(WaterBB);
> -
> -    // We are adding new water.  Update NewWaterList.
> -    NewWaterList.insert(NewIsland);
> -  }
> -
> -  // Remove the original WaterList entry; we want subsequent insertions in
> -  // this vicinity to go after the one we're about to insert.  This
> -  // considerably reduces the number of times we have to move the same CPE
> -  // more than once and is also important to ensure the algorithm terminates.
> -  if (IP != WaterList.end())
> -    WaterList.erase(IP);
> -
> -  // Okay, we know we can put an island before NewMBB now, do it!
> -  MF->insert(NewMBB, NewIsland);
> -
> -  // Update internal data structures to account for the newly inserted MBB.
> -  updateForInsertedWaterBlock(NewIsland);
> -
> -  // Decrement the old entry, and remove it if refcount becomes 0.
> -  decrementCPEReferenceCount(CPI, CPEMI);
> -
> -  // Now that we have an island to add the CPE to, clone the original CPE and
> -  // add it to the island.
> -  U.HighWaterMark = NewIsland;
> -  U.CPEMI = BuildMI(NewIsland, DebugLoc(), TII->get(Mips::CONSTPOOL_ENTRY))
> -                .addImm(ID).addConstantPoolIndex(CPI).addImm(Size);
> -  CPEntries[CPI].push_back(CPEntry(U.CPEMI, ID, 1));
> -  ++NumCPEs;
> -
> -  // Mark the basic block as aligned as required by the const-pool entry.
> -  NewIsland->setAlignment(getCPELogAlign(U.CPEMI));
> -
> -  // Increase the size of the island block to account for the new entry.
> -  BBInfo[NewIsland->getNumber()].Size += Size;
> -  adjustBBOffsetsAfter(llvm::prior(MachineFunction::iterator(NewIsland)));
> -
> -  // No existing clone of this CPE is within range.
> -  // We will be generating a new clone.  Get a UID for it.
> -  unsigned ID = createPICLabelUId();
> -
> -  // Finally, change the CPI in the instruction operand to be ID.
> -  for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i)
> -    if (UserMI->getOperand(i).isCPI()) {
> -      UserMI->getOperand(i).setIndex(ID);
> -      break;
> -    }
> -
> -  DEBUG(dbgs() << "  Moved CPE to #" << ID << " CPI=" << CPI
> -        << format(" offset=%#x\n", BBInfo[NewIsland->getNumber()].Offset));
> -
> -  return true;
> -}
> -
> -/// removeDeadCPEMI - Remove a dead constant pool entry instruction. Update
> -/// sizes and offsets of impacted basic blocks.
> -void MipsConstantIslands::removeDeadCPEMI(MachineInstr *CPEMI) {
> -  MachineBasicBlock *CPEBB = CPEMI->getParent();
> -  unsigned Size = CPEMI->getOperand(2).getImm();
> -  CPEMI->eraseFromParent();
> -  BBInfo[CPEBB->getNumber()].Size -= Size;
> -  // All succeeding offsets have the current size value added in, fix this.
> -  if (CPEBB->empty()) {
> -    BBInfo[CPEBB->getNumber()].Size = 0;
> -
> -    // This block no longer needs to be aligned.
> -    CPEBB->setAlignment(0);
> -  } else
> -    // Entries are sorted by descending alignment, so realign from the front.
> -    CPEBB->setAlignment(getCPELogAlign(CPEBB->begin()));
> -
> -  adjustBBOffsetsAfter(CPEBB);
> -  // An island has only one predecessor BB and one successor BB. Check if
> -  // this BB's predecessor jumps directly to this BB's successor. This
> -  // shouldn't happen currently.
> -  assert(!BBIsJumpedOver(CPEBB) && "How did this happen?");
> -  // FIXME: remove the empty blocks after all the work is done?
> -}
> -
> -/// removeUnusedCPEntries - Remove constant pool entries whose refcounts
> -/// are zero.
> -bool MipsConstantIslands::removeUnusedCPEntries() {
> -  unsigned MadeChange = false;
> -  for (unsigned i = 0, e = CPEntries.size(); i != e; ++i) {
> -      std::vector<CPEntry> &CPEs = CPEntries[i];
> -      for (unsigned j = 0, ee = CPEs.size(); j != ee; ++j) {
> -        if (CPEs[j].RefCount == 0 && CPEs[j].CPEMI) {
> -          removeDeadCPEMI(CPEs[j].CPEMI);
> -          CPEs[j].CPEMI = NULL;
> -          MadeChange = true;
> -        }
> -      }
> -  }
> -  return MadeChange;
> -}
> -
> -/// isBBInRange - Returns true if the distance between specific MI and
> -/// specific BB can fit in MI's displacement field.
> -bool MipsConstantIslands::isBBInRange(MachineInstr *MI,MachineBasicBlock *DestBB,
> -                                     unsigned MaxDisp) {
> -#ifdef IN_PROGRESS
> -  unsigned PCAdj      = isThumb ? 4 : 8;
> -#else
> -  unsigned PCAdj = 4;
> -#endif
> -  unsigned BrOffset   = getOffsetOf(MI) + PCAdj;
> -  unsigned DestOffset = BBInfo[DestBB->getNumber()].Offset;
> -
> -  DEBUG(dbgs() << "Branch of destination BB#" << DestBB->getNumber()
> -               << " from BB#" << MI->getParent()->getNumber()
> -               << " max delta=" << MaxDisp
> -               << " from " << getOffsetOf(MI) << " to " << DestOffset
> -               << " offset " << int(DestOffset-BrOffset) << "\t" << *MI);
> -
> -  if (BrOffset <= DestOffset) {
> -    // Branch before the Dest.
> -    if (DestOffset-BrOffset <= MaxDisp)
> -      return true;
> -  } else {
> -    if (BrOffset-DestOffset <= MaxDisp)
> -      return true;
> -  }
> -  return false;
> -}
> -
> -/// fixupImmediateBr - Fix up an immediate branch whose destination is too far
> -/// away to fit in its displacement field.
> -bool MipsConstantIslands::fixupImmediateBr(ImmBranch &Br) {
> -  MachineInstr *MI = Br.MI;
> -  MachineBasicBlock *DestBB = MI->getOperand(0).getMBB();
> -
> -  // Check to see if the DestBB is already in-range.
> -  if (isBBInRange(MI, DestBB, Br.MaxDisp))
> -    return false;
> -
> -  if (!Br.isCond)
> -    return fixupUnconditionalBr(Br);
> -  return fixupConditionalBr(Br);
> -}
> -
> -/// fixupUnconditionalBr - Fix up an unconditional branch whose destination is
> -/// too far away to fit in its displacement field. If the LR register has been
> -/// spilled in the epilogue, then we can use BL to implement a far jump.
> -/// Otherwise, add an intermediate branch instruction to a branch.
> -bool
> -MipsConstantIslands::fixupUnconditionalBr(ImmBranch &Br) {
> -  MachineInstr *MI = Br.MI;
> -  MachineBasicBlock *MBB = MI->getParent();
> -#ifdef IN_PROGRESS
> -  if (!isThumb1)
> -    llvm_unreachable("fixupUnconditionalBr is Thumb1 only!");
> -#endif
> -  // Use BL to implement far jump.
> -  Br.MaxDisp = (1 << 21) * 2;
> -#ifdef IN_PROGRESS
> -  MI->setDesc(TII->get(ARM::tBfar));
> -#endif
> -  BBInfo[MBB->getNumber()].Size += 2;
> -  adjustBBOffsetsAfter(MBB);
> -  HasFarJump = true;
> -  ++NumUBrFixed;
> -
> -  DEBUG(dbgs() << "  Changed B to long jump " << *MI);
> -
> -  return true;
> -}
> -
> -/// fixupConditionalBr - Fix up a conditional branch whose destination is too
> -/// far away to fit in its displacement field. It is converted to an inverse
> -/// conditional branch + an unconditional branch to the destination.
> -bool
> -MipsConstantIslands::fixupConditionalBr(ImmBranch &Br) {
> -#ifdef IN_PROGRESS
> -  MachineInstr *MI = Br.MI;
> -  MachineBasicBlock *DestBB = MI->getOperand(0).getMBB();
> -
> -  // Add an unconditional branch to the destination and invert the branch
> -  // condition to jump over it:
> -  // blt L1
> -  // =>
> -  // bge L2
> -  // b   L1
> -  // L2:
> -  ARMCC::CondCodes CC = (ARMCC::CondCodes)MI->getOperand(1).getImm();
> -  CC = ARMCC::getOppositeCondition(CC);
> -  unsigned CCReg = MI->getOperand(2).getReg();
> -
> -  // If the branch is at the end of its MBB and that has a fall-through block,
> -  // direct the updated conditional branch to the fall-through block. Otherwise,
> -  // split the MBB before the next instruction.
> -  MachineBasicBlock *MBB = MI->getParent();
> -  MachineInstr *BMI = &MBB->back();
> -  bool NeedSplit = (BMI != MI) || !BBHasFallthrough(MBB);
> -
> -  ++NumCBrFixed;
> -  if (BMI != MI) {
> -    if (llvm::next(MachineBasicBlock::iterator(MI)) == prior(MBB->end()) &&
> -        BMI->getOpcode() == Br.UncondBr) {
> -      // Last MI in the BB is an unconditional branch. Can we simply invert the
> -      // condition and swap destinations:
> -      // beq L1
> -      // b   L2
> -      // =>
> -      // bne L2
> -      // b   L1
> -      MachineBasicBlock *NewDest = BMI->getOperand(0).getMBB();
> -      if (isBBInRange(MI, NewDest, Br.MaxDisp)) {
> -        DEBUG(dbgs() << "  Invert Bcc condition and swap its destination with "
> -                     << *BMI);
> -        BMI->getOperand(0).setMBB(DestBB);
> -        MI->getOperand(0).setMBB(NewDest);
> -        MI->getOperand(1).setImm(CC);
> -        return true;
> -      }
> -    }
> -  }
> -
> -  if (NeedSplit) {
> -    splitBlockBeforeInstr(MI);
> -    // No need for the branch to the next block. We're adding an unconditional
> -    // branch to the destination.
> -    int delta = TII->GetInstSizeInBytes(&MBB->back());
> -    BBInfo[MBB->getNumber()].Size -= delta;
> -    MBB->back().eraseFromParent();
> -    // BBInfo[SplitBB].Offset is wrong temporarily, fixed below
> -  }
> -  MachineBasicBlock *NextBB = llvm::next(MachineFunction::iterator(MBB));
> -
> -  DEBUG(dbgs() << "  Insert B to BB#" << DestBB->getNumber()
> -               << " also invert condition and change dest. to BB#"
> -               << NextBB->getNumber() << "\n");
> -
> -  // Insert a new conditional branch and a new unconditional branch.
> -  // Also update the ImmBranch as well as adding a new entry for the new branch.
> -  BuildMI(MBB, DebugLoc(), TII->get(MI->getOpcode()))
> -    .addMBB(NextBB).addImm(CC).addReg(CCReg);
> -  Br.MI = &MBB->back();
> -  BBInfo[MBB->getNumber()].Size += TII->GetInstSizeInBytes(&MBB->back());
> -  if (isThumb)
> -    BuildMI(MBB, DebugLoc(), TII->get(Br.UncondBr)).addMBB(DestBB)
> -            .addImm(ARMCC::AL).addReg(0);
> -  else
> -    BuildMI(MBB, DebugLoc(), TII->get(Br.UncondBr)).addMBB(DestBB);
> -  BBInfo[MBB->getNumber()].Size += TII->GetInstSizeInBytes(&MBB->back());
> -  unsigned MaxDisp = getUnconditionalBrDisp(Br.UncondBr);
> -  ImmBranches.push_back(ImmBranch(&MBB->back(), MaxDisp, false, Br.UncondBr));
> -
> -  // Remove the old conditional branch.  It may or may not still be in MBB.
> -  BBInfo[MI->getParent()->getNumber()].Size -= TII->GetInstSizeInBytes(MI);
> -  MI->eraseFromParent();
> -  adjustBBOffsetsAfter(MBB);
> -#endif
> -  return true;
> -}
> -
>
>   void MipsConstantIslands::prescanForConstants() {
>     unsigned int J;
> -  PrescannedForConstants = true;
>     for (MachineFunction::iterator B =
>            MF->begin(), E = MF->end(); B != E; ++B) {
>       for (MachineBasicBlock::instr_iterator I =
> @@ -1715,11 +238,10 @@ void MipsConstantIslands::prescanForCons
>               unsigned index = MCP->getConstantPoolIndex(C, 4);
>               I->getOperand(2).ChangeToImmediate(index);
>               DEBUG(dbgs() << "constant island constant " << *I << "\n");
> -            I->setDesc(TII->get(Mips::LwRxPcTcp16));
> +            I->setDesc(TII->get(Mips::LwRxPcTcpX16));
>               I->RemoveOperand(1);
>               I->RemoveOperand(1);
>               I->addOperand(MachineOperand::CreateCPI(index, 0));
> -            I->addOperand(MachineOperand::CreateImm(4));
>             }
>             break;
>           }
> @@ -1729,4 +251,3 @@ void MipsConstantIslands::prescanForCons
>       }
>     }
>   }
> -
>
> Removed: llvm/trunk/test/CodeGen/Mips/const4.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Mips/const4.ll?rev=194025&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/Mips/const4.ll (original)
> +++ llvm/trunk/test/CodeGen/Mips/const4.ll (removed)
> @@ -1,64 +0,0 @@
> -; RUN: llc -mtriple=mipsel-linux-gnu -march=mipsel -mcpu=mips16 -soft-float -mips16-hard-float -relocation-model=static -mips16-constant-islands -mips-constant-islands-small-offset=20  < %s | FileCheck %s -check-prefix=offset20
> -
> -; RUN: llc -mtriple=mipsel-linux-gnu -march=mipsel -mcpu=mips16 -soft-float -mips16-hard-float -relocation-model=static -mips16-constant-islands -mips-constant-islands-small-offset=40  < %s | FileCheck %s -check-prefix=offset40
> -
> -
> - at i = common global i32 0, align 4
> - at b = common global i32 0, align 4
> -
> -; Function Attrs: nounwind
> -define void @t() #0 {
> -entry:
> -  store i32 -559023410, i32* @i, align 4
> -  %0 = load i32* @b, align 4
> -  %tobool = icmp ne i32 %0, 0
> -  br i1 %tobool, label %if.then, label %if.else
> -; offset20: lw	${{[0-9]+}}, $CPI0_1	# 16 bit inst
> -; offset20:	b	$BB0_2
> -; offset20:	.align	2
> -; offset20: $CPI0_0:
> -; offset20:	.4byte	3735943886
> -; offset20: $BB0_2:
> -
> -; offset40:	beqz	${{[0-9]+}}, $BB0_3
> -; offset40:	jal	foo
> -; offset40:	nop
> -; offset40:	b	$BB0_4
> -; offset40:	.align	2
> -; offset40: $CPI0_0:
> -; offset40:	.4byte	3735943886
> -; offset40: $BB0_3:
> -; offset40:	jal	goo
> -
> -if.then:                                          ; preds = %entry
> -  call void bitcast (void (...)* @foo to void ()*)()
> -  br label %if.end
> -
> -if.else:                                          ; preds = %entry
> -  call void bitcast (void (...)* @goo to void ()*)()
> -  br label %if.end
> -
> -if.end:                                           ; preds = %if.else, %if.then
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  call void bitcast (void (...)* @hoo to void ()*)()
> -  ret void
> -}
> -
> -declare void @foo(...) #1
> -
> -declare void @goo(...) #1
> -
> -declare void @hoo(...) #1
> -
> -attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="true" }
> -attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="true" }
> -
> -!llvm.ident = !{!0}
> -
> -!0 = metadata !{metadata !"clang version 3.4 (gitosis-ePK3LoutQbwPXssp/fMQcEEOCMrvLtNR at public.gmane.org:clang.git 3a50d847e098f36e3bf8bc14eea07a6cc35f7803) (gitosis-ePK3LoutQbwPXssp/fMQcEEOCMrvLtNR at public.gmane.org:llvm.git f52db0b69f0c888bdc98bb2f13aaecc1e83288a9)"}
>





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