[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 17:43:48 PST 2013
On 11/04/2013 05:03 PM, NAKAMURA Takumi wrote:
> 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
I see the assert but it looks like a compiler bug to me.
That function is clearly defined.
I will try and workaround the problem.
llvm[2]: Linking Debug Shared Library libLTO.so
/usr/bin/ld:
/home/rkotler/llvmw/build/Debug/lib/libLLVMMipsCodeGen.a(MipsConstantIslandPass.o):
relocation R_X86_64_PC32 against undefined symbol `(anonymous
namespace)::MipsConstantIslands::isOffsetInRange(unsigned int, unsigned
int, unsigned int, bool, bool)' can not be used when making a shared
object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value
collect2: ld returned 1 exit status
make[2]: *** [/home/rkotler/llvmw/build/Debug/lib/libLTO.so] Error 1
make[2]: Leaving directory `/home/rkotler/llvmw/build/tools/lto'
make[1]: *** [all] Error 1
make[1]: Leaving directory `/home/rkotler/llvmw/build/tools'
make: *** [all] Error 1
rkotler at mipssw006:~/llvmw/build$
> 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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