[llvm-commits] CVS: llvm/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
Vikram Adve
vadve at cs.uiuc.edu
Sat Sep 28 12:06:01 PDT 2002
Changes in directory llvm/lib/CodeGen/RegAlloc:
LiveRangeInfo.cpp updated: 1.28 -> 1.29
---
Log message:
Live ranges for Return value and return address of a Call are now
created here, simply by handling all implicit operands (which should
have been done anyway).
---
Diffs of the changes:
Index: llvm/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
diff -u llvm/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp:1.28 llvm/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp:1.29
--- llvm/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp:1.28 Thu Sep 19 19:45:47 2002
+++ llvm/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp Sat Sep 28 12:05:22 2002
@@ -78,6 +78,48 @@
}
+//---------------------------------------------------------------------------
+// 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.
+//---------------------------------------------------------------------------
+
+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.getRegClassIDOfValue(Def, isCC)]);
+
+ if (DEBUG_RA >= RA_DEBUG_LiveRanges) {
+ cerr << " Creating a LR for def ";
+ if (isCC) cerr << " (CC Register!)";
+ cerr << " : " << RAV(Def) << "\n";
+ }
+ return DefRange;
+}
+
+
+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 = this->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;
+}
+
//---------------------------------------------------------------------------
// Method for constructing all live ranges in a function. It creates live
@@ -91,128 +133,66 @@
// 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){
- LiveRange *ArgRange = new LiveRange(); // creates a new LR and
- ArgRange->insert(AI); // add the arg (def) to it
- LiveRangeMap[AI] = ArgRange;
-
- // create a temp machine op to find the register class of value
- //const MachineOperand Op(MachineOperand::MO_VirtualRegister);
-
- unsigned rcid = MRI.getRegClassIDOfValue(AI);
- ArgRange->setRegClass(RegClassList[rcid]);
-
-
- if( DEBUG_RA >= RA_DEBUG_LiveRanges)
- cerr << " Adding LiveRange for argument " << RAV(AI) << "\n";
- }
+ for (Function::const_aiterator AI = Meth->abegin(); AI != Meth->aend(); ++AI)
+ this->createNewLiveRange(AI, /*isCC*/ false);
// Now suggest hardware registers for these function args
MRI.suggestRegs4MethodArgs(Meth, *this);
-
- // Now find speical LLVM instructions (CALL, RET) and LRs in machine
- // instructions.
+ // 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.
//
for (Function::const_iterator BBI=Meth->begin(); BBI != Meth->end(); ++BBI){
- // 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.
-
- // get the iterator for machine instructions
+ // get the vector of machine instructions for this basic block.
MachineCodeForBasicBlock& MIVec = MachineCodeForBasicBlock::get(BBI);
-
+
// iterate over all the machine instructions in BB
for(MachineCodeForBasicBlock::iterator MInstIterator = MIVec.begin();
MInstIterator != MIVec.end(); ++MInstIterator) {
MachineInstr *MInst = *MInstIterator;
- // Now if the machine instruction is a call/return instruction,
- // add it to CallRetInstrList for processing its implicit operands
-
+ // 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 MI operands to find defs
+ // 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(DEBUG_RA >= RA_DEBUG_LiveRanges) {
- MachineOperand::MachineOperandType OpTyp =
- OpI.getMachineOperand().getOperandType();
-
- if (OpTyp == MachineOperand::MO_CCRegister)
- cerr << "\n**CC reg found. Is Def=" << OpI.isDef() << " Val:"
- << RAV(OpI.getMachineOperand().getVRegValue()) << "\n";
- }
-
- // create a new LR iff this operand is a def
+ OpE = MInst->end(); OpI != OpE; ++OpI)
if (OpI.isDef()) {
const Value *Def = *OpI;
+ bool isCC = (OpI.getMachineOperand().getOperandType()
+ == MachineOperand::MO_CCRegister);
+ this->createOrAddToLiveRange(Def, isCC);
+ }
- // Only instruction values are accepted for live ranges here
- if (Def->getValueType() != Value::InstructionVal ) {
- cerr << "\n**%%Error: Def is not an instruction val. Def="
- << RAV(Def) << "\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->insert(Def); // add the instruction (def) to it
- LiveRangeMap[ Def ] = DefRange; // update the map
-
- if (DEBUG_RA >= RA_DEBUG_LiveRanges)
- cerr << " creating a LR for def: " << RAV(Def) << "\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 >= RA_DEBUG_LiveRanges)
- cerr << "\a**created a LR for a CC reg:"
- << RAV(OpI.getMachineOperand().getVRegValue());
-
- DefRange->setRegClass(RegClassList[rcid]);
- } else {
- DefRange->insert(Def); // add the opearand to def range
- // update the map - Operand points
- // to the merged set
- LiveRangeMap[Def] = DefRange;
-
- if (DEBUG_RA >= RA_DEBUG_LiveRanges)
- cerr << " Added to existing LR for def: " << RAV(Def) << "\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->implicitRefIsDefined(i)) {
+ const Value *Def = MInst->getImplicitRef(i);
+ this->createOrAddToLiveRange(Def, /*isCC*/ false);
+ }
} // for all machine instructions in the BB
} // 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 >= RA_DEBUG_LiveRanges)
cerr << "Initial Live Ranges constructed!\n";
-
}
@@ -236,7 +216,7 @@
MRI.suggestReg4RetValue( MInst, *this);
else if( (TM.getInstrInfo()).isCall( OpCode ) )
- MRI.suggestRegs4CallArgs( MInst, *this, RegClassList );
+ MRI.suggestRegs4CallArgs( MInst, *this);
else
assert( 0 && "Non call/ret instr in CallRetInstrList" );
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