+//===-- LiveRangeInfo.cpp -------------------------------------------------===//
+//
+// Live range construction for coloring-based register allocation for LLVM.
+//
+//===----------------------------------------------------------------------===//
+
#include "llvm/CodeGen/LiveRangeInfo.h"
-#include "llvm/CodeGen/RegClass.h"
+#include "RegAllocCommon.h"
+#include "RegClass.h"
+#include "llvm/CodeGen/IGNode.h"
#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Method.h"
-#include <iostream>
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Function.h"
+#include "Support/SetOperations.h"
using std::cerr;
-//---------------------------------------------------------------------------
-// Constructor
-//---------------------------------------------------------------------------
-LiveRangeInfo::LiveRangeInfo(const Method *const M,
- const TargetMachine& tm,
+unsigned LiveRange::getRegClassID() const { return getRegClass()->getID(); }
+
+LiveRangeInfo::LiveRangeInfo(const Function *F, const TargetMachine &tm,
std::vector<RegClass *> &RCL)
- : Meth(M), LiveRangeMap(), TM(tm),
- RegClassList(RCL), MRI(tm.getRegInfo())
-{ }
+ : Meth(F), TM(tm), RegClassList(RCL), MRI(tm.getRegInfo()) { }
-//---------------------------------------------------------------------------
-// Destructor: Deletes all LiveRanges in the LiveRangeMap
-//---------------------------------------------------------------------------
LiveRangeInfo::~LiveRangeInfo() {
- LiveRangeMapType::iterator MI = LiveRangeMap.begin();
+ for (LiveRangeMapType::iterator MI = LiveRangeMap.begin();
+ MI != LiveRangeMap.end(); ++MI) {
- for( ; MI != LiveRangeMap.end() ; ++MI) {
if (MI->first && MI->second) {
LiveRange *LR = MI->second;
// live range. We have to make the other entries NULL when we delete
// a live range.
- LiveRange::iterator LI = LR->begin();
-
- for( ; LI != LR->end() ; ++LI)
+ for (LiveRange::iterator LI = LR->begin(); LI != LR->end(); ++LI)
LiveRangeMap[*LI] = 0;
delete LR;
// Note: the caller must make sure that L1 and L2 are distinct and both
// LRs don't have suggested colors
//---------------------------------------------------------------------------
-void LiveRangeInfo::unionAndUpdateLRs(LiveRange *const L1, LiveRange *L2)
-{
- assert( L1 != L2);
- L1->setUnion( L2 ); // add elements of L2 to L1
- ValueSet::iterator L2It;
- for( L2It = L2->begin() ; L2It != L2->end(); ++L2It) {
+void LiveRangeInfo::unionAndUpdateLRs(LiveRange *L1, LiveRange *L2) {
+ assert(L1 != L2 && (!L1->hasSuggestedColor() || !L2->hasSuggestedColor()));
+ set_union(*L1, *L2); // add elements of L2 to L1
+ for(ValueSet::iterator L2It = L2->begin(); L2It != L2->end(); ++L2It) {
//assert(( L1->getTypeID() == L2->getTypeID()) && "Merge:Different types");
- L1->add( *L2It ); // add the var in L2 to L1
- LiveRangeMap[ *L2It ] = L1; // now the elements in L2 should map
+ L1->insert(*L2It); // add the var in L2 to L1
+ LiveRangeMap[*L2It] = L1; // now the elements in L2 should map
//to L1
}
// must have the same color.
if(L2->hasSuggestedColor())
- L1->setSuggestedColor( L2->getSuggestedColor() );
+ L1->setSuggestedColor(L2->getSuggestedColor());
- if( L2->isCallInterference() )
+ if (L2->isCallInterference())
L1->setCallInterference();
-
- L1->addSpillCost( L2->getSpillCost() ); // add the spill costs
-
+ // add the spill costs
+ L1->addSpillCost(L2->getSpillCost());
+
delete L2; // delete L2 as it is no longer needed
}
-
//---------------------------------------------------------------------------
-// Method for constructing all live ranges in a method. It creates live
-// ranges for all values defined in the instruction stream. Also, it
-// creates live ranges for all incoming arguments of the method.
+// Method for creating a single live range for a definition.
+// The definition must be represented by a virtual register (a Value).
+// Note: this function does *not* check that no live range exists for def.
//---------------------------------------------------------------------------
-void LiveRangeInfo::constructLiveRanges()
-{
-
- if( DEBUG_RA)
- cerr << "Consturcting Live Ranges ...\n";
-
- // first find the live ranges for all incoming args of the method since
- // those LRs start from the start of the method
-
- // get the argument list
- const Method::ArgumentListType& ArgList = Meth->getArgumentList();
- // get an iterator to arg list
- Method::ArgumentListType::const_iterator ArgIt = ArgList.begin();
-
-
- for( ; ArgIt != ArgList.end() ; ++ArgIt) { // for each argument
- LiveRange * ArgRange = new LiveRange(); // creates a new LR and
- const Value *const Val = (const Value *) *ArgIt;
-
- assert( Val);
-
- ArgRange->add(Val); // add the arg (def) to it
- LiveRangeMap[Val] = ArgRange;
-
- // create a temp machine op to find the register class of value
- //const MachineOperand Op(MachineOperand::MO_VirtualRegister);
-
- unsigned rcid = MRI.getRegClassIDOfValue( Val );
- ArgRange->setRegClass(RegClassList[ rcid ] );
-
- if( DEBUG_RA > 1) {
- cerr << " adding LiveRange for argument ";
- printValue((const Value *) *ArgIt); cerr << "\n";
- }
+LiveRange*
+LiveRangeInfo::createNewLiveRange(const Value* Def, bool isCC /* = false*/)
+{
+ LiveRange* DefRange = new LiveRange(); // Create a new live range,
+ DefRange->insert(Def); // add Def to it,
+ LiveRangeMap[Def] = DefRange; // and update the map.
+
+ // set the register class of the new live range
+ DefRange->setRegClass(RegClassList[MRI.getRegClassIDOfType(Def->getType(),
+ isCC)]);
+
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges) {
+ cerr << " Creating a LR for def ";
+ if (isCC) cerr << " (CC Register!)";
+ cerr << " : " << RAV(Def) << "\n";
}
+ return DefRange;
+}
- // Now suggest hardware registers for these method args
- MRI.suggestRegs4MethodArgs(Meth, *this);
+LiveRange*
+LiveRangeInfo::createOrAddToLiveRange(const Value* Def, bool isCC /* = false*/)
+{
+ LiveRange *DefRange = LiveRangeMap[Def];
+
+ // check if the LR is already there (because of multiple defs)
+ if (!DefRange) {
+ DefRange = createNewLiveRange(Def, isCC);
+ } else { // live range already exists
+ DefRange->insert(Def); // add the operand to the range
+ LiveRangeMap[Def] = DefRange; // make operand point to merged set
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges)
+ cerr << " Added to existing LR for def: " << RAV(Def) << "\n";
+ }
+ return DefRange;
+}
- // Now find speical LLVM instructions (CALL, RET) and LRs in machine
- // instructions.
+//---------------------------------------------------------------------------
+// Method for constructing all live ranges in a function. It creates live
+// ranges for all values defined in the instruction stream. Also, it
+// creates live ranges for all incoming arguments of the function.
+//---------------------------------------------------------------------------
+void LiveRangeInfo::constructLiveRanges() {
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges)
+ cerr << "Constructing Live Ranges ...\n";
- Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
- for( ; BBI != Meth->end(); ++BBI) { // go thru BBs in random order
+ // first find the live ranges for all incoming args of the function since
+ // those LRs start from the start of the function
+ for (Function::const_aiterator AI = Meth->abegin(); AI != Meth->aend(); ++AI)
+ createNewLiveRange(AI, /*isCC*/ false);
- // Now find all LRs for machine the instructions. A new LR will be created
- // only for defs in the machine instr since, we assume that all Values are
- // defined before they are used. However, there can be multiple defs for
- // the same Value in machine instructions.
+ // Now suggest hardware registers for these function args
+ MRI.suggestRegs4MethodArgs(Meth, *this);
- // get the iterator for machine instructions
- const MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
- MachineCodeForBasicBlock::const_iterator MInstIterator = MIVec.begin();
+ // Now create LRs for machine instructions. A new LR will be created
+ // only for defs in the machine instr since, we assume that all Values are
+ // defined before they are used. However, there can be multiple defs for
+ // the same Value in machine instructions.
+ //
+ // Also, find CALL and RETURN instructions, which need extra work.
+ //
+ MachineFunction &MF = MachineFunction::get(Meth);
+ for (MachineFunction::iterator BBI = MF.begin(); BBI != MF.end(); ++BBI) {
+ MachineBasicBlock &MBB = *BBI;
// iterate over all the machine instructions in BB
- for( ; MInstIterator != MIVec.end(); MInstIterator++) {
-
- const MachineInstr * MInst = *MInstIterator;
-
- // Now if the machine instruction is a call/return instruction,
- // add it to CallRetInstrList for processing its implicit operands
+ for(MachineBasicBlock::iterator MInstIterator = MBB.begin();
+ MInstIterator != MBB.end(); ++MInstIterator) {
+ MachineInstr *MInst = *MInstIterator;
+ // If the machine instruction is a call/return instruction, add it to
+ // CallRetInstrList for processing its args, ret value, and ret addr.
+ //
if(TM.getInstrInfo().isReturn(MInst->getOpCode()) ||
TM.getInstrInfo().isCall(MInst->getOpCode()))
- CallRetInstrList.push_back( MInst );
+ CallRetInstrList.push_back(MInst);
-
- // iterate over MI operands to find defs
- for (MachineInstr::val_const_op_iterator OpI(MInst); !OpI.done(); ++OpI) {
- if(DEBUG_RA) {
- MachineOperand::MachineOperandType OpTyp =
- OpI.getMachineOperand().getOperandType();
-
- if (OpTyp == MachineOperand::MO_CCRegister) {
- cerr << "\n**CC reg found. Is Def=" << OpI.isDef() << " Val:";
- printValue( OpI.getMachineOperand().getVRegValue() );
- cerr << "\n";
- }
+ // iterate over explicit MI operands and create a new LR
+ // for each operand that is defined by the instruction
+ for (MachineInstr::val_op_iterator OpI = MInst->begin(),
+ OpE = MInst->end(); OpI != OpE; ++OpI)
+ if (OpI.isDefOnly() || OpI.isDefAndUse()) {
+ const Value *Def = *OpI;
+ bool isCC = (OpI.getMachineOperand().getType()
+ == MachineOperand::MO_CCRegister);
+ createOrAddToLiveRange(Def, isCC);
}
- // create a new LR iff this operand is a def
- if( OpI.isDef() ) {
- const Value *const Def = *OpI;
-
- // Only instruction values are accepted for live ranges here
- if( Def->getValueType() != Value::InstructionVal ) {
- cerr << "\n**%%Error: Def is not an instruction val. Def=";
- printValue( Def ); cerr << "\n";
- continue;
- }
-
- LiveRange *DefRange = LiveRangeMap[Def];
-
- // see LR already there (because of multiple defs)
- if( !DefRange) { // if it is not in LiveRangeMap
- DefRange = new LiveRange(); // creates a new live range and
- DefRange->add( Def ); // add the instruction (def) to it
- LiveRangeMap[ Def ] = DefRange; // update the map
-
- if( DEBUG_RA > 1) {
- cerr << " creating a LR for def: ";
- printValue(Def); cerr << "\n";
- }
-
- // set the register class of the new live range
- //assert( RegClassList.size() );
- MachineOperand::MachineOperandType OpTy =
- OpI.getMachineOperand().getOperandType();
-
- bool isCC = ( OpTy == MachineOperand::MO_CCRegister);
- unsigned rcid = MRI.getRegClassIDOfValue(
- OpI.getMachineOperand().getVRegValue(), isCC );
-
-
- if(isCC && DEBUG_RA) {
- cerr << "\a**created a LR for a CC reg:";
- printValue( OpI.getMachineOperand().getVRegValue() );
- }
-
- DefRange->setRegClass( RegClassList[ rcid ] );
-
- }
- else {
- DefRange->add( Def ); // add the opearand to def range
- // update the map - Operand points
- // to the merged set
- LiveRangeMap[ Def ] = DefRange;
-
- if( DEBUG_RA > 1) {
- cerr << " added to an existing LR for def: ";
- printValue( Def ); cerr << "\n";
- }
- }
-
- } // if isDef()
-
- } // for all opereands in machine instructions
+ // iterate over implicit MI operands and create a new LR
+ // for each operand that is defined by the instruction
+ for (unsigned i = 0; i < MInst->getNumImplicitRefs(); ++i)
+ if (MInst->getImplicitOp(i).opIsDefOnly() ||
+ MInst->getImplicitOp(i).opIsDefAndUse()) {
+ const Value *Def = MInst->getImplicitRef(i);
+ createOrAddToLiveRange(Def, /*isCC*/ false);
+ }
} // for all machine instructions in the BB
- } // for all BBs in method
-
+ } // for all BBs in function
// Now we have to suggest clors for call and return arg live ranges.
// Also, if there are implicit defs (e.g., retun value of a call inst)
// they must be added to the live range list
-
+ //
suggestRegs4CallRets();
- if( DEBUG_RA)
+ if( DEBUG_RA >= RA_DEBUG_LiveRanges)
cerr << "Initial Live Ranges constructed!\n";
-
}
//---------------------------------------------------------------------------
// If some live ranges must be colored with specific hardware registers
// (e.g., for outgoing call args), suggesting of colors for such live
-// ranges is done using target specific method. Those methods are called
+// ranges is done using target specific function. Those functions are called
// from this function. The target specific methods must:
// 1) suggest colors for call and return args.
// 2) create new LRs for implicit defs in machine instructions
//---------------------------------------------------------------------------
-void LiveRangeInfo::suggestRegs4CallRets()
-{
-
- CallRetInstrListType::const_iterator It = CallRetInstrList.begin();
-
- for( ; It != CallRetInstrList.end(); ++It ) {
-
- const MachineInstr *MInst = *It;
- MachineOpCode OpCode = MInst->getOpCode();
-
- if( (TM.getInstrInfo()).isReturn(OpCode) )
- MRI.suggestReg4RetValue( MInst, *this);
-
- else if( (TM.getInstrInfo()).isCall( OpCode ) )
- MRI.suggestRegs4CallArgs( MInst, *this, RegClassList );
-
+void LiveRangeInfo::suggestRegs4CallRets() {
+ std::vector<MachineInstr*>::iterator It = CallRetInstrList.begin();
+ for( ; It != CallRetInstrList.end(); ++It) {
+ MachineInstr *MInst = *It;
+ MachineOpCode OpCode = MInst->getOpCode();
+
+ if ((TM.getInstrInfo()).isReturn(OpCode))
+ MRI.suggestReg4RetValue(MInst, *this);
+ else if ((TM.getInstrInfo()).isCall(OpCode))
+ MRI.suggestRegs4CallArgs(MInst, *this);
else
- assert( 0 && "Non call/ret instr in CallRetInstrList" );
+ assert( 0 && "Non call/ret instr in CallRetInstrList" );
}
-
}
/* Algorithm:
- for each BB in method
+ for each BB in function
for each machine instruction (inst)
for each definition (def) in inst
for each operand (op) of inst that is a use
//---------------------------------------------------------------------------
void LiveRangeInfo::coalesceLRs()
{
- if( DEBUG_RA)
- cerr << "\nCoalscing LRs ...\n";
-
- Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
+ if(DEBUG_RA >= RA_DEBUG_LiveRanges)
+ cerr << "\nCoalescing LRs ...\n";
- for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
-
- // get the iterator for machine instructions
- const MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
- MachineCodeForBasicBlock::const_iterator MInstIterator = MIVec.begin();
+ MachineFunction &MF = MachineFunction::get(Meth);
+ for (MachineFunction::iterator BBI = MF.begin(); BBI != MF.end(); ++BBI) {
+ MachineBasicBlock &MBB = *BBI;
// iterate over all the machine instructions in BB
- for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
-
- const MachineInstr * MInst = *MInstIterator;
+ for(MachineBasicBlock::iterator MII = MBB.begin(); MII != MBB.end(); ++MII){
+ const MachineInstr *MI = *MII;
- if( DEBUG_RA > 1) {
+ if( DEBUG_RA >= RA_DEBUG_LiveRanges) {
cerr << " *Iterating over machine instr ";
- MInst->dump();
+ MI->dump();
cerr << "\n";
}
-
// iterate over MI operands to find defs
- for(MachineInstr::val_const_op_iterator DefI(MInst);!DefI.done();++DefI){
-
- if( DefI.isDef() ) { // iff this operand is a def
-
- LiveRange *const LROfDef = getLiveRangeForValue( *DefI );
- assert( LROfDef );
- RegClass *const RCOfDef = LROfDef->getRegClass();
-
- MachineInstr::val_const_op_iterator UseI(MInst);
- for( ; !UseI.done(); ++UseI){ // for all uses
-
- LiveRange *const LROfUse = getLiveRangeForValue( *UseI );
-
- if( ! LROfUse ) { // if LR of use is not found
-
+ for(MachineInstr::const_val_op_iterator DefI = MI->begin(),
+ DefE = MI->end(); DefI != DefE; ++DefI) {
+ if (DefI.isDefOnly() || DefI.isDefAndUse()) { // this operand is modified
+ LiveRange *LROfDef = getLiveRangeForValue( *DefI );
+ RegClass *RCOfDef = LROfDef->getRegClass();
+
+ MachineInstr::const_val_op_iterator UseI = MI->begin(),
+ UseE = MI->end();
+ for( ; UseI != UseE; ++UseI) { // for all uses
+ LiveRange *LROfUse = getLiveRangeForValue( *UseI );
+ if (!LROfUse) { // if LR of use is not found
//don't warn about labels
- if (!((*UseI)->getType())->isLabelType() && DEBUG_RA) {
- cerr<<" !! Warning: No LR for use "; printValue(*UseI);
- cerr << "\n";
- }
+ if (!isa<BasicBlock>(*UseI) && DEBUG_RA >= RA_DEBUG_LiveRanges)
+ cerr << " !! Warning: No LR for use " << RAV(*UseI) << "\n";
continue; // ignore and continue
}
- if( LROfUse == LROfDef) // nothing to merge if they are same
+ if (LROfUse == LROfDef) // nothing to merge if they are same
continue;
- //RegClass *const RCOfUse = LROfUse->getRegClass();
- //if( RCOfDef == RCOfUse ) { // if the reg classes are the same
-
- if( MRI.getRegType(LROfDef) == MRI.getRegType(LROfUse) ) {
-
+ if (MRI.getRegType(LROfDef) == MRI.getRegType(LROfUse)) {
// If the two RegTypes are the same
-
- if( ! RCOfDef->getInterference(LROfDef, LROfUse) ) {
+ if (!RCOfDef->getInterference(LROfDef, LROfUse) ) {
unsigned CombinedDegree =
LROfDef->getUserIGNode()->getNumOfNeighbors() +
LROfUse->getUserIGNode()->getNumOfNeighbors();
- if( CombinedDegree <= RCOfDef->getNumOfAvailRegs() ) {
+ if (CombinedDegree > RCOfDef->getNumOfAvailRegs()) {
+ // get more precise estimate of combined degree
+ CombinedDegree = LROfDef->getUserIGNode()->
+ getCombinedDegree(LROfUse->getUserIGNode());
+ }
+ if (CombinedDegree <= RCOfDef->getNumOfAvailRegs()) {
// if both LRs do not have suggested colors
- if( ! (LROfDef->hasSuggestedColor() &&
- LROfUse->hasSuggestedColor() ) ) {
+ if (!(LROfDef->hasSuggestedColor() &&
+ LROfUse->hasSuggestedColor())) {
RCOfDef->mergeIGNodesOfLRs(LROfDef, LROfUse);
unionAndUpdateLRs(LROfDef, LROfUse);
}
-
} // if combined degree is less than # of regs
-
} // if def and use do not interfere
-
}// if reg classes are the same
-
} // for all uses
-
} // if def
-
} // for all defs
-
} // for all machine instructions
-
} // for all BBs
- if( DEBUG_RA)
- cerr << "\nCoalscing Done!\n";
-
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges)
+ cerr << "\nCoalescing Done!\n";
}
/*--------------------------- Debug code for printing ---------------*/
-void LiveRangeInfo::printLiveRanges()
-{
+void LiveRangeInfo::printLiveRanges() {
LiveRangeMapType::iterator HMI = LiveRangeMap.begin(); // hash map iterator
cerr << "\nPrinting Live Ranges from Hash Map:\n";
- for( ; HMI != LiveRangeMap.end() ; ++HMI) {
- if( HMI->first && HMI->second ) {
- cerr <<" "; printValue((*HMI).first); cerr << "\t: ";
- HMI->second->printSet(); cerr << "\n";
+ for( ; HMI != LiveRangeMap.end(); ++HMI) {
+ if (HMI->first && HMI->second) {
+ cerr << " Value* " << RAV(HMI->first) << "\t: ";
+ if (IGNode* igNode = HMI->second->getUserIGNode())
+ cerr << "LR# " << igNode->getIndex();
+ else
+ cerr << "LR# " << "<no-IGNode>";
+ cerr << "\t:Values = "; printSet(*HMI->second); cerr << "\n";
}
}
}
-
-
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