2 //***************************************************************************
7 // Register allocation for LLVM.
10 // 9/10/01 - Ruchira Sasanka - created.
11 //**************************************************************************/
13 #include "llvm/CodeGen/PhyRegAlloc.h"
14 #include "llvm/CodeGen/MachineInstr.h"
15 #include "llvm/Target/TargetMachine.h"
16 #include "llvm/Target/MachineFrameInfo.h"
19 // ***TODO: There are several places we add instructions. Validate the order
20 // of adding these instructions.
24 cl::Enum<RegAllocDebugLevel_t> DEBUG_RA("dregalloc", cl::NoFlags,
25 "enable register allocation debugging information",
26 clEnumValN(RA_DEBUG_None , "n", "disable debug output"),
27 clEnumValN(RA_DEBUG_Normal , "y", "enable debug output"),
28 clEnumValN(RA_DEBUG_Verbose, "v", "enable extra debug output"), 0);
31 //----------------------------------------------------------------------------
32 // Constructor: Init local composite objects and create register classes.
33 //----------------------------------------------------------------------------
34 PhyRegAlloc::PhyRegAlloc(Method *M,
35 const TargetMachine& tm,
36 MethodLiveVarInfo *const Lvi)
40 mcInfo(MachineCodeForMethod::get(M)),
41 LVI(Lvi), LRI(M, tm, RegClassList),
42 MRI( tm.getRegInfo() ),
43 NumOfRegClasses(MRI.getNumOfRegClasses()),
47 // **TODO: use an actual reserved color list
48 ReservedColorListType *RCL = new ReservedColorListType();
50 // create each RegisterClass and put in RegClassList
51 for( unsigned int rc=0; rc < NumOfRegClasses; rc++)
52 RegClassList.push_back( new RegClass(M, MRI.getMachineRegClass(rc), RCL) );
55 //----------------------------------------------------------------------------
56 // This method initally creates interference graphs (one in each reg class)
57 // and IGNodeList (one in each IG). The actual nodes will be pushed later.
58 //----------------------------------------------------------------------------
60 void PhyRegAlloc::createIGNodeListsAndIGs()
62 if(DEBUG_RA ) cout << "Creating LR lists ..." << endl;
65 LiveRangeMapType::const_iterator HMI = (LRI.getLiveRangeMap())->begin();
68 LiveRangeMapType::const_iterator HMIEnd = (LRI.getLiveRangeMap())->end();
70 for( ; HMI != HMIEnd ; ++HMI ) {
74 LiveRange *L = (*HMI).second; // get the LiveRange
78 cout << "\n*?!?Warning: Null liver range found for: ";
79 printValue( (*HMI).first) ; cout << endl;
83 // if the Value * is not null, and LR
84 // is not yet written to the IGNodeList
85 if( !(L->getUserIGNode()) ) {
87 RegClass *const RC = // RegClass of first value in the LR
88 //RegClassList [MRI.getRegClassIDOfValue(*(L->begin()))];
89 RegClassList[ L->getRegClass()->getID() ];
91 RC-> addLRToIG( L ); // add this LR to an IG
97 for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
98 RegClassList[ rc ]->createInterferenceGraph();
101 cout << "LRLists Created!" << endl;
106 //----------------------------------------------------------------------------
107 // This method will add all interferences at for a given instruction.
108 // Interence occurs only if the LR of Def (Inst or Arg) is of the same reg
109 // class as that of live var. The live var passed to this function is the
110 // LVset AFTER the instruction
111 //----------------------------------------------------------------------------
113 void PhyRegAlloc::addInterference(const Value *const Def,
114 const LiveVarSet *const LVSet,
115 const bool isCallInst) {
117 LiveVarSet::const_iterator LIt = LVSet->begin();
119 // get the live range of instruction
120 const LiveRange *const LROfDef = LRI.getLiveRangeForValue( Def );
122 IGNode *const IGNodeOfDef = LROfDef->getUserIGNode();
123 assert( IGNodeOfDef );
125 RegClass *const RCOfDef = LROfDef->getRegClass();
127 // for each live var in live variable set
128 for( ; LIt != LVSet->end(); ++LIt) {
131 cout << "< Def="; printValue(Def);
132 cout << ", Lvar="; printValue( *LIt); cout << "> ";
135 // get the live range corresponding to live var
136 LiveRange *const LROfVar = LRI.getLiveRangeForValue(*LIt );
138 // LROfVar can be null if it is a const since a const
139 // doesn't have a dominating def - see Assumptions above
142 if(LROfDef == LROfVar) // do not set interf for same LR
145 // if 2 reg classes are the same set interference
146 if( RCOfDef == LROfVar->getRegClass() ){
147 RCOfDef->setInterference( LROfDef, LROfVar);
151 else if(DEBUG_RA > 1) {
152 // we will not have LRs for values not explicitly allocated in the
153 // instruction stream (e.g., constants)
154 cout << " warning: no live range for " ;
155 printValue( *LIt); cout << endl; }
164 //----------------------------------------------------------------------------
165 // For a call instruction, this method sets the CallInterference flag in
166 // the LR of each variable live int the Live Variable Set live after the
167 // call instruction (except the return value of the call instruction - since
168 // the return value does not interfere with that call itself).
169 //----------------------------------------------------------------------------
171 void PhyRegAlloc::setCallInterferences(const MachineInstr *MInst,
172 const LiveVarSet *const LVSetAft )
174 // Now find the LR of the return value of the call
177 // We do this because, we look at the LV set *after* the instruction
178 // to determine, which LRs must be saved across calls. The return value
179 // of the call is live in this set - but it does not interfere with call
180 // (i.e., we can allocate a volatile register to the return value)
182 LiveRange *RetValLR = NULL;
184 const Value *RetVal = MRI.getCallInstRetVal( MInst );
187 RetValLR = LRI.getLiveRangeForValue( RetVal );
188 assert( RetValLR && "No LR for RetValue of call");
192 cout << "\n For call inst: " << *MInst;
194 LiveVarSet::const_iterator LIt = LVSetAft->begin();
196 // for each live var in live variable set after machine inst
197 for( ; LIt != LVSetAft->end(); ++LIt) {
199 // get the live range corresponding to live var
200 LiveRange *const LR = LRI.getLiveRangeForValue(*LIt );
202 if( LR && DEBUG_RA) {
203 cout << "\n\tLR Aft Call: ";
208 // LR can be null if it is a const since a const
209 // doesn't have a dominating def - see Assumptions above
210 if( LR && (LR != RetValLR) ) {
211 LR->setCallInterference();
213 cout << "\n ++Added call interf for LR: " ;
223 //----------------------------------------------------------------------------
224 // This method will walk thru code and create interferences in the IG of
226 //----------------------------------------------------------------------------
228 void PhyRegAlloc::buildInterferenceGraphs()
231 if(DEBUG_RA) cout << "Creating interference graphs ..." << endl;
233 Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
235 for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
237 // get the iterator for machine instructions
238 const MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
239 MachineCodeForBasicBlock::const_iterator
240 MInstIterator = MIVec.begin();
242 // iterate over all the machine instructions in BB
243 for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
245 const MachineInstr * MInst = *MInstIterator;
247 // get the LV set after the instruction
248 const LiveVarSet *const LVSetAI =
249 LVI->getLiveVarSetAfterMInst(MInst, *BBI);
251 const bool isCallInst = TM.getInstrInfo().isCall(MInst->getOpCode());
254 //cout << "\nFor call inst: " << *MInst;
256 // set the isCallInterference flag of each live range wich extends
257 // accross this call instruction. This information is used by graph
258 // coloring algo to avoid allocating volatile colors to live ranges
259 // that span across calls (since they have to be saved/restored)
260 setCallInterferences( MInst, LVSetAI);
264 // iterate over MI operands to find defs
265 for( MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done(); ++OpI) {
268 // create a new LR iff this operand is a def
269 addInterference(*OpI, LVSetAI, isCallInst );
273 } // for all operands
276 // Also add interference for any implicit definitions in a machine
277 // instr (currently, only calls have this).
279 unsigned NumOfImpRefs = MInst->getNumImplicitRefs();
280 if( NumOfImpRefs > 0 ) {
281 for(unsigned z=0; z < NumOfImpRefs; z++)
282 if( MInst->implicitRefIsDefined(z) )
283 addInterference( MInst->getImplicitRef(z), LVSetAI, isCallInst );
287 // record phi instrns in PhiInstList
288 if( TM.getInstrInfo().isDummyPhiInstr(MInst->getOpCode()) )
289 PhiInstList.push_back( MInst );
292 } // for all machine instructions in BB
294 } // for all BBs in method
297 // add interferences for method arguments. Since there are no explict
298 // defs in method for args, we have to add them manually
300 addInterferencesForArgs(); // add interference for method args
303 cout << "Interference graphs calculted!" << endl;
310 //----------------------------------------------------------------------------
311 // This method will add interferences for incoming arguments to a method.
312 //----------------------------------------------------------------------------
313 void PhyRegAlloc::addInterferencesForArgs()
315 // get the InSet of root BB
316 const LiveVarSet *const InSet = LVI->getInSetOfBB( Meth->front() );
318 // get the argument list
319 const Method::ArgumentListType& ArgList = Meth->getArgumentList();
321 // get an iterator to arg list
322 Method::ArgumentListType::const_iterator ArgIt = ArgList.begin();
325 for( ; ArgIt != ArgList.end() ; ++ArgIt) { // for each argument
326 addInterference( *ArgIt, InSet, false ); // add interferences between
327 // args and LVars at start
329 cout << " - %% adding interference for argument ";
330 printValue( (const Value *) *ArgIt); cout << endl;
336 //----------------------------------------------------------------------------
337 // This method is called after register allocation is complete to set the
338 // allocated reisters in the machine code. This code will add register numbers
339 // to MachineOperands that contain a Value.
340 //----------------------------------------------------------------------------
342 void PhyRegAlloc::updateMachineCode()
345 Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
347 for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
349 // get the iterator for machine instructions
350 MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
351 MachineCodeForBasicBlock::iterator MInstIterator = MIVec.begin();
353 // iterate over all the machine instructions in BB
354 for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
356 MachineInstr *MInst = *MInstIterator;
358 // if this machine instr is call, insert caller saving code
360 if( (TM.getInstrInfo()).isCall( MInst->getOpCode()) )
361 MRI.insertCallerSavingCode(MInst, *BBI, *this );
363 // If there are instructions to be added, *before* this machine
364 // instruction, add them now.
366 if( AddedInstrMap[ MInst ] ) {
368 deque<MachineInstr *> &IBef = (AddedInstrMap[MInst])->InstrnsBefore;
370 if( ! IBef.empty() ) {
372 deque<MachineInstr *>::iterator AdIt;
374 for( AdIt = IBef.begin(); AdIt != IBef.end() ; ++AdIt ) {
377 cerr << " *$* PREPENDed instr " << *AdIt << endl;
379 MInstIterator = MIVec.insert( MInstIterator, *AdIt );
387 // reset the stack offset for temporary variables since we may
388 // need that to spill
389 mcInfo.popAllTempValues(TM);
391 //for(MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done();++OpI) {
393 for(unsigned OpNum=0; OpNum < MInst->getNumOperands(); ++OpNum) {
395 MachineOperand& Op = MInst->getOperand(OpNum);
397 if( Op.getOperandType() == MachineOperand::MO_VirtualRegister ||
398 Op.getOperandType() == MachineOperand::MO_CCRegister) {
400 const Value *const Val = Op.getVRegValue();
402 // delete this condition checking later (must assert if Val is null)
405 cout << "Warning: NULL Value found for operand" << endl;
408 assert( Val && "Value is NULL");
410 LiveRange *const LR = LRI.getLiveRangeForValue(Val);
414 // nothing to worry if it's a const or a label
417 cout << "*NO LR for operand : " << Op ;
418 cout << " [reg:" << Op.getAllocatedRegNum() << "]";
419 cout << " in inst:\t" << *MInst << endl;
422 // if register is not allocated, mark register as invalid
423 if( Op.getAllocatedRegNum() == -1)
424 Op.setRegForValue( MRI.getInvalidRegNum());
430 unsigned RCID = (LR->getRegClass())->getID();
432 if( LR->hasColor() ) {
433 Op.setRegForValue( MRI.getUnifiedRegNum(RCID, LR->getColor()) );
437 // LR did NOT receive a color (register). Now, insert spill code
438 // for spilled opeands in this machine instruction
440 //assert(0 && "LR must be spilled");
441 insertCode4SpilledLR(LR, MInst, *BBI, OpNum );
446 } // for each operand
449 // If there are instructions to be added *after* this machine
450 // instruction, add them now
452 if( AddedInstrMap[ MInst ] &&
453 ! (AddedInstrMap[ MInst ]->InstrnsAfter).empty() ) {
455 // if there are delay slots for this instruction, the instructions
456 // added after it must really go after the delayed instruction(s)
457 // So, we move the InstrAfter of the current instruction to the
458 // corresponding delayed instruction
461 if((delay=TM.getInstrInfo().getNumDelaySlots(MInst->getOpCode())) >0){
462 move2DelayedInstr(MInst, *(MInstIterator+delay) );
464 if(DEBUG_RA) cout<< "\nMoved an added instr after the delay slot";
470 // Here we can add the "instructions after" to the current
471 // instruction since there are no delay slots for this instruction
473 deque<MachineInstr *> &IAft = (AddedInstrMap[MInst])->InstrnsAfter;
475 if( ! IAft.empty() ) {
477 deque<MachineInstr *>::iterator AdIt;
479 ++MInstIterator; // advance to the next instruction
481 for( AdIt = IAft.begin(); AdIt != IAft.end() ; ++AdIt ) {
484 cerr << " *#* APPENDed instr opcode: " << *AdIt << endl;
486 MInstIterator = MIVec.insert( MInstIterator, *AdIt );
490 // MInsterator already points to the next instr. Since the
491 // for loop also increments it, decrement it to point to the
492 // instruction added last
501 } // for each machine instruction
507 //----------------------------------------------------------------------------
508 // This method inserts spill code for AN operand whose LR was spilled.
509 // This method may be called several times for a single machine instruction
510 // if it contains many spilled operands. Each time it is called, it finds
511 // a register which is not live at that instruction and also which is not
512 // used by other spilled operands of the same instruction. Then it uses
513 // this register temporarily to accomodate the spilled value.
514 //----------------------------------------------------------------------------
515 void PhyRegAlloc::insertCode4SpilledLR(const LiveRange *LR,
517 const BasicBlock *BB,
518 const unsigned OpNum) {
520 MachineOperand& Op = MInst->getOperand(OpNum);
521 bool isDef = MInst->operandIsDefined(OpNum);
522 unsigned RegType = MRI.getRegType( LR );
523 int SpillOff = LR->getSpillOffFromFP();
524 RegClass *RC = LR->getRegClass();
525 const LiveVarSet *LVSetBef = LVI->getLiveVarSetBeforeMInst(MInst, BB);
527 mcInfo.pushTempValue(TM, TM.findOptimalStorageSize(LR->getType()));
529 MachineInstr *MIBef=NULL, *AdIMid=NULL, *MIAft=NULL;
532 TmpReg = getUsableRegAtMI(RC, RegType, MInst,LVSetBef, MIBef, MIAft);
533 TmpReg = MRI.getUnifiedRegNum( RC->getID(), TmpReg );
536 // get the added instructions for this instruciton
537 AddedInstrns *AI = AddedInstrMap[ MInst ];
539 AI = new AddedInstrns();
540 AddedInstrMap[ MInst ] = AI;
547 // for a USE, we have to load the value of LR from stack to a TmpReg
548 // and use the TmpReg as one operand of instruction
550 // actual loading instruction
551 AdIMid = MRI.cpMem2RegMI(MRI.getFramePointer(), SpillOff, TmpReg, RegType);
554 (AI->InstrnsBefore).push_back(MIBef);
556 (AI->InstrnsBefore).push_back(AdIMid);
559 (AI->InstrnsAfter).push_front(MIAft);
563 else { // if this is a Def
565 // for a DEF, we have to store the value produced by this instruction
566 // on the stack position allocated for this LR
568 // actual storing instruction
569 AdIMid = MRI.cpReg2MemMI(TmpReg, MRI.getFramePointer(), SpillOff, RegType);
572 (AI->InstrnsBefore).push_back(MIBef);
574 (AI->InstrnsBefore).push_back(AdIMid);
577 (AI->InstrnsAfter).push_front(MIAft);
581 cerr << "\nFor Inst " << *MInst;
582 cerr << "\n - SPILLED LR:"; LR->printSet();
583 cerr << "\n - Added Instructions:";
584 if( MIBef ) cerr << *MIBef;
586 if( MIAft ) cerr << *MIAft;
588 Op.setRegForValue( TmpReg ); // set the opearnd
598 //----------------------------------------------------------------------------
599 // We can use the following method to get a temporary register to be used
600 // BEFORE any given machine instruction. If there is a register available,
601 // this method will simply return that register and set MIBef = MIAft = NULL.
602 // Otherwise, it will return a register and MIAft and MIBef will contain
603 // two instructions used to free up this returned register.
604 // Returned register number is the UNIFIED register number
605 //----------------------------------------------------------------------------
607 int PhyRegAlloc::getUsableRegAtMI(RegClass *RC,
609 const MachineInstr *MInst,
610 const LiveVarSet *LVSetBef,
612 MachineInstr *MIAft) {
614 int Reg = getUnusedRegAtMI(RC, MInst, LVSetBef);
615 Reg = MRI.getUnifiedRegNum(RC->getID(), Reg);
618 // we found an unused register, so we can simply used
619 MIBef = MIAft = NULL;
622 // we couldn't find an unused register. Generate code to free up a reg by
623 // saving it on stack and restoring after the instruction
625 /**** NOTE: THIS SHOULD USE THE RIGHT SIZE FOR THE REG BEING PUSHED ****/
626 int TmpOff = mcInfo.pushTempValue(TM, /*size*/ 8);
628 Reg = getRegNotUsedByThisInst(RC, MInst);
629 MIBef = MRI.cpReg2MemMI(Reg, MRI.getFramePointer(), TmpOff, RegType );
630 MIAft = MRI.cpMem2RegMI(MRI.getFramePointer(), TmpOff, Reg, RegType );
636 //----------------------------------------------------------------------------
637 // This method is called to get a new unused register that can be used to
638 // accomodate a spilled value.
639 // This method may be called several times for a single machine instruction
640 // if it contains many spilled operands. Each time it is called, it finds
641 // a register which is not live at that instruction and also which is not
642 // used by other spilled operands of the same instruction.
643 // Return register number is relative to the register class. NOT
645 //----------------------------------------------------------------------------
646 int PhyRegAlloc::getUnusedRegAtMI(RegClass *RC,
647 const MachineInstr *MInst,
648 const LiveVarSet *LVSetBef) {
650 unsigned NumAvailRegs = RC->getNumOfAvailRegs();
652 bool *IsColorUsedArr = RC->getIsColorUsedArr();
654 for(unsigned i=0; i < NumAvailRegs; i++)
655 IsColorUsedArr[i] = false;
657 LiveVarSet::const_iterator LIt = LVSetBef->begin();
659 // for each live var in live variable set after machine inst
660 for( ; LIt != LVSetBef->end(); ++LIt) {
662 // get the live range corresponding to live var
663 LiveRange *const LRofLV = LRI.getLiveRangeForValue(*LIt );
665 // LR can be null if it is a const since a const
666 // doesn't have a dominating def - see Assumptions above
668 if( LRofLV->hasColor() )
669 IsColorUsedArr[ LRofLV->getColor() ] = true;
672 // It is possible that one operand of this MInst was already spilled
673 // and it received some register temporarily. If that's the case,
674 // it is recorded in machine operand. We must skip such registers.
676 setRegsUsedByThisInst(RC, MInst);
678 unsigned c; // find first unused color
679 for( c=0; c < NumAvailRegs; c++)
680 if( ! IsColorUsedArr[ c ] ) break;
692 //----------------------------------------------------------------------------
693 // This method modifies the IsColorUsedArr of the register class passed to it.
694 // It sets the bits corresponding to the registers used by this machine
695 // instructions. Explicit operands are set.
696 //----------------------------------------------------------------------------
697 void PhyRegAlloc::setRegsUsedByThisInst(RegClass *RC,
698 const MachineInstr *MInst ) {
700 bool *IsColorUsedArr = RC->getIsColorUsedArr();
702 for(unsigned OpNum=0; OpNum < MInst->getNumOperands(); ++OpNum) {
704 const MachineOperand& Op = MInst->getOperand(OpNum);
706 if( Op.getOperandType() == MachineOperand::MO_VirtualRegister ||
707 Op.getOperandType() == MachineOperand::MO_CCRegister) {
709 const Value *const Val = Op.getVRegValue();
712 if( MRI.getRegClassIDOfValue( Val )== RC->getID() ) {
714 if( (Reg=Op.getAllocatedRegNum()) != -1)
715 IsColorUsedArr[ Reg ] = true;
721 // If there are implicit references, mark them as well
723 for(unsigned z=0; z < MInst->getNumImplicitRefs(); z++) {
725 LiveRange *const LRofImpRef =
726 LRI.getLiveRangeForValue( MInst->getImplicitRef(z) );
729 if( LRofImpRef->hasColor() )
730 IsColorUsedArr[ LRofImpRef->getColor() ] = true;
739 //----------------------------------------------------------------------------
740 // Get any other register in a register class, other than what is used
741 // by operands of a machine instruction.
742 //----------------------------------------------------------------------------
743 int PhyRegAlloc::getRegNotUsedByThisInst(RegClass *RC,
744 const MachineInstr *MInst) {
746 bool *IsColorUsedArr = RC->getIsColorUsedArr();
747 unsigned NumAvailRegs = RC->getNumOfAvailRegs();
750 for(unsigned i=0; i < NumAvailRegs ; i++)
751 IsColorUsedArr[i] = false;
753 setRegsUsedByThisInst(RC, MInst);
755 unsigned c; // find first unused color
756 for( c=0; c < RC->getNumOfAvailRegs(); c++)
757 if( ! IsColorUsedArr[ c ] ) break;
762 assert( 0 && "FATAL: No free register could be found in reg class!!");
770 //----------------------------------------------------------------------------
771 // If there are delay slots for an instruction, the instructions
772 // added after it must really go after the delayed instruction(s).
773 // So, we move the InstrAfter of that instruction to the
774 // corresponding delayed instruction using the following method.
776 //----------------------------------------------------------------------------
777 void PhyRegAlloc:: move2DelayedInstr(const MachineInstr *OrigMI,
778 const MachineInstr *DelayedMI) {
781 // "added after" instructions of the original instr
782 deque<MachineInstr *> &OrigAft = (AddedInstrMap[OrigMI])->InstrnsAfter;
784 // "added instructions" of the delayed instr
785 AddedInstrns *DelayAdI = AddedInstrMap[DelayedMI];
787 if(! DelayAdI ) { // create a new "added after" if necessary
788 DelayAdI = new AddedInstrns();
789 AddedInstrMap[DelayedMI] = DelayAdI;
792 // "added after" instructions of the delayed instr
793 deque<MachineInstr *> &DelayedAft = DelayAdI->InstrnsAfter;
795 // go thru all the "added after instructions" of the original instruction
796 // and append them to the "addded after instructions" of the delayed
799 deque<MachineInstr *>::iterator OrigAdIt;
801 for( OrigAdIt = OrigAft.begin(); OrigAdIt != OrigAft.end() ; ++OrigAdIt ) {
802 DelayedAft.push_back( *OrigAdIt );
805 // empty the "added after instructions" of the original instruction
810 //----------------------------------------------------------------------------
811 // This method prints the code with registers after register allocation is
813 //----------------------------------------------------------------------------
814 void PhyRegAlloc::printMachineCode()
817 cout << endl << ";************** Method ";
818 cout << Meth->getName() << " *****************" << endl;
820 Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
822 for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
824 cout << endl ; printLabel( *BBI); cout << ": ";
826 // get the iterator for machine instructions
827 MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
828 MachineCodeForBasicBlock::iterator MInstIterator = MIVec.begin();
830 // iterate over all the machine instructions in BB
831 for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
833 MachineInstr *const MInst = *MInstIterator;
836 cout << endl << "\t";
837 cout << TargetInstrDescriptors[MInst->getOpCode()].opCodeString;
840 //for(MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done();++OpI) {
842 for(unsigned OpNum=0; OpNum < MInst->getNumOperands(); ++OpNum) {
844 MachineOperand& Op = MInst->getOperand(OpNum);
846 if( Op.getOperandType() == MachineOperand::MO_VirtualRegister ||
847 Op.getOperandType() == MachineOperand::MO_CCRegister /*||
848 Op.getOperandType() == MachineOperand::MO_PCRelativeDisp*/ ) {
850 const Value *const Val = Op.getVRegValue () ;
851 // ****this code is temporary till NULL Values are fixed
853 cout << "\t<*NULL*>";
857 // if a label or a constant
858 if( (Val->getValueType() == Value::BasicBlockVal) ) {
860 cout << "\t"; printLabel( Op.getVRegValue () );
863 // else it must be a register value
864 const int RegNum = Op.getAllocatedRegNum();
866 cout << "\t" << "%" << MRI.getUnifiedRegName( RegNum );
870 else if(Op.getOperandType() == MachineOperand::MO_MachineRegister) {
871 cout << "\t" << "%" << MRI.getUnifiedRegName(Op.getMachineRegNum());
875 cout << "\t" << Op; // use dump field
880 unsigned NumOfImpRefs = MInst->getNumImplicitRefs();
881 if( NumOfImpRefs > 0 ) {
883 cout << "\tImplicit:";
885 for(unsigned z=0; z < NumOfImpRefs; z++) {
886 printValue( MInst->getImplicitRef(z) );
892 } // for all machine instructions
903 //----------------------------------------------------------------------------
905 //----------------------------------------------------------------------------
907 void PhyRegAlloc::colorCallRetArgs()
910 CallRetInstrListType &CallRetInstList = LRI.getCallRetInstrList();
911 CallRetInstrListType::const_iterator It = CallRetInstList.begin();
913 for( ; It != CallRetInstList.end(); ++It ) {
915 const MachineInstr *const CRMI = *It;
916 unsigned OpCode = CRMI->getOpCode();
918 // get the added instructions for this Call/Ret instruciton
919 AddedInstrns *AI = AddedInstrMap[ CRMI ];
921 AI = new AddedInstrns();
922 AddedInstrMap[ CRMI ] = AI;
925 // Tmp stack poistions are needed by some calls that have spilled args
926 // So reset it before we call each such method
927 mcInfo.popAllTempValues(TM);
929 if( (TM.getInstrInfo()).isCall( OpCode ) )
930 MRI.colorCallArgs( CRMI, LRI, AI, *this );
932 else if ( (TM.getInstrInfo()).isReturn(OpCode) )
933 MRI.colorRetValue( CRMI, LRI, AI );
935 else assert( 0 && "Non Call/Ret instrn in CallRetInstrList\n" );
943 //----------------------------------------------------------------------------
945 //----------------------------------------------------------------------------
946 void PhyRegAlloc::colorIncomingArgs()
948 const BasicBlock *const FirstBB = Meth->front();
949 const MachineInstr *FirstMI = *((FirstBB->getMachineInstrVec()).begin());
950 assert( FirstMI && "No machine instruction in entry BB");
952 AddedInstrns *AI = AddedInstrMap[ FirstMI ];
954 AI = new AddedInstrns();
955 AddedInstrMap[ FirstMI ] = AI;
958 MRI.colorMethodArgs(Meth, LRI, AI );
962 //----------------------------------------------------------------------------
963 // Used to generate a label for a basic block
964 //----------------------------------------------------------------------------
965 void PhyRegAlloc::printLabel(const Value *const Val)
968 cout << Val->getName();
970 cout << "Label" << Val;
974 //----------------------------------------------------------------------------
975 // This method calls setSugColorUsable method of each live range. This
976 // will determine whether the suggested color of LR is really usable.
977 // A suggested color is not usable when the suggested color is volatile
978 // AND when there are call interferences
979 //----------------------------------------------------------------------------
981 void PhyRegAlloc::markUnusableSugColors()
983 if(DEBUG_RA ) cout << "\nmarking unusable suggested colors ..." << endl;
986 LiveRangeMapType::const_iterator HMI = (LRI.getLiveRangeMap())->begin();
987 LiveRangeMapType::const_iterator HMIEnd = (LRI.getLiveRangeMap())->end();
989 for( ; HMI != HMIEnd ; ++HMI ) {
993 LiveRange *L = (*HMI).second; // get the LiveRange
996 if( L->hasSuggestedColor() ) {
998 int RCID = (L->getRegClass())->getID();
999 if( MRI.isRegVolatile( RCID, L->getSuggestedColor()) &&
1000 L->isCallInterference() )
1001 L->setSuggestedColorUsable( false );
1003 L->setSuggestedColorUsable( true );
1005 } // if L->hasSuggestedColor()
1007 } // for all LR's in hash map
1012 //----------------------------------------------------------------------------
1013 // The following method will set the stack offsets of the live ranges that
1014 // are decided to be spillled. This must be called just after coloring the
1015 // LRs using the graph coloring algo. For each live range that is spilled,
1016 // this method allocate a new spill position on the stack.
1017 //----------------------------------------------------------------------------
1019 void PhyRegAlloc::allocateStackSpace4SpilledLRs()
1021 if(DEBUG_RA ) cout << "\nsetting LR stack offsets ..." << endl;
1023 // hash map iterator
1024 LiveRangeMapType::const_iterator HMI = (LRI.getLiveRangeMap())->begin();
1025 LiveRangeMapType::const_iterator HMIEnd = (LRI.getLiveRangeMap())->end();
1027 for( ; HMI != HMIEnd ; ++HMI ) {
1028 if( (*HMI).first ) {
1029 LiveRange *L = (*HMI).second; // get the LiveRange
1031 if( ! L->hasColor() )
1032 L->setSpillOffFromFP(mcInfo.allocateSpilledValue(TM,L->getType()));
1034 } // for all LR's in hash map
1039 //----------------------------------------------------------------------------
1040 // The entry pont to Register Allocation
1041 //----------------------------------------------------------------------------
1043 void PhyRegAlloc::allocateRegisters()
1046 // make sure that we put all register classes into the RegClassList
1047 // before we call constructLiveRanges (now done in the constructor of
1048 // PhyRegAlloc class).
1050 constructLiveRanges(); // create LR info
1053 LRI.printLiveRanges();
1055 createIGNodeListsAndIGs(); // create IGNode list and IGs
1057 buildInterferenceGraphs(); // build IGs in all reg classes
1061 // print all LRs in all reg classes
1062 for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
1063 RegClassList[ rc ]->printIGNodeList();
1065 // print IGs in all register classes
1066 for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
1067 RegClassList[ rc ]->printIG();
1070 LRI.coalesceLRs(); // coalesce all live ranges
1072 // coalscing could not get rid of all phi's, add phi elimination
1074 // insertPhiEleminateInstrns();
1077 // print all LRs in all reg classes
1078 for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
1079 RegClassList[ rc ]->printIGNodeList();
1081 // print IGs in all register classes
1082 for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
1083 RegClassList[ rc ]->printIG();
1087 // mark un-usable suggested color before graph coloring algorithm.
1088 // When this is done, the graph coloring algo will not reserve
1089 // suggested color unnecessarily - they can be used by another LR
1090 markUnusableSugColors();
1092 // color all register classes using the graph coloring algo
1093 for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
1094 RegClassList[ rc ]->colorAllRegs();
1096 // Atter grpah coloring, if some LRs did not receive a color (i.e, spilled)
1097 // a poistion for such spilled LRs
1098 allocateStackSpace4SpilledLRs();
1100 // color incoming args and call args
1101 colorIncomingArgs();
1105 updateMachineCode();
1107 MachineCodeForMethod::get(Meth).dump();
1108 printMachineCode(); // only for DEBUGGING