--added suggesting colors; call/ret arg handling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@670 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp b/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
index 658f3d2..4d3e925 100644
--- a/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
+++ b/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
@@ -4,12 +4,15 @@
const TargetMachine& tm,
vector<RegClass *> &RCL)
: Meth(M), LiveRangeMap(),
- TM(tm), RegClassList(RCL)
+ TM(tm), RegClassList(RCL),
+ MRI( tm.getRegInfo()),
+ CallRetInstrList()
{ }
// 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)
{
@@ -24,6 +27,15 @@
L1->add( *L2It ); // add the var in L2 to L1
LiveRangeMap[ *L2It ] = L1; // now the elements in L2 should map to L1
}
+
+
+ // Now if LROfDef(L1) has a suggested color, it will remain.
+ // But, 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
}
@@ -58,7 +70,7 @@
// create a temp machine op to find the register class of value
//const MachineOperand Op(MachineOperand::MO_VirtualRegister);
- unsigned rcid = (TM.getRegInfo()).getRegClassIDOfValue( Val );
+ unsigned rcid = MRI.getRegClassIDOfValue( Val );
ArgRange->setRegClass(RegClassList[ rcid ] );
@@ -68,16 +80,24 @@
}
}
+ // Now suggest hardware registers for these method args
+ MRI.suggestRegs4MethodArgs(Meth, *this);
- // 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 find speical LLVM instructions (CALL, RET) and LRs in machine
+ // instructions.
+
Method::const_iterator BBI = Meth->begin(); // random iterator for BBs
for( ; BBI != Meth->end(); ++BBI) { // go thru BBs in random order
+ // 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
const MachineCodeForBasicBlock& MIVec = (*BBI)->getMachineInstrVec();
MachineCodeForBasicBlock::const_iterator
@@ -87,12 +107,20 @@
for( ; MInstIterator != MIVec.end(); MInstIterator++) {
const MachineInstr * MInst = *MInstIterator;
+
+ // Now if the machine instruction has special operands that must be
+ // set with a "suggested color", do it here.
+
+
+ if( MRI.handleSpecialMInstr(MInst, *this, RegClassList) )
+ continue;
+
// iterate over MI operands to find defs
- for( MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done(); OpI++) {
+ for( MachineInstr::val_op_const_iterator OpI(MInst);!OpI.done(); ++OpI) {
- // delete later from here ************
+ // delete later from here ************
MachineOperand::MachineOperandType OpTyp =
OpI.getMachineOperand().getOperandType();
@@ -104,11 +132,21 @@
// ************* to here
-
// 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 ) {
+ cout << "\n**%%Error: Def is not an instruction val. Def=";
+ printValue( Def ); cout << endl;
+ continue;
+ }
+
+
LiveRange *DefRange = LiveRangeMap[Def];
// see LR already there (because of multiple defs)
@@ -130,7 +168,7 @@
OpI.getMachineOperand().getOperandType();
bool isCC = ( OpTy == MachineOperand::MO_CCRegister);
- unsigned rcid = (TM.getRegInfo()).getRegClassIDOfValue(
+ unsigned rcid = MRI.getRegClassIDOfValue(
OpI.getMachineOperand().getVRegValue(), isCC );
@@ -163,6 +201,42 @@
} // for all machine instructions in the BB
+
+ } // for all BBs in method
+
+ // go thru LLVM instructions in the basic block and suggest colors
+ // for their args. Also record all CALL
+ // instructions and Return instructions in the CallRetInstrList
+ // 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)
+ // We have to makes sure that all LRs of call/ret args are added before
+ // doing this. But return value of call will not have a LR.
+
+ BBI = Meth->begin(); // random iterator for BBs
+
+ for( ; BBI != Meth->end(); ++BBI) { // go thru BBs in random order
+
+ BasicBlock::const_iterator InstIt = (*BBI)->begin();
+
+ for( ; InstIt != (*BBI)->end() ; ++InstIt) {
+
+ const Instruction *const CallRetI = *InstIt;
+ unsigned OpCode = (CallRetI)->getOpcode();
+
+ if( (OpCode == Instruction::Call) ) {
+ CallRetInstrList.push_back(CallRetI );
+ MRI.suggestRegs4CallArgs( (CallInst *) CallRetI, *this, RegClassList );
+ }
+
+ else if (OpCode == Instruction::Ret ) {
+ CallRetInstrList.push_back( CallRetI );
+ MRI.suggestReg4RetValue( (ReturnInst *) CallRetI, *this);
+ }
+
+
+ } // for each llvm instr in BB
+
} // for all BBs in method
if( DEBUG_RA)
@@ -183,7 +257,8 @@
if the def and op are of the same 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
*/
@@ -253,8 +328,14 @@
if( CombinedDegree <= RCOfDef->getNumOfAvailRegs() ) {
- RCOfDef->mergeIGNodesOfLRs(LROfDef, LROfUse);
- unionAndUpdateLRs(LROfDef, LROfUse);
+ // if both LRs do not have suggested colors
+ if( ! (LROfDef->hasSuggestedColor() &&
+ LROfUse->hasSuggestedColor() ) ) {
+
+ RCOfDef->mergeIGNodesOfLRs(LROfDef, LROfUse);
+ unionAndUpdateLRs(LROfDef, LROfUse);
+ }
+
} // if combined degree is less than # of regs
@@ -289,7 +370,7 @@
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 ) {
+ if( (*HMI).first && (*HMI).second ) {
cout <<" "; printValue((*HMI).first); cout << "\t: ";
((*HMI).second)->printSet(); cout << endl;
}