mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-11-04 05:17:07 +00:00
81cd1e50ec
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@388 91177308-0d34-0410-b5e6-96231b3b80d8
157 lines
4.6 KiB
C++
157 lines
4.6 KiB
C++
/* Title: MethodLiveVarInfo.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
|
|
|
|
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 "llvm/CFG.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;
|
|
|
|
// Machine Instr to LiveVarSet Map for providing LVset BEFORE each inst
|
|
MInstToLiveVarSetMapType MInst2LVSetBI;
|
|
|
|
// Machine Instr to LiveVarSet Map for providing LVset AFTER each inst
|
|
MInstToLiveVarSetMapType 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;
|
|
|
|
|
|
// --------- private methods -----------------------------------------
|
|
|
|
// constructs BBLiveVars and init Def and In sets
|
|
void constructBBs();
|
|
|
|
// do one backward pass over the CFG
|
|
bool doSingleBackwardPass();
|
|
|
|
// calculates live var sets for instructions in a BB
|
|
void calcLiveVarSetsForBB(const BasicBlock *const BB);
|
|
|
|
|
|
public:
|
|
MethodLiveVarInfo(const Method *const Meth); // constructor
|
|
|
|
~MethodLiveVarInfo(); // destructor
|
|
|
|
// performs a liver var analysis of a single method
|
|
void analyze();
|
|
|
|
// 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();
|
|
}
|
|
|
|
// 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);
|
|
|
|
// gets the Live var set AFTER an instruction
|
|
const LiveVarSet * getLiveVarSetAfterMInst(const MachineInstr *const MInst,
|
|
const BasicBlock *const CurBB);
|
|
|
|
|
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|