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
diff --git a/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp b/lib/Analysis/LiveVar/FunctionLiveVarInfo.cpp
index e981a86..636359d 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()
{
- // 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;
}
+
+
+ // 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 -------------------------------
+// ************************* 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 @@
}
-
-// 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 @@
-
+//-----------------------------------------------------------------------------
// performs live var anal for a method
+//-----------------------------------------------------------------------------
void MethodLiveVarInfo::analyze()
{
// Don't analyze the same method twice!
@@ -157,8 +183,8 @@
-
-/* 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 @@
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 @@
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 @@
}
+
+//-----------------------------------------------------------------------------
+// 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();