-/* Title: MethodLiveVarInfo.h -*- C++ -*-
- 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
-
- It must be called like:
-
- MethodLiveVarInfo MLVI( Mehtod *); // initializes data structures
- MLVI.analyze(); // do the actural live variable anal
-
- After the analysis, getInSetOfBB or getOutSetofBB can be called to get
- live var info of a BB.
-
- The live var set before an instruction can be obtained in 2 ways:
-
- 1. Use the method getLiveVarSetAfterInst(Instruction *) to get the LV Info
- just after an instruction. (also exists getLiveVarSetBeforeInst(..))
-
- This function caluclates the LV info for a BB only once and caches that
- info. If the cache does not contain the LV info of the instruction, it
- calculates the LV info for the whole BB and caches them.
-
- Getting liveVar info this way uses more memory since, LV info should be
- cached. However, if you need LV info of nearly all the instructions of a
- BB, this is the best and simplest interfrace.
-
-
- 2. Use the OutSet and applyTranferFuncForInst(const Instruction *const Inst)
- declared in LiveVarSet and traverse the instructions of a basic block in
- reverse (using const_reverse_iterator in the BB class).
-
- This is the most memory efficient method if you need LV info for
- only several instructions in a BasicBlock. An example is given below:
-
-
- LiveVarSet LVSet; // this will be the set used to traverse through each BB
-
- // Initialize LVSet so that it is the same as OutSet of the BB
- LVSet.setUnion( LVI->getOutSetOfBB( *BBI ) );
-
- BasicBlock::InstListType::const_reverse_iterator
- InstIterator = InstListInBB.rbegin(); // get the rev iter for inst in BB
-
- // iterate over all the instructions in BB in reverse
- for( ; InstIterator != InstListInBB.rend(); InstIterator++) {
-
- //...... all code here which uses LVSet ........
-
- LVSet.applyTranferFuncForInst(*InstIterator);
-
- // Now LVSet contains live vars ABOVE the current instrution
- }
-
- See buildInterferenceGraph() for the above example.
-
-
-*/
-
-
-#ifndef METH_LIVE_VAR_INFO_H
-#define METH_LIVE_VAR_INFO_H
-
-// set DEBUG_LV for printing out debug messages
-// if DEBUG_LV is 1 normal output messages
-// if DEBUG_LV is 2 extensive debug info for each instr
-
-static const int DEBUG_LV = 0;
-
-#include "LiveVarSet.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/Instruction.h"
-#include "llvm/Method.h"
-
-#include "LiveVarMap.h"
-#include "BBLiveVar.h"
-
-
-class MethodLiveVarInfo
-{
- private:
-
- // Live var anal is done on this method - set by constructor
- const Method *const Meth;
-
- // A map betwn the BasicBlock and BBLiveVar
- BBToBBLiveVarMapType BB2BBLVMap;
-
+//===-- CodeGen/FunctionLiveVarInfo.h - LiveVar Analysis --------*- C++ -*-===//
+//
+// 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 the interface for live variable info of a function that is required
+// by any other part of the compiler
+//
+// After the analysis, getInSetOfBB or getOutSetofBB can be called to get
+// live var info of a BB.
+//
+// The live var set before an instruction can be obtained in 2 ways:
+//
+// 1. Use the method getLiveVarSetAfterInst(Instruction *) to get the LV Info
+// just after an instruction. (also exists getLiveVarSetBeforeInst(..))
+//
+// This function caluclates the LV info for a BB only once and caches that
+// info. If the cache does not contain the LV info of the instruction, it
+// calculates the LV info for the whole BB and caches them.
+//
+// Getting liveVar info this way uses more memory since, LV info should be
+// cached. However, if you need LV info of nearly all the instructions of a
+// BB, this is the best and simplest interfrace.
+//
+// 2. Use the OutSet and applyTranferFuncForInst(const Instruction *const Inst)
+// declared in LiveVarSet and traverse the instructions of a basic block in
+// reverse (using const_reverse_iterator in the BB class).
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FUNCTION_LIVE_VAR_INFO_H
+#define FUNCTION_LIVE_VAR_INFO_H
+
+#include "Support/hash_map"
+#include "llvm/Pass.h"
+#include "llvm/CodeGen/ValueSet.h"
+
+namespace llvm {
+
+class BBLiveVar;
+class MachineInstr;
+
+class FunctionLiveVarInfo : public FunctionPass {
// Machine Instr to LiveVarSet Map for providing LVset BEFORE each inst
- MInstToLiveVarSetMapType MInst2LVSetBI;
+ // These sets are owned by this map and will be freed in releaseMemory().
+ hash_map<const MachineInstr *, ValueSet *> MInst2LVSetBI;
- // Machine Instr to LiveVarSet Map for providing LVset AFTER each inst
- MInstToLiveVarSetMapType MInst2LVSetAI;
+ // Machine Instr to LiveVarSet Map for providing LVset AFTER each inst.
+ // These sets are just pointers to sets in MInst2LVSetBI or BBLiveVar.
+ hash_map<const MachineInstr *, ValueSet *> MInst2LVSetAI;
- // True if the analyze() method has been called. This is checked when
- // getInSet/OutSet is called to prevent calling those methods before analyze
- bool HasAnalyzed;
+ hash_map<const BasicBlock*, BBLiveVar*> BBLiveVarInfo;
+ // Stored Function that the data is computed with respect to
+ const Function *M;
// --------- private methods -----------------------------------------
// constructs BBLiveVars and init Def and In sets
- void constructBBs();
+ void constructBBs(const Function *F);
// do one backward pass over the CFG
- bool doSingleBackwardPass();
+ bool doSingleBackwardPass(const Function *F, unsigned int iter);
// calculates live var sets for instructions in a BB
- void calcLiveVarSetsForBB(const BasicBlock *const BB);
+ void calcLiveVarSetsForBB(const BasicBlock *BB);
+public:
+ // --------- Implement the FunctionPass interface ----------------------
- public:
- MethodLiveVarInfo(const Method *const Meth); // constructor
-
- ~MethodLiveVarInfo(); // destructor
+ // runOnFunction - Perform analysis, update internal data structures.
+ virtual bool runOnFunction(Function &F);
- // performs a liver var analysis of a single method
- void analyze();
+ // releaseMemory - After LiveVariable analysis has been used, forget!
+ virtual void releaseMemory();
- // gets OutSet of a BB
- inline const LiveVarSet *getOutSetOfBB( const BasicBlock *const BB) const {
- assert( HasAnalyzed && "call analyze() before calling this" );
- return ( (* (BB2BBLVMap.find(BB)) ).second ) ->getOutSet();
+ // getAnalysisUsage - Provide self!
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
}
- // gets InSet of a BB
- inline const LiveVarSet *getInSetOfBB( const BasicBlock *const BB) const {
- assert( HasAnalyzed && "call analyze() before calling this" );
- return ( (* (BB2BBLVMap.find(BB)) ).second )->getInSet();
- }
-
- // gets the Live var set BEFORE an instruction
- const LiveVarSet * getLiveVarSetBeforeMInst(const MachineInstr *const Inst,
- const BasicBlock *const CurBB);
+ // --------- Functions to access analysis results -------------------
- // gets the Live var set AFTER an instruction
- const LiveVarSet * getLiveVarSetAfterMInst(const MachineInstr *const MInst,
- const BasicBlock *const CurBB);
+ // get OutSet of a BB
+ const ValueSet &getOutSetOfBB(const BasicBlock *BB) const;
+ ValueSet &getOutSetOfBB(const BasicBlock *BB) ;
+ // get InSet of a BB
+ const ValueSet &getInSetOfBB(const BasicBlock *BB) const;
+ ValueSet &getInSetOfBB(const BasicBlock *BB) ;
+ // gets the Live var set BEFORE an instruction.
+ // if BB is specified and the live var set has not yet been computed,
+ // it will be computed on demand.
+ const ValueSet &getLiveVarSetBeforeMInst(const MachineInstr *MI,
+ const BasicBlock *BB = 0);
-
+ // gets the Live var set AFTER an instruction
+ // if BB is specified and the live var set has not yet been computed,
+ // it will be computed on demand.
+ const ValueSet &getLiveVarSetAfterMInst(const MachineInstr *MI,
+ const BasicBlock *BB = 0);
};
-
-
-
+} // End llvm namespace
#endif
-
-
-
-
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