[llvm] r194026 - Revert r194019 to r194021, "Submit the basic port of the rest of ARM constant islands code to Mips."
NAKAMURA Takumi
geek4civic at gmail.com
Mon Nov 4 17:03:16 PST 2013
Reed, I am sorry, I supposed to send you an information, but I didn't send it.
You can reproduce with;
(autoconf) $ make DISABLE_ASSERTIONS=1
(cmake) -DLLVM_ENABLE_ASSERTIONS=OFF
I don't know whether the llvmlab has any builders with -Asserts.
FYI,
r194019 http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/6566
r194021 http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/6568
2013/11/5 reed kotler <rkotler at mips.com>:
> 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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