-#include "llvm/Analysis/LiveVar/BBLiveVar.h"
-#include "llvm/Analysis/LiveVar/MethodLiveVarInfo.h"
+//===-- BBLiveVar.cpp - Live Variable Analysis for a BasicBlock -----------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a wrapper class for BasicBlock which is used by live var analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BBLiveVar.h"
+#include "llvm/CodeGen/FunctionLiveVarInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/Sparc.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/Support/CFG.h"
+#include "Support/SetOperations.h"
+#include "../SparcInternals.h"
+namespace llvm {
-/********************* Implementation **************************************/
+BBLiveVar::BBLiveVar(const BasicBlock &bb,
+ const MachineBasicBlock &mbb,
+ unsigned id)
+ : BB(bb), MBB(mbb), POID(id) {
+ InSetChanged = OutSetChanged = false;
-BBLiveVar::BBLiveVar( const BasicBlock *const baseBB, unsigned int RdfoId)
- : BaseBB(baseBB), DefSet(), InSet(),
- OutSet(), PhiArgMap() {
- BaseBB = baseBB;
- InSetChanged = OutSetChanged = false;
- POId = RdfoId;
+ calcDefUseSets();
}
-// caluculates def and use sets for each BB
+//-----------------------------------------------------------------------------
+// calculates def and use sets for each BB
// There are two passes over operands of a machine instruction. This is
// because, we can have instructions like V = V + 1, since we no longer
// assume single definition.
+//-----------------------------------------------------------------------------
-void BBLiveVar::calcDefUseSets()
-{
- // get the iterator for machine instructions
- const MachineCodeForBasicBlock& MIVec = BaseBB->getMachineInstrVec();
- MachineCodeForBasicBlock::const_reverse_iterator
- MInstIterator = MIVec.rbegin();
-
+void BBLiveVar::calcDefUseSets() {
// iterate over all the machine instructions in BB
- for( ; MInstIterator != MIVec.rend(); ++MInstIterator) {
-
- const MachineInstr * MInst = *MInstIterator; // MInst is the machine inst
- assert(MInst);
+ for (MachineBasicBlock::const_reverse_iterator MII = MBB.rbegin(),
+ MIE = MBB.rend(); MII != MIE; ++MII) {
+ const MachineInstr *MI = *MII;
- if( DEBUG_LV > 1) { // debug msg
- cout << " *Iterating over machine instr ";
- MInst->dump();
- cout << endl;
+ if (DEBUG_LV >= LV_DEBUG_Verbose) {
+ std::cerr << " *Iterating over machine instr ";
+ MI->dump();
+ std::cerr << "\n";
}
// iterate over MI operands to find defs
- for( MachineInstr::val_op_const_iterator OpI(MInst); !OpI.done() ; ++OpI) {
-
- const Value *Op = *OpI;
-
- if( OpI.isDef() ) { // add to Defs only if this operand is a def
-
- DefSet.add( Op ); // operand is a def - so add to def set
- InSet.remove( Op); // this definition kills any uses
- InSetChanged = true;
-
- if( DEBUG_LV > 1) {
- cout << " +Def: "; printValue( Op ); cout << endl;
- }
- }
- }
-
- bool IsPhi = ( MInst->getOpCode() == PHI );
-
-
- // iterate over MI operands to find uses
- for(MachineInstr::val_op_const_iterator OpI(MInst); !OpI.done() ; ++OpI) {
+ for (MachineInstr::const_val_op_iterator OpI = MI->begin(), OpE = MI->end();
+ OpI != OpE; ++OpI)
+ if (OpI.isDef()) // add to Defs if this operand is a def
+ addDef(*OpI);
+
+ // do for implicit operands as well
+ for (unsigned i = 0; i < MI->getNumImplicitRefs(); ++i)
+ if (MI->getImplicitOp(i).isDef())
+ addDef(MI->getImplicitRef(i));
+
+ // iterate over MI operands to find uses
+ for (MachineInstr::const_val_op_iterator OpI = MI->begin(), OpE = MI->end();
+ OpI != OpE; ++OpI) {
const Value *Op = *OpI;
- if ( ((Op)->getType())->isLabelType() )
+ if (isa<BasicBlock>(Op))
continue; // don't process labels
- if(! OpI.isDef() ) { // add to Defs only if this operand is a use
-
- InSet.add( Op ); // An operand is a use - so add to use set
- OutSet.remove( Op ); // remove if there is a def below this use
- InSetChanged = true;
-
- if( DEBUG_LV > 1) { // debug msg of level 2
- cout << " Use: "; printValue( Op ); cout << endl;
- }
-
- if( IsPhi ) { // for a phi node
- // put args into the PhiArgMap (Val -> BB)
-
- const Value * ArgVal = Op;
- ++OpI; // increment to point to BB of value
- const Value * BBVal = *OpI;
-
-
- assert( (BBVal)->getValueType() == Value::BasicBlockVal );
+ if (OpI.isUse()) { // add to Uses only if this operand is a use
+ //
+ // *** WARNING: The following code for handling dummy PHI machine
+ // instructions is untested. The previous code was broken and I
+ // fixed it, but it turned out to be unused as long as Phi
+ // elimination is performed during instruction selection.
+ //
+ // Put Phi operands in UseSet for the incoming edge, not node.
+ // They must not "hide" later defs, and must be handled specially
+ // during set propagation over the CFG.
+ if (MI->getOpCode() == V9::PHI) { // for a phi node
+ const Value *ArgVal = Op;
+ const BasicBlock *PredBB = cast<BasicBlock>(*++OpI); // next ptr is BB
+
+ PredToEdgeInSetMap[PredBB].insert(ArgVal);
- PhiArgMap[ ArgVal ] = (const BasicBlock *) (BBVal);
- assert( PhiArgMap[ ArgVal ] );
+ if (DEBUG_LV >= LV_DEBUG_Verbose)
+ std::cerr << " - phi operand " << RAV(ArgVal) << " came from BB "
+ << RAV(PredBB) << "\n";
+ } // if( IsPhi )
+ else {
+ // It is not a Phi use: add to regular use set and remove later defs.
+ addUse(Op);
+ }
+ } // if a use
+ } // for all operands
+
+ // do for implicit operands as well
+ for (unsigned i = 0; i < MI->getNumImplicitRefs(); ++i) {
+ assert(MI->getOpCode() != V9::PHI && "Phi cannot have implicit operands");
+ const Value *Op = MI->getImplicitRef(i);
+
+ if (Op->getType() == Type::LabelTy) // don't process labels
+ continue;
+
+ if (MI->getImplicitOp(i).isUse())
+ addUse(Op);
+ }
+ } // for all machine instructions
+}
- if( DEBUG_LV > 1) { // debug msg of level 2
- cout << " - phi operand ";
- printValue( ArgVal );
- cout << " came from BB ";
- printValue( PhiArgMap[ ArgVal ]);
- cout<<endl;
- }
- }
+
+//-----------------------------------------------------------------------------
+// To add an operand which is a def
+//-----------------------------------------------------------------------------
+void BBLiveVar::addDef(const Value *Op) {
+ DefSet.insert(Op); // operand is a def - so add to def set
+ InSet.erase(Op); // this definition kills any later uses
+ InSetChanged = true;
+
+ if (DEBUG_LV >= LV_DEBUG_Verbose) std::cerr << " +Def: " << RAV(Op) << "\n";
+}
- }
- }
- } // for all machine instructions
-}
-
+//-----------------------------------------------------------------------------
+// To add an operand which is a use
+//-----------------------------------------------------------------------------
+void BBLiveVar::addUse(const Value *Op) {
+ InSet.insert(Op); // An operand is a use - so add to use set
+ DefSet.erase(Op); // remove if there is a def below this use
+ InSetChanged = true;
+
+ if (DEBUG_LV >= LV_DEBUG_Verbose) std::cerr << " Use: " << RAV(Op) << "\n";
+}
-bool BBLiveVar::applyTransferFunc() // calculates the InSet in terms of OutSet
-{
+//-----------------------------------------------------------------------------
+// Applies the transfer function to a basic block to produce the InSet using
+// the OutSet.
+//-----------------------------------------------------------------------------
+bool BBLiveVar::applyTransferFunc() {
// IMPORTANT: caller should check whether the OutSet changed
// (else no point in calling)
- LiveVarSet OutMinusDef; // set to hold (Out[B] - Def[B])
- OutMinusDef.setDifference( &OutSet, &DefSet);
- InSetChanged = InSet.setUnion( &OutMinusDef );
+ ValueSet OutMinusDef = set_difference(OutSet, DefSet);
+ InSetChanged = set_union(InSet, OutMinusDef);
OutSetChanged = false; // no change to OutSet since transf func applied
-
return InSetChanged;
}
+//-----------------------------------------------------------------------------
+// calculates Out set using In sets of the successors
+//-----------------------------------------------------------------------------
-// calculates Out set using In sets of the predecessors
-bool BBLiveVar::setPropagate( LiveVarSet *const OutSet,
- const LiveVarSet *const InSet,
- const BasicBlock *const PredBB) {
-
- LiveVarSet::const_iterator InIt;
- pair<LiveVarSet::iterator, bool> result;
- bool changed = false;
- const BasicBlock *PredBBOfPhiArg;
-
- // for all all elements in InSet
- for( InIt = InSet->begin() ; InIt != InSet->end(); InIt++) {
- PredBBOfPhiArg = PhiArgMap[ *InIt ];
-
- // if this var is not a phi arg OR
- // it's a phi arg and the var went down from this BB
- if( !PredBBOfPhiArg || PredBBOfPhiArg == PredBB) {
- result = OutSet->insert( *InIt ); // insert to this set
- if( result.second == true) changed = true;
- }
- }
-
- return changed;
+bool BBLiveVar::setPropagate(ValueSet *OutSet, const ValueSet *InSet,
+ const BasicBlock *PredBB) {
+ bool Changed = false;
+
+ // merge all members of InSet into OutSet of the predecessor
+ for (ValueSet::const_iterator InIt = InSet->begin(), InE = InSet->end();
+ InIt != InE; ++InIt)
+ if ((OutSet->insert(*InIt)).second)
+ Changed = true;
+
+ //
+ //**** WARNING: The following code for handling dummy PHI machine
+ // instructions is untested. See explanation above.
+ //
+ // then merge all members of the EdgeInSet for the predecessor into the OutSet
+ const ValueSet& EdgeInSet = PredToEdgeInSetMap[PredBB];
+ for (ValueSet::const_iterator InIt = EdgeInSet.begin(), InE = EdgeInSet.end();
+ InIt != InE; ++InIt)
+ if ((OutSet->insert(*InIt)).second)
+ Changed = true;
+ //
+ //****
+
+ return Changed;
}
+//-----------------------------------------------------------------------------
+// propagates in set to OutSets of PREDECESSORs
+//-----------------------------------------------------------------------------
-// propogates in set to OutSets of PREDECESSORs
-
-bool BBLiveVar::applyFlowFunc(BBToBBLiveVarMapType LVMap)
-{
-
+bool BBLiveVar::applyFlowFunc(hash_map<const BasicBlock*,
+ BBLiveVar*> &BBLiveVarInfo) {
// IMPORTANT: caller should check whether inset changed
// (else no point in calling)
+
+ // If this BB changed any OutSets of preds whose POID is lower, than we need
+ // another iteration...
+ //
+ bool needAnotherIt = false;
- bool needAnotherIt= false; // did this BB change any OutSets of pred.s
- // whose POId is lower
-
-
- cfg::pred_const_iterator PredBBI = cfg::pred_begin(BaseBB);
-
- for( ; PredBBI != cfg::pred_end(BaseBB) ; PredBBI++) {
- assert( *PredBBI ); // assert that the predecessor is valid
- BBLiveVar *PredLVBB = LVMap[*PredBBI];
+ for (pred_const_iterator PI = pred_begin(&BB), PE = pred_end(&BB);
+ PI != PE ; ++PI) {
+ BBLiveVar *PredLVBB = BBLiveVarInfo[*PI];
- // do set union
- if( setPropagate( &(PredLVBB->OutSet), &InSet, *PredBBI ) == true) {
+ // do set union
+ if (setPropagate(&PredLVBB->OutSet, &InSet, *PI)) {
PredLVBB->OutSetChanged = true;
- // if the predec POId is lower than mine
- if( PredLVBB->getPOId() <= POId)
+ // if the predec POID is lower than mine
+ if (PredLVBB->getPOId() <= POID)
needAnotherIt = true;
}
-
} // for
return needAnotherIt;
-
}
-/* ----------------- Methods For Debugging (Printing) ----------------- */
+// ----------------- Methods For Debugging (Printing) -----------------
-void BBLiveVar::printAllSets() const
-{
- cout << " Defs: "; DefSet.printSet(); cout << endl;
- cout << " In: "; InSet.printSet(); cout << endl;
- cout << " Out: "; OutSet.printSet(); cout << endl;
+void BBLiveVar::printAllSets() const {
+ std::cerr << " Defs: "; printSet(DefSet); std::cerr << "\n";
+ std::cerr << " In: "; printSet(InSet); std::cerr << "\n";
+ std::cerr << " Out: "; printSet(OutSet); std::cerr << "\n";
}
-void BBLiveVar::printInOutSets() const
-{
- cout << " In: "; InSet.printSet(); cout << endl;
- cout << " Out: "; OutSet.printSet(); cout << endl;
+void BBLiveVar::printInOutSets() const {
+ std::cerr << " In: "; printSet(InSet); std::cerr << "\n";
+ std::cerr << " Out: "; printSet(OutSet); std::cerr << "\n";
}
-
-
-
+} // End llvm namespace
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