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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp b/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp
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+++ b/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp
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+/* Title: ValueSet.h
+ Author: Ruchira Sasanka
+ Date: Jun 30, 01
+ Purpose:
+
+ This is the interface for live variable info of a method that is required by
+ any other part of the compiler.
+
+*/
+
+
+#include "llvm/Analysis/LiveVar/MethodLiveVarInfo.h"
+
+
+
+
+/************************** Constructor/Destructor ***************************/
+
+
+MethodLiveVarInfo::MethodLiveVarInfo(Method *const MethPtr) : BB2BBLVMap()
+{
+ Meth = MethPtr; // init BB2BBLVMap and records Method for future use
+}
+
+
+
+MethodLiveVarInfo:: ~MethodLiveVarInfo()
+{
+ BBToBBLiveVarMapType::iterator HMI = BB2BBLVMap.begin(); // hash map iterator
+
+ for( ; HMI != BB2BBLVMap.end() ; HMI ++ ) {
+ if( (*HMI).first ) // delete all LiveVarSets in BB2BBLVMap
+ delete (*HMI).second;
+ }
+}
+
+
+// -------------------------- support functions -------------------------------
+
+
+
+ // constructs BBLiveVars and init Def and In sets
+void MethodLiveVarInfo::constructBBs()
+{
+ unsigned int POId = 0; // Reverse Depth-first Order ID
+
+ cfg::po_const_iterator BBI = cfg::po_begin(Meth);
+
+ for( ; BBI != cfg::po_end(Meth) ; ++BBI, ++POId)
+ {
+
+ if(DEBUG_LV) cout << "-- For BB " << (*BBI)->getName() << ":" << endl ;
+
+ const BasicBlock *BB = *BBI; // get the current BB
+ BBLiveVar * LVBB = new BBLiveVar( BB, POId ); // create a new BBLiveVar
+
+ BB2BBLVMap[ BB ] = LVBB; // insert the pair to Map
+
+ LVBB->calcDefUseSets(); // calculates the def and in set
+
+ if(DEBUG_LV) LVBB->printAllSets();
+ //cout << "InSetChanged: " << LVBB->isInSetChanged() << endl;
+ }
+
+
+}
+
+ // do one backward pass over the CFG
+bool MethodLiveVarInfo::doSingleBackwardPass()
+{
+ bool ResultFlow, NeedAnotherIteration = false;
+
+ if(DEBUG_LV) cout << endl << "------- After Backward Pass --------" << endl;
+
+ cfg::po_const_iterator BBI = cfg::po_begin(Meth);
+
+ for( ; BBI != cfg::po_end(Meth) ; ++BBI)
+ {
+
+ BBLiveVar* LVBB = BB2BBLVMap[*BBI];
+ assert( LVBB );
+
+ if(DEBUG_LV) cout << "-- For BB " << (*BBI)->getName() << ":" << endl;
+ // cout << " (POId=" << LVBB->getPOId() << ")" << endl ;
+
+ ResultFlow = false;
+
+ if( LVBB->isOutSetChanged() )
+ LVBB->applyTransferFunc(); // apply the Transfer Func to calc the InSet
+ if( LVBB->isInSetChanged() )
+ ResultFlow = LVBB->applyFlowFunc( BB2BBLVMap ); // to calc Outsets of preds
+
+ if(DEBUG_LV) LVBB->printInOutSets();
+ //cout << "InChanged = " << LVBB->isInSetChanged()
+ //cout << " UpdatedBBwithLowerPOId = " << ResultFlow << endl;
+
+ if( ResultFlow ) NeedAnotherIteration = true;
+
+ }
+
+ return NeedAnotherIteration; // true if we need to reiterate over the CFG
+}
+
+
+
+
+
+void MethodLiveVarInfo::analyze() // performs live var anal for a method
+{
+ //cout << "In analyze . . ." << cout;
+
+ constructBBs(); // create and initialize all the BBLiveVars of the CFG
+
+ bool NeedAnotherIteration = false;
+ do {
+ NeedAnotherIteration = doSingleBackwardPass( ); // do one pass over CFG
+ } while (NeedAnotherIteration ); // repeat until we need more iterations
+}
+
+
+
+
+/* This function will give the LiveVar info for any instruction in a method. It
+ should be called after a call to analyze().
+
+ This function calucluates live var info for all the instructions in a BB,
+ when LVInfo for one inst is requested. Hence, this function is useful when
+ live var info is required for many (or all) instructions in a basic block
+ Also, the arguments to this method does not require specific iterators
+*/
+
+
+const LiveVarSet *
+MethodLiveVarInfo::getLiveVarSetBeforeInst(const Instruction *const Inst)
+{
+ // get the BB corresponding to the instruction
+ const BasicBlock *const CurBB = Inst->getParent();
+
+ const LiveVarSet *LVSet = Inst2LVSetMap[Inst];
+
+ if( LVSet ) return LVSet; // if found, just return the set
+
+ const BasicBlock::InstListType& InstListInBB = CurBB->getInstList();
+ BasicBlock::InstListType::const_reverse_iterator
+ InstItEnd= InstListInBB.rend() - 1; // InstItEnd is set to the first instr
+
+ // LVSet of first instr = InSet
+ Inst2LVSetMap[*InstItEnd] = getInSetOfBB( CurBB );
+
+ // if the first instruction is requested, just return the InSet
+ if( Inst == *InstItEnd) return Inst2LVSetMap[Inst];
+
+ // else calculate for all other instruction in the BB
+
+ BasicBlock::InstListType::const_reverse_iterator
+ InstIt= InstListInBB.rbegin(); // get the iterator for instructions in BB
+
+ LiveVarSet *CurSet = new LiveVarSet();
+ CurSet->setUnion( getOutSetOfBB( CurBB )); // LVSet now contains the OutSet
+
+ // calculate LVSet for all instructions in the basic block (except the first)
+ for( ; InstIt != InstItEnd ; InstIt++) {
+
+ CurSet->applyTranferFuncForInst( *InstIt ); // apply the transfer Func
+ LiveVarSet *NewSet = new LiveVarSet(); // create a new set and
+ NewSet->setUnion( CurSet ); // copy the set after T/F to it
+ Inst2LVSetMap[*InstIt] = NewSet; // record that in the map
+ }
+
+ return Inst2LVSetMap[Inst];
+}
+
+
+
+/*
+NOTES: delete all the LVBBs allocated by adding a destructor to the BB2BBLVMap???
+ use the dfo_iterator in the doSingleBackwardPass
+*/
+
+
+
+
+
+
+
+
+
+
+