Added more comments. Added code to destructor in MethodLiveVarInfo to delete

LiveVarSet caches.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1435 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 156 insertions, 42 deletions

diff --git a/lib/Analysis/LiveVar/BBLiveVar.cpp b/lib/Analysis/LiveVar/BBLiveVar.cpp
index 3f5d95d39e..d7e036b256 100644
--- a/lib/Analysis/LiveVar/BBLiveVar.cpp
+++ b/lib/Analysis/LiveVar/BBLiveVar.cpp
@@ -1,11 +1,12 @@
 #include "llvm/Analysis/LiveVar/BBLiveVar.h"
 #include "llvm/Analysis/LiveVar/MethodLiveVarInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
-#include "../../Target/Sparc/SparcInternals.h"  // TODO: FIXME!! Only for PHI defn
+#include "../../Target/Sparc/SparcInternals.h"  //  Only for PHI defn
 
 
-/********************* Implementation **************************************/
-
+//-----------------------------------------------------------------------------
+// Constructor
+//-----------------------------------------------------------------------------
 BBLiveVar::BBLiveVar( const BasicBlock *const  baseBB, unsigned int RdfoId) 
                       : BaseBB(baseBB), DefSet(),  InSet(), 
 			OutSet(), PhiArgMap() {  
@@ -14,10 +15,13 @@ BBLiveVar::BBLiveVar( const BasicBlock *const  baseBB, unsigned int RdfoId)
     POId = RdfoId;
 }
 
+
+//-----------------------------------------------------------------------------
 // caluculates 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()  
 {
@@ -56,7 +60,7 @@ void BBLiveVar::calcDefUseSets()
 
  
     // iterate over  MI operands to find uses
-    for (MachineInstr::val_const_op_iterator OpI(MInst); !OpI.done() ;  ++OpI) {
+    for (MachineInstr::val_const_op_iterator OpI(MInst); !OpI.done() ; ++OpI) {
       const Value *Op = *OpI;
 
       if ( ((Op)->getType())->isLabelType() )    
@@ -106,10 +110,12 @@ void BBLiveVar::calcDefUseSets()
 
   } // for all machine instructions
 } 
-	
 
-// To add an operand wichi is a def
 
+	
+//-----------------------------------------------------------------------------
+// To add an operand which is a def
+//-----------------------------------------------------------------------------
 void  BBLiveVar::addDef(const Value *Op) 
 {
   DefSet.add( Op );     // operand is a def - so add to def set
@@ -121,8 +127,10 @@ void  BBLiveVar::addDef(const Value *Op)
   }
 }
 
-// To add an operand which is a use
 
+//-----------------------------------------------------------------------------
+// To add an operand which is a use
+//-----------------------------------------------------------------------------
 void  BBLiveVar::addUse(const Value *Op) 
 {
   InSet.add( Op );      // An operand is a use - so add to use set
@@ -136,6 +144,10 @@ void  BBLiveVar::addUse(const Value *Op)
 }
 
 
+//-----------------------------------------------------------------------------
+// Applies the transfer function to a basic block to produce the InSet using
+// the outset. 
+//-----------------------------------------------------------------------------
 
 bool BBLiveVar::applyTransferFunc() // calculates the InSet in terms of OutSet 
 {
@@ -153,8 +165,9 @@ bool BBLiveVar::applyTransferFunc() // calculates the InSet in terms of OutSet
 }
 
 
-
+//-----------------------------------------------------------------------------
 // calculates Out set using In sets of the predecessors
+//-----------------------------------------------------------------------------
 bool BBLiveVar::setPropagate( LiveVarSet *const OutSet, 
 			      const LiveVarSet *const InSet, 
 			      const BasicBlock *const PredBB) {
@@ -180,9 +193,9 @@ bool BBLiveVar::setPropagate( LiveVarSet *const OutSet,
 } 
 
 
-
+//-----------------------------------------------------------------------------
 // propogates in set to OutSets of PREDECESSORs
-
+//-----------------------------------------------------------------------------
 bool BBLiveVar::applyFlowFunc(BBToBBLiveVarMapType LVMap) 
 {
 
diff --git a/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp b/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp
index e981a86642..636359d1d0 100644
--- a/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp
+++ b/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp
@@ -14,7 +14,7 @@
 #include "Support/PostOrderIterator.h"
 
 
-/************************** Constructor/Destructor ***************************/
+//************************** Constructor/Destructor ***************************
 
 
 MethodLiveVarInfo::MethodLiveVarInfo(const Method *const M) : Meth(M),  
@@ -28,21 +28,45 @@ MethodLiveVarInfo::MethodLiveVarInfo(const Method *const M) : Meth(M),
 
 MethodLiveVarInfo:: ~MethodLiveVarInfo()
 {
-  // hash map iterator
+  // First delete all BBLiveVar objects created in constructBBs(). A new object
+  // of type  BBLiveVa is created for every BasicBlock in the method
+
+  // hash map iterator for BB2BBLVMap
+  //
   BBToBBLiveVarMapType::iterator HMI = BB2BBLVMap.begin(); 
 
   for( ; HMI != BB2BBLVMap.end() ; HMI ++ ) {  
-    if( (*HMI).first )                  // delete all LiveVarSets in BB2BBLVMap
+    if( (*HMI).first )                // delete all BBLiveVar in BB2BBLVMap
       delete (*HMI).second;
    }
-}
 
 
-// -------------------------- support functions -------------------------------
+  // Then delete all objects of type LiveVarSet created in calcLiveVarSetsForBB
+  // and entered into  MInst2LVSetBI and  MInst2LVSetAI (these are caches
+  // to return LiveVarSet's before/after a machine instruction quickly). It
+  // is sufficient to free up all LiveVarSet using only one cache since 
+  // both caches refer to the same sets
+
+  // hash map iterator for MInst2LVSetBI
+  //
+  MInstToLiveVarSetMapType::iterator MI =  MInst2LVSetBI.begin(); 
+
+  for( ; MI !=  MInst2LVSetBI.end() ; MI ++ ) {  
+    if( (*MI).first )              // delete all LiveVarSets in  MInst2LVSetBI
+      delete (*MI).second;
+   }
+
+
+}
+
 
+// ************************* support functions ********************************
 
 
+//-----------------------------------------------------------------------------
 // constructs BBLiveVars and init Def and In sets
+//-----------------------------------------------------------------------------
+
 void MethodLiveVarInfo::constructBBs()   
 {
   unsigned int POId = 0;                // Reverse Depth-first Order ID
@@ -85,8 +109,9 @@ void MethodLiveVarInfo::constructBBs()
 }
 
 
-
-// do one backward pass over the CFG
+//-----------------------------------------------------------------------------
+// do one backward pass over the CFG (for iterative analysis)
+//-----------------------------------------------------------------------------
 bool MethodLiveVarInfo::doSingleBackwardPass()  
 {
   bool ResultFlow, NeedAnotherIteration = false;
@@ -127,8 +152,9 @@ bool MethodLiveVarInfo::doSingleBackwardPass()
 
 
 
-
+//-----------------------------------------------------------------------------
 // performs live var anal for a method
+//-----------------------------------------------------------------------------
 void MethodLiveVarInfo::analyze()        
 {
   // Don't analyze the same method twice!
@@ -157,8 +183,8 @@ void MethodLiveVarInfo::analyze()
 
 
 
-
-/* Thsese functions will give the LiveVar info for any machine instruction in
+//-----------------------------------------------------------------------------
+/* Following functions will give the LiveVar info for any machine instr in
    a method. It should be called after a call to analyze().
 
    Thsese functions calucluates live var info for all the machine instrs in a 
@@ -167,8 +193,11 @@ void MethodLiveVarInfo::analyze()
    block. Also, the arguments to this method does not require specific 
    iterators.
 */
+//-----------------------------------------------------------------------------
 
-
+//-----------------------------------------------------------------------------
+// Gives live variable information before a machine instruction
+//-----------------------------------------------------------------------------
 const LiveVarSet * 
 MethodLiveVarInfo::getLiveVarSetBeforeMInst(const MachineInstr *const MInst,
 					    const BasicBlock *const CurBB) 
@@ -178,12 +207,21 @@ MethodLiveVarInfo::getLiveVarSetBeforeMInst(const MachineInstr *const MInst,
   if( LVSet  ) return LVSet;              // if found, just return the set
   else { 
     calcLiveVarSetsForBB( CurBB );        // else, calc for all instrs in BB
+
+    /*if(  ! MInst2LVSetBI[ MInst ] ) {
+      cerr << "\nFor BB "; printValue( CurBB);
+      cerr << "\nRequested LVSet for inst: " << *MInst;
+      }*/
+
     assert( MInst2LVSetBI[ MInst ] );
     return  MInst2LVSetBI[ MInst ];
   }
 }
 
 
+//-----------------------------------------------------------------------------
+// Gives live variable information after a machine instruction
+//-----------------------------------------------------------------------------
 const LiveVarSet * 
 MethodLiveVarInfo::getLiveVarSetAfterMInst(const MachineInstr *const MInst,
 					    const BasicBlock *const CurBB) 
@@ -199,6 +237,12 @@ MethodLiveVarInfo::getLiveVarSetAfterMInst(const MachineInstr *const MInst,
 }
 
 
+
+//-----------------------------------------------------------------------------
+// This method calculates the live variable information for all the 
+// instructions in a basic block and enter the newly constructed live
+// variable sets into a the caches ( MInst2LVSetAI,  MInst2LVSetBI)
+//-----------------------------------------------------------------------------
 void MethodLiveVarInfo::calcLiveVarSetsForBB(const BasicBlock *const BB)
 {
   const MachineCodeForBasicBlock& MIVec = BB->getMachineInstrVec();
diff --git a/lib/Target/SparcV9/LiveVar/BBLiveVar.cpp b/lib/Target/SparcV9/LiveVar/BBLiveVar.cpp
index 3f5d95d39e..d7e036b256 100644
--- a/lib/Target/SparcV9/LiveVar/BBLiveVar.cpp
+++ b/lib/Target/SparcV9/LiveVar/BBLiveVar.cpp
@@ -1,11 +1,12 @@
 #include "llvm/Analysis/LiveVar/BBLiveVar.h"
 #include "llvm/Analysis/LiveVar/MethodLiveVarInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
-#include "../../Target/Sparc/SparcInternals.h"  // TODO: FIXME!! Only for PHI defn
+#include "../../Target/Sparc/SparcInternals.h"  //  Only for PHI defn
 
 
-/********************* Implementation **************************************/
-
+//-----------------------------------------------------------------------------
+// Constructor
+//-----------------------------------------------------------------------------
 BBLiveVar::BBLiveVar( const BasicBlock *const  baseBB, unsigned int RdfoId) 
                       : BaseBB(baseBB), DefSet(),  InSet(), 
 			OutSet(), PhiArgMap() {  
@@ -14,10 +15,13 @@ BBLiveVar::BBLiveVar( const BasicBlock *const  baseBB, unsigned int RdfoId)
     POId = RdfoId;
 }
 
+
+//-----------------------------------------------------------------------------
 // caluculates 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()  
 {
@@ -56,7 +60,7 @@ void BBLiveVar::calcDefUseSets()
 
  
     // iterate over  MI operands to find uses
-    for (MachineInstr::val_const_op_iterator OpI(MInst); !OpI.done() ;  ++OpI) {
+    for (MachineInstr::val_const_op_iterator OpI(MInst); !OpI.done() ; ++OpI) {
       const Value *Op = *OpI;
 
       if ( ((Op)->getType())->isLabelType() )    
@@ -106,10 +110,12 @@ void BBLiveVar::calcDefUseSets()
 
   } // for all machine instructions
 } 
-	
 
-// To add an operand wichi is a def
 
+	
+//-----------------------------------------------------------------------------
+// To add an operand which is a def
+//-----------------------------------------------------------------------------
 void  BBLiveVar::addDef(const Value *Op) 
 {
   DefSet.add( Op );     // operand is a def - so add to def set
@@ -121,8 +127,10 @@ void  BBLiveVar::addDef(const Value *Op)
   }
 }
 
-// To add an operand which is a use
 
+//-----------------------------------------------------------------------------
+// To add an operand which is a use
+//-----------------------------------------------------------------------------
 void  BBLiveVar::addUse(const Value *Op) 
 {
   InSet.add( Op );      // An operand is a use - so add to use set
@@ -136,6 +144,10 @@ void  BBLiveVar::addUse(const Value *Op)
 }
 
 
+//-----------------------------------------------------------------------------
+// Applies the transfer function to a basic block to produce the InSet using
+// the outset. 
+//-----------------------------------------------------------------------------
 
 bool BBLiveVar::applyTransferFunc() // calculates the InSet in terms of OutSet 
 {
@@ -153,8 +165,9 @@ bool BBLiveVar::applyTransferFunc() // calculates the InSet in terms of OutSet
 }
 
 
-
+//-----------------------------------------------------------------------------
 // calculates Out set using In sets of the predecessors
+//-----------------------------------------------------------------------------
 bool BBLiveVar::setPropagate( LiveVarSet *const OutSet, 
 			      const LiveVarSet *const InSet, 
 			      const BasicBlock *const PredBB) {
@@ -180,9 +193,9 @@ bool BBLiveVar::setPropagate( LiveVarSet *const OutSet,
 } 
 
 
-
+//-----------------------------------------------------------------------------
 // propogates in set to OutSets of PREDECESSORs
-
+//-----------------------------------------------------------------------------
 bool BBLiveVar::applyFlowFunc(BBToBBLiveVarMapType LVMap) 
 {
 
diff --git a/lib/Target/SparcV9/LiveVar/FunctionLiveVarInfo.cpp b/lib/Target/SparcV9/LiveVar/FunctionLiveVarInfo.cpp
index e981a86642..636359d1d0 100644
--- a/lib/Target/SparcV9/LiveVar/FunctionLiveVarInfo.cpp
+++ b/lib/Target/SparcV9/LiveVar/FunctionLiveVarInfo.cpp
@@ -14,7 +14,7 @@
 #include "Support/PostOrderIterator.h"
 
 
-/************************** Constructor/Destructor ***************************/
+//************************** Constructor/Destructor ***************************
 
 
 MethodLiveVarInfo::MethodLiveVarInfo(const Method *const M) : Meth(M),  
@@ -28,21 +28,45 @@ MethodLiveVarInfo::MethodLiveVarInfo(const Method *const M) : Meth(M),
 
 MethodLiveVarInfo:: ~MethodLiveVarInfo()
 {
-  // hash map iterator
+  // First delete all BBLiveVar objects created in constructBBs(). A new object
+  // of type  BBLiveVa is created for every BasicBlock in the method
+
+  // hash map iterator for BB2BBLVMap
+  //
   BBToBBLiveVarMapType::iterator HMI = BB2BBLVMap.begin(); 
 
   for( ; HMI != BB2BBLVMap.end() ; HMI ++ ) {  
-    if( (*HMI).first )                  // delete all LiveVarSets in BB2BBLVMap
+    if( (*HMI).first )                // delete all BBLiveVar in BB2BBLVMap
       delete (*HMI).second;
    }
-}
 
 
-// -------------------------- support functions -------------------------------
+  // Then delete all objects of type LiveVarSet created in calcLiveVarSetsForBB
+  // and entered into  MInst2LVSetBI and  MInst2LVSetAI (these are caches
+  // to return LiveVarSet's before/after a machine instruction quickly). It
+  // is sufficient to free up all LiveVarSet using only one cache since 
+  // both caches refer to the same sets
+
+  // hash map iterator for MInst2LVSetBI
+  //
+  MInstToLiveVarSetMapType::iterator MI =  MInst2LVSetBI.begin(); 
+
+  for( ; MI !=  MInst2LVSetBI.end() ; MI ++ ) {  
+    if( (*MI).first )              // delete all LiveVarSets in  MInst2LVSetBI
+      delete (*MI).second;
+   }
+
+
+}
+
 
+// ************************* support functions ********************************
 
 
+//-----------------------------------------------------------------------------
 // constructs BBLiveVars and init Def and In sets
+//-----------------------------------------------------------------------------
+
 void MethodLiveVarInfo::constructBBs()   
 {
   unsigned int POId = 0;                // Reverse Depth-first Order ID
@@ -85,8 +109,9 @@ void MethodLiveVarInfo::constructBBs()
 }
 
 
-
-// do one backward pass over the CFG
+//-----------------------------------------------------------------------------
+// do one backward pass over the CFG (for iterative analysis)
+//-----------------------------------------------------------------------------
 bool MethodLiveVarInfo::doSingleBackwardPass()  
 {
   bool ResultFlow, NeedAnotherIteration = false;
@@ -127,8 +152,9 @@ bool MethodLiveVarInfo::doSingleBackwardPass()
 
 
 
-
+//-----------------------------------------------------------------------------
 // performs live var anal for a method
+//-----------------------------------------------------------------------------
 void MethodLiveVarInfo::analyze()        
 {
   // Don't analyze the same method twice!
@@ -157,8 +183,8 @@ void MethodLiveVarInfo::analyze()
 
 
 
-
-/* Thsese functions will give the LiveVar info for any machine instruction in
+//-----------------------------------------------------------------------------
+/* Following functions will give the LiveVar info for any machine instr in
    a method. It should be called after a call to analyze().
 
    Thsese functions calucluates live var info for all the machine instrs in a 
@@ -167,8 +193,11 @@ void MethodLiveVarInfo::analyze()
    block. Also, the arguments to this method does not require specific 
    iterators.
 */
+//-----------------------------------------------------------------------------
 
-
+//-----------------------------------------------------------------------------
+// Gives live variable information before a machine instruction
+//-----------------------------------------------------------------------------
 const LiveVarSet * 
 MethodLiveVarInfo::getLiveVarSetBeforeMInst(const MachineInstr *const MInst,
 					    const BasicBlock *const CurBB) 
@@ -178,12 +207,21 @@ MethodLiveVarInfo::getLiveVarSetBeforeMInst(const MachineInstr *const MInst,
   if( LVSet  ) return LVSet;              // if found, just return the set
   else { 
     calcLiveVarSetsForBB( CurBB );        // else, calc for all instrs in BB
+
+    /*if(  ! MInst2LVSetBI[ MInst ] ) {
+      cerr << "\nFor BB "; printValue( CurBB);
+      cerr << "\nRequested LVSet for inst: " << *MInst;
+      }*/
+
     assert( MInst2LVSetBI[ MInst ] );
     return  MInst2LVSetBI[ MInst ];
   }
 }
 
 
+//-----------------------------------------------------------------------------
+// Gives live variable information after a machine instruction
+//-----------------------------------------------------------------------------
 const LiveVarSet * 
 MethodLiveVarInfo::getLiveVarSetAfterMInst(const MachineInstr *const MInst,
 					    const BasicBlock *const CurBB) 
@@ -199,6 +237,12 @@ MethodLiveVarInfo::getLiveVarSetAfterMInst(const MachineInstr *const MInst,
 }
 
 
+
+//-----------------------------------------------------------------------------
+// This method calculates the live variable information for all the 
+// instructions in a basic block and enter the newly constructed live
+// variable sets into a the caches ( MInst2LVSetAI,  MInst2LVSetBI)
+//-----------------------------------------------------------------------------
 void MethodLiveVarInfo::calcLiveVarSetsForBB(const BasicBlock *const BB)
 {
   const MachineCodeForBasicBlock& MIVec = BB->getMachineInstrVec();