llvm-6502/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
Chris Lattner 045e7c8434 Change debug info from #define to command line option
Clean up extra debug info that wasn't guarded


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@647 91177308-0d34-0410-b5e6-96231b3b80d8
2001-09-19 16:26:23 +00:00

497 lines
16 KiB
C++

#include "llvm/CodeGen/PhyRegAlloc.h"
cl::Enum<RegAllocDebugLevel_t> DEBUG_RA("dregalloc", cl::NoFlags,
"enable register allocation debugging information",
clEnumValN(RA_DEBUG_None , "n", "disable debug output"),
clEnumValN(RA_DEBUG_Normal , "y", "enable debug output"),
clEnumValN(RA_DEBUG_Verbose, "v", "enable extra debug output"), 0);
//----------------------------------------------------------------------------
// Constructor: Init local composite objects and create register classes.
//----------------------------------------------------------------------------
PhyRegAlloc::PhyRegAlloc(const Method *const M,
const TargetMachine& tm,
MethodLiveVarInfo *const Lvi)
: RegClassList(),
Meth(M), TM(tm), LVI(Lvi), LRI(M, tm, RegClassList),
MRI( tm.getRegInfo() ),
NumOfRegClasses(MRI.getNumOfRegClasses()),
CallInstrList(),
RetInstrList(),
AddedInstrMap()
{
// **TODO: use an actual reserved color list
ReservedColorListType *RCL = new ReservedColorListType();
// create each RegisterClass and put in RegClassList
for( unsigned int rc=0; rc < NumOfRegClasses; rc++)
RegClassList.push_back( new RegClass(M, MRI.getMachineRegClass(rc), RCL) );
}
//----------------------------------------------------------------------------
// This method initally creates interference graphs (one in each reg class)
// and IGNodeList (one in each IG). The actual nodes will be pushed later.
//----------------------------------------------------------------------------
void PhyRegAlloc::createIGNodeListsAndIGs()
{
if(DEBUG_RA ) cout << "Creating LR lists ..." << endl;
// hash map iterator
LiveRangeMapType::const_iterator HMI = (LRI.getLiveRangeMap())->begin();
// hash map end
LiveRangeMapType::const_iterator HMIEnd = (LRI.getLiveRangeMap())->end();
for( ; HMI != HMIEnd ; ++HMI ) {
LiveRange *L = (*HMI).second; // get the LiveRange
if( (*HMI).first ) {
// if the Value * is not null, and LR
// is not yet written to the IGNodeList
if( !(L->getUserIGNode()) ) {
RegClass *const RC = // RegClass of first value in the LR
//RegClassList [MRI.getRegClassIDOfValue(*(L->begin()))];
RegClassList[ L->getRegClass()->getID() ];
RC-> addLRToIG( L ); // add this LR to an IG
}
}
}
// init RegClassList
for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
RegClassList[ rc ]->createInterferenceGraph();
if( DEBUG_RA)
cout << "LRLists Created!" << endl;
}
//----------------------------------------------------------------------------
// This method will add all interferences at for a given instruction.
// Interence occurs only if the LR of Def (Inst or Arg) is of the same reg
// class as that of live var. The live var passed to this function is the
// LVset AFTER the instruction
//----------------------------------------------------------------------------
void PhyRegAlloc::addInterference(const Value *const Def,
const LiveVarSet *const LVSet,
const bool isCallInst) {
LiveVarSet::const_iterator LIt = LVSet->begin();
// get the live range of instruction
const LiveRange *const LROfDef = LRI.getLiveRangeForValue( Def );
IGNode *const IGNodeOfDef = LROfDef->getUserIGNode();
assert( IGNodeOfDef );
RegClass *const RCOfDef = LROfDef->getRegClass();
// for each live var in live variable set
for( ; LIt != LVSet->end(); ++LIt) {
if( DEBUG_RA > 1) {
cout << "< Def="; printValue(Def);
cout << ", Lvar="; printValue( *LIt); cout << "> ";
}
// get the live range corresponding to live var
LiveRange *const LROfVar = LRI.getLiveRangeForValue(*LIt );
// LROfVar can be null if it is a const since a const
// doesn't have a dominating def - see Assumptions above
if( LROfVar) {
if(LROfDef == LROfVar) // do not set interf for same LR
continue;
// if 2 reg classes are the same set interference
if( RCOfDef == LROfVar->getRegClass() ){
RCOfDef->setInterference( LROfDef, LROfVar);
}
//the live range of this var interferes with this call
if( isCallInst )
LROfVar->addCallInterference( (const Instruction *const) Def );
}
else if(DEBUG_RA > 1) {
// we will not have LRs for values not explicitly allocated in the
// instruction stream (e.g., constants)
cout << " warning: no live range for " ;
printValue( *LIt); cout << endl; }
}
}
//----------------------------------------------------------------------------
// This method will walk thru code and create interferences in the IG of
// each RegClass.
//----------------------------------------------------------------------------
void PhyRegAlloc::buildInterferenceGraphs()
{
if(DEBUG_RA) cout << "Creating interference graphs ..." << endl;
Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
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();
// iterate over all the machine instructions in BB
for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
const MachineInstr *const MInst = *MInstIterator;
// get the LV set after the instruction
const LiveVarSet *const LVSetAI =
LVI->getLiveVarSetAfterMInst(MInst, *BBI);
const bool isCallInst = TM.getInstrInfo().isCall(MInst->getOpCode());
// iterate over MI operands to find defs
for( MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done(); ++OpI) {
if( OpI.isDef() ) {
// create a new LR iff this operand is a def
addInterference(*OpI, LVSetAI, isCallInst );
} //if this is a def
} // for all operands
} // for all machine instructions in BB
// go thru LLVM instructions in the basic block and record all CALL
// instructions and Return instructions in the CallInstrList
// This is done because since there are no reverse pointers in machine
// instructions to find the llvm instruction, when we encounter a call
// or a return whose args must be specailly colored (e.g., %o's for args)
BasicBlock::const_iterator InstIt = (*BBI)->begin();
for( ; InstIt != (*BBI)->end() ; ++ InstIt) {
unsigned OpCode = (*InstIt)->getOpcode();
if( OpCode == Instruction::Call )
CallInstrList.push_back( *InstIt );
else if( OpCode == Instruction::Ret )
RetInstrList.push_back( *InstIt );
}
} // for all BBs in method
// add interferences for method arguments. Since there are no explict
// defs in method for args, we have to add them manually
addInterferencesForArgs(); // add interference for method args
if( DEBUG_RA)
cout << "Interference graphs calculted!" << endl;
}
//----------------------------------------------------------------------------
// This method will add interferences for incoming arguments to a method.
//----------------------------------------------------------------------------
void PhyRegAlloc::addInterferencesForArgs()
{
// get the InSet of root BB
const LiveVarSet *const InSet = LVI->getInSetOfBB( Meth->front() );
// 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
addInterference( *ArgIt, InSet, false ); // add interferences between
// args and LVars at start
if( DEBUG_RA > 1) {
cout << " - %% adding interference for argument ";
printValue( (const Value *) *ArgIt); cout << endl;
}
}
}
//----------------------------------------------------------------------------
// This method is called after register allocation is complete to set the
// allocated reisters in the machine code. This code will add register numbers
// to MachineOperands that contain a Value.
//----------------------------------------------------------------------------
void PhyRegAlloc::updateMachineCode()
{
Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
// get the iterator for machine instructions
MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
MachineCodeForBasicBlock::iterator MInstIterator = MIVec.begin();
// iterate over all the machine instructions in BB
for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
MachineInstr *const MInst = *MInstIterator;
//for(MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done();++OpI) {
for(unsigned OpNum=0; OpNum < MInst->getNumOperands(); ++OpNum) {
MachineOperand& Op = MInst->getOperand(OpNum);
if( Op.getOperandType() == MachineOperand::MO_VirtualRegister ||
Op.getOperandType() == MachineOperand::MO_CCRegister) {
const Value *const Val = Op.getVRegValue();
// delete this condition checking later (must assert if Val is null)
if( !Val) {
if (DEBUG_RA)
cout << "Warning: NULL Value found for operand" << endl;
continue;
}
assert( Val && "Value is NULL");
const LiveRange *const LR = LRI.getLiveRangeForValue(Val);
if ( !LR ) {
// nothing to worry if it's a const or a label
if (DEBUG_RA) {
cout << "*NO LR for inst opcode: ";
cout << TargetInstrDescriptors[MInst->getOpCode()].opCodeString;
}
Op.setRegForValue( -1 ); // mark register as invalid
if( ((Val->getType())->isLabelType()) ||
(Val->getValueType() == Value::ConstantVal) )
; // do nothing
// The return address is not explicitly defined within a
// method. So, it is not colored by usual algorithm. In that case
// color it here.
//else if (TM.getInstrInfo().isCall(MInst->getOpCode()))
//Op.setRegForValue( MRI.getCallAddressReg() );
//TM.getInstrInfo().isReturn(MInst->getOpCode())
else if(TM.getInstrInfo().isReturn(MInst->getOpCode()) ) {
if (DEBUG_RA) cout << endl << "RETURN found" << endl;
Op.setRegForValue( MRI.getReturnAddressReg() );
}
else
{
cout << "!Warning: No LiveRange for: ";
printValue( Val); cout << " Type: " << Val->getValueType();
cout << " RegVal=" << Op.getAllocatedRegNum() << endl;
}
continue;
}
unsigned RCID = (LR->getRegClass())->getID();
Op.setRegForValue( MRI.getUnifiedRegNum(RCID, LR->getColor()) );
int RegNum = MRI.getUnifiedRegNum(RCID, LR->getColor());
}
}
}
}
}
//----------------------------------------------------------------------------
// This method prints the code with registers after register allocation is
// complete.
//----------------------------------------------------------------------------
void PhyRegAlloc::printMachineCode()
{
cout << endl << ";************** Method ";
cout << Meth->getName() << " *****************" << endl;
Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
for( ; BBI != Meth->end(); ++BBI) { // traverse BBs in random order
cout << endl ; printLabel( *BBI); cout << ": ";
// get the iterator for machine instructions
MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
MachineCodeForBasicBlock::iterator MInstIterator = MIVec.begin();
// iterate over all the machine instructions in BB
for( ; MInstIterator != MIVec.end(); ++MInstIterator) {
MachineInstr *const MInst = *MInstIterator;
cout << endl << "\t";
cout << TargetInstrDescriptors[MInst->getOpCode()].opCodeString;
//for(MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done();++OpI) {
for(unsigned OpNum=0; OpNum < MInst->getNumOperands(); ++OpNum) {
MachineOperand& Op = MInst->getOperand(OpNum);
if( Op.getOperandType() == MachineOperand::MO_VirtualRegister ||
Op.getOperandType() == MachineOperand::MO_CCRegister ||
Op.getOperandType() == MachineOperand::MO_PCRelativeDisp ) {
const Value *const Val = Op.getVRegValue () ;
// ****this code is temporary till NULL Values are fixed
if( ! Val ) {
cout << "\t<*NULL*>";
continue;
}
// if a label or a constant
if( (Val->getValueType() == Value::BasicBlockVal) ||
(Val->getValueType() == Value::ConstantVal) ) {
cout << "\t"; printLabel( Op.getVRegValue () );
}
else {
// else it must be a register value
const int RegNum = Op.getAllocatedRegNum();
cout << "\t" << "%" << MRI.getUnifiedRegName( RegNum );
}
}
else if(Op.getOperandType() == MachineOperand::MO_MachineRegister) {
cout << "\t" << "%" << MRI.getUnifiedRegName(Op.getMachineRegNum());
}
else
cout << "\t" << Op; // use dump field
}
}
cout << endl;
}
cout << endl;
}
//----------------------------------------------------------------------------
// Used to generate a label for a basic block
//----------------------------------------------------------------------------
void PhyRegAlloc::printLabel(const Value *const Val)
{
if( Val->hasName() )
cout << Val->getName();
else
cout << "Label" << Val;
}
//----------------------------------------------------------------------------
// The entry pont to Register Allocation
//----------------------------------------------------------------------------
void PhyRegAlloc::allocateRegisters()
{
constructLiveRanges(); // create LR info
if( DEBUG_RA)
LRI.printLiveRanges();
createIGNodeListsAndIGs(); // create IGNode list and IGs
buildInterferenceGraphs(); // build IGs in all reg classes
if( DEBUG_RA) {
// print all LRs in all reg classes
for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
RegClassList[ rc ]->printIGNodeList();
// print IGs in all register classes
for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
RegClassList[ rc ]->printIG();
}
LRI.coalesceLRs(); // coalesce all live ranges
if( DEBUG_RA) {
// print all LRs in all reg classes
for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
RegClassList[ rc ]->printIGNodeList();
// print IGs in all register classes
for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
RegClassList[ rc ]->printIG();
}
// the following three calls must be made in that order since
// coloring or definitions must come before their uses
MRI.colorArgs(Meth, LRI); // color method args
// color call args of call instrns
MRI.colorCallArgs(CallInstrList, LRI, AddedInstrMap);
// color return args
MRI.colorRetArg(CallInstrList, LRI, AddedInstrMap);
// color all register classes
for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)
RegClassList[ rc ]->colorAllRegs();
updateMachineCode();
if (DEBUG_RA) {
PrintMachineInstructions(Meth);
printMachineCode(); // only for DEBUGGING
}
}