-#include "llvm/CodeGen/LiveRangeInfo.h"
-
-LiveRangeInfo::LiveRangeInfo(const Method *const M,
- const TargetMachine& tm,
- vector<RegClass *> &RCL)
- : Meth(M), LiveRangeMap(),
- TM(tm), RegClassList(RCL)
-{ }
+//===-- LiveRangeInfo.cpp -------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Live range construction for coloring-based register allocation for LLVM.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IGNode.h"
+#include "LiveRangeInfo.h"
+#include "RegAllocCommon.h"
+#include "RegClass.h"
+#include "llvm/Function.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "../SparcV9RegInfo.h"
+#include "Support/SetOperations.h"
+
+namespace llvm {
+
+unsigned LiveRange::getRegClassID() const { return getRegClass()->getID(); }
+
+LiveRangeInfo::LiveRangeInfo(const Function *F, const TargetMachine &tm,
+ std::vector<RegClass *> &RCL)
+ : Meth(F), TM(tm), RegClassList(RCL), MRI(tm.getRegInfo()) { }
+
+
+LiveRangeInfo::~LiveRangeInfo() {
+ for (LiveRangeMapType::iterator MI = LiveRangeMap.begin();
+ MI != LiveRangeMap.end(); ++MI) {
+
+ if (MI->first && MI->second) {
+ LiveRange *LR = MI->second;
+
+ // we need to be careful in deleting LiveRanges in LiveRangeMap
+ // since two/more Values in the live range map can point to the same
+ // live range. We have to make the other entries NULL when we delete
+ // a live range.
+
+ for (LiveRange::iterator LI = LR->begin(); LI != LR->end(); ++LI)
+ LiveRangeMap[*LI] = 0;
+
+ delete LR;
+ }
+ }
+}
+//---------------------------------------------------------------------------
// union two live ranges into one. The 2nd LR is deleted. Used for coalescing.
-// Note: the caller must make sure that L1 and L2 are distinct
+// 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;
+void LiveRangeInfo::unionAndUpdateLRs(LiveRange *L1, LiveRange *L2) {
+ assert(L1 != L2 && (!L1->hasSuggestedColor() || !L2->hasSuggestedColor()));
+ assert(! (L1->hasColor() && L2->hasColor()) ||
+ L1->getColor() == L2->getColor());
- for( L2It = L2->begin() ; L2It != L2->end(); ++L2It) {
+ 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 to L1
+ L1->insert(*L2It); // add the var in L2 to L1
+ LiveRangeMap[*L2It] = L1; // now the elements in L2 should map
+ //to L1
}
- delete ( L2 ); // delete L2 as it is no longer needed
+
+ // set call interference for L1 from L2
+ if (L2->isCallInterference())
+ L1->setCallInterference();
+
+ // add the spill costs
+ L1->addSpillCost(L2->getSpillCost());
+
+ // If L2 has a color, give L1 that color. Note that L1 may have had the same
+ // color or none, but would not have a different color as asserted above.
+ if (L2->hasColor())
+ L1->setColor(L2->getColor());
+
+ // Similarly, if LROfUse(L2) has a suggested color, the new range
+ // must have the same color.
+ if (L2->hasSuggestedColor())
+ L1->setSuggestedColor(L2->getSuggestedColor());
+
+ delete L2; // delete L2 as it is no longer needed
}
+//---------------------------------------------------------------------------
+// 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()
+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) {
+ std::cerr << " Creating a LR for def ";
+ if (isCC) std::cerr << " (CC Register!)";
+ std::cerr << " : " << RAV(Def) << "\n";
+ }
+ return DefRange;
+}
- if( DEBUG_RA)
- cout << "Consturcting Live Ranges ..." << endl;
-
- // 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);
+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)
+ std::cerr << " Added to existing LR for def: " << RAV(Def) << "\n";
+ }
+ return DefRange;
+}
- 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);
+//---------------------------------------------------------------------------
+// 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() {
- unsigned rcid = (TM.getRegInfo()).getRegClassIDOfValue( Val );
- ArgRange->setRegClass(RegClassList[ rcid ] );
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges)
+ std::cerr << "Constructing Live Ranges ...\n";
-
- if( DEBUG_RA > 1) {
- cout << " adding LiveRange for argument ";
- printValue( (const Value *) *ArgIt); cout << endl;
- }
- }
+ // 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 suggest hardware registers for these function args
+ MRI.suggestRegs4MethodArgs(Meth, *this);
- // Now find all LRs for machine the instructions. A new LR will be created
+ // 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.
-
- Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
-
- for( ; BBI != Meth->end(); ++BBI) { // go thru BBs in random order
-
- // get the iterator for machine instructions
- const MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
- MachineCodeForBasicBlock::const_iterator
- MInstIterator = MIVec.begin();
+ //
+ // 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;
-
- // iterate over MI operands to find defs
- for( MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done(); OpI++) {
-
-
- // delete later from here ************
- MachineOperand::MachineOperandType OpTyp =
- OpI.getMachineOperand().getOperandType();
-
- if ( OpTyp == MachineOperand::MO_CCRegister) {
- cout << "\n**CC reg found. Is Def=" << OpI.isDef() << " Val:";
- printValue( OpI.getMachineOperand().getVRegValue() );
- cout << endl;
+ 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);
+
+ // 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.isDef()) {
+ const Value *Def = *OpI;
+ bool isCC = (OpI.getMachineOperand().getType()
+ == MachineOperand::MO_CCRegister);
+ LiveRange* LR = createOrAddToLiveRange(Def, isCC);
+
+ // If the operand has a pre-assigned register,
+ // set it directly in the LiveRange
+ if (OpI.getMachineOperand().hasAllocatedReg()) {
+ unsigned getClassId;
+ LR->setColor(MRI.getClassRegNum(OpI.getMachineOperand().getReg(),
+ getClassId));
+ }
}
- // ************* to here
-
-
-
- // create a new LR iff this operand is a def
- if( OpI.isDef() ) {
-
- const Value *const Def = *OpI;
- 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) {
- cout << " creating a LR for def: ";
- printValue(Def); cout << endl;
- }
-
- // 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 = (TM.getRegInfo()).getRegClassIDOfValue(
- OpI.getMachineOperand().getVRegValue(), isCC );
-
-
- if(isCC && DEBUG_RA) {
- cout << "\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) {
- cout << " added to an existing LR for def: ";
- printValue( Def ); cout << endl;
- }
- }
-
-
-
- } // 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).isDef()) {
+ const Value *Def = MInst->getImplicitRef(i);
+ LiveRange* LR = createOrAddToLiveRange(Def, /*isCC*/ false);
+
+ // If the implicit operand has a pre-assigned register,
+ // set it directly in the LiveRange
+ if (MInst->getImplicitOp(i).hasAllocatedReg()) {
+ unsigned getClassId;
+ LR->setColor(MRI.getClassRegNum(
+ MInst->getImplicitOp(i).getReg(),
+ getClassId));
+ }
+ }
} // for all machine instructions in the BB
+ } // for all BBs in function
- } // for all BBs in method
+ // 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 >= RA_DEBUG_LiveRanges)
+ std::cerr << "Initial Live Ranges constructed!\n";
+}
- if( DEBUG_RA)
- cout << "Initial Live Ranges constructed!" << endl;
+//---------------------------------------------------------------------------
+// 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 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() {
+ 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" );
+ }
}
+//--------------------------------------------------------------------------
+// The following method coalesces live ranges when possible. This method
+// must be called after the interference graph has been constructed.
-void LiveRangeInfo::coalesceLRs()
-{
/* 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
- if the def and op are of the same type
+ if the def and op are of the same register type
if the def and op do not interfere //i.e., not simultaneously live
if (degree(LR of def) + degree(LR of op)) <= # avail regs
- merge2IGNodes(def, op) // i.e., merge 2 LRs
+ if both LRs do not have suggested colors
+ merge2IGNodes(def, op) // i.e., merge 2 LRs
*/
+//---------------------------------------------------------------------------
+
+
+// Checks if live range LR interferes with any node assigned or suggested to
+// be assigned the specified color
+//
+inline bool InterferesWithColor(const LiveRange& LR, unsigned color) {
+ IGNode* lrNode = LR.getUserIGNode();
+ for (unsigned n=0, NN = lrNode->getNumOfNeighbors(); n < NN; n++) {
+ LiveRange *neighLR = lrNode->getAdjIGNode(n)->getParentLR();
+ if (neighLR->hasColor() && neighLR->getColor() == color)
+ return true;
+ if (neighLR->hasSuggestedColor() && neighLR->getSuggestedColor() == color)
+ return true;
+ }
+ return false;
+}
- if( DEBUG_RA)
- cout << endl << "Coalscing LRs ..." << endl;
+// Cannot coalesce if any of the following is true:
+// (1) Both LRs have suggested colors (should be "different suggested colors"?)
+// (2) Both LR1 and LR2 have colors and the colors are different
+// (but if the colors are the same, it is definitely safe to coalesce)
+// (3) LR1 has color and LR2 interferes with any LR that has the same color
+// (4) LR2 has color and LR1 interferes with any LR that has the same color
+//
+inline bool InterfsPreventCoalescing(const LiveRange& LROfDef,
+ const LiveRange& LROfUse) {
+ // (4) if they have different suggested colors, cannot coalesce
+ if (LROfDef.hasSuggestedColor() && LROfUse.hasSuggestedColor())
+ return true;
+
+ // if neither has a color, nothing more to do.
+ if (! LROfDef.hasColor() && ! LROfUse.hasColor())
+ return false;
+
+ // (2, 3) if L1 has color...
+ if (LROfDef.hasColor()) {
+ if (LROfUse.hasColor())
+ return (LROfUse.getColor() != LROfDef.getColor());
+ return InterferesWithColor(LROfUse, LROfDef.getColor());
+ }
+
+ // (4) else only LROfUse has a color: check if that could interfere
+ return InterferesWithColor(LROfDef, LROfUse.getColor());
+}
- Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
- for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
+void LiveRangeInfo::coalesceLRs()
+{
+ if(DEBUG_RA >= RA_DEBUG_LiveRanges)
+ std::cerr << "\nCoalescing LRs ...\n";
- // 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) {
- cout << " *Iterating over machine instr ";
- MInst->dump();
- cout << endl;
+ if( DEBUG_RA >= RA_DEBUG_LiveRanges) {
+ std::cerr << " *Iterating over machine instr ";
+ MI->dump();
+ std::cerr << "\n";
}
-
// iterate over MI operands to find defs
- for(MachineInstr::val_op_const_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_op_const_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.isDef()) { // 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) {
- cout<<" !! Warning: No LR for use "; printValue(*UseI);
- cout << endl;
- }
+ if (!isa<BasicBlock>(*UseI) && DEBUG_RA >= RA_DEBUG_LiveRanges)
+ std::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( LROfUse->getTypeID() == LROfDef->getTypeID() ) {
-
- if( ! RCOfDef->getInterference(LROfDef, LROfUse) ) {
+ if (MRI.getRegTypeForLR(LROfDef) ==
+ MRI.getRegTypeForLR(LROfUse)) {
+ // If the two RegTypes are the same
+ 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());
+ }
- RCOfDef->mergeIGNodesOfLRs(LROfDef, LROfUse);
- unionAndUpdateLRs(LROfDef, LROfUse);
+ if (CombinedDegree <= RCOfDef->getNumOfAvailRegs()) {
+ // if both LRs do not have different pre-assigned colors
+ // and both LRs do not have suggested colors
+ if (! InterfsPreventCoalescing(*LROfDef, *LROfUse)) {
+ 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
-
+ }// if reg classes are the same
} // for all uses
-
} // if def
-
} // for all defs
-
} // for all machine instructions
-
} // for all BBs
- if( DEBUG_RA)
- cout << endl << "Coalscing Done!" << endl;
-
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges)
+ std::cerr << "\nCoalescing Done!\n";
}
-
-
-
-
/*--------------------------- Debug code for printing ---------------*/
-void LiveRangeInfo::printLiveRanges()
-{
+void LiveRangeInfo::printLiveRanges() {
LiveRangeMapType::iterator HMI = LiveRangeMap.begin(); // hash map iterator
- cout << endl << "Printing Live Ranges from Hash Map:" << endl;
- for( ; HMI != LiveRangeMap.end() ; HMI ++ ) {
- if( (*HMI).first ) {
- cout <<" "; printValue((*HMI).first); cout << "\t: ";
- ((*HMI).second)->printSet(); cout << endl;
+ std::cerr << "\nPrinting Live Ranges from Hash Map:\n";
+ for( ; HMI != LiveRangeMap.end(); ++HMI) {
+ if (HMI->first && HMI->second) {
+ std::cerr << " Value* " << RAV(HMI->first) << "\t: ";
+ if (IGNode* igNode = HMI->second->getUserIGNode())
+ std::cerr << "LR# " << igNode->getIndex();
+ else
+ std::cerr << "LR# " << "<no-IGNode>";
+ std::cerr << "\t:Values = "; printSet(*HMI->second); std::cerr << "\n";
}
}
}
-
+} // End llvm namespace
projects / oota-llvm.git / blobdiff