llvm-6502/include/llvm/CodeGen/LiveIntervalAnalysis.h
Evan Cheng 32dfbeada7 EXTRACT_SUBREG coalescing support. The coalescer now treats EXTRACT_SUBREG like
(almost) a register copy. However, it always coalesced to the register of the
RHS (the super-register). All uses of the result of a EXTRACT_SUBREG are sub-
register uses which adds subtle complications to load folding, spiller rewrite,
etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42899 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-12 08:50:34 +00:00

263 lines
9.2 KiB
C++

//===-- LiveIntervalAnalysis.h - Live Interval 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 file implements the LiveInterval analysis pass. Given some numbering of
// each the machine instructions (in this implemention depth-first order) an
// interval [i, j) is said to be a live interval for register v if there is no
// instruction with number j' > j such that v is live at j' abd there is no
// instruction with number i' < i such that v is live at i'. In this
// implementation intervals can have holes, i.e. an interval might look like
// [1,20), [50,65), [1000,1001).
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_LIVEINTERVAL_ANALYSIS_H
#define LLVM_CODEGEN_LIVEINTERVAL_ANALYSIS_H
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/LiveInterval.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Allocator.h"
namespace llvm {
class LiveVariables;
class MRegisterInfo;
class TargetInstrInfo;
class TargetRegisterClass;
class VirtRegMap;
class LiveIntervals : public MachineFunctionPass {
MachineFunction* mf_;
const TargetMachine* tm_;
const MRegisterInfo* mri_;
const TargetInstrInfo* tii_;
LiveVariables* lv_;
/// Special pool allocator for VNInfo's (LiveInterval val#).
///
BumpPtrAllocator VNInfoAllocator;
/// MBB2IdxMap - The indexes of the first and last instructions in the
/// specified basic block.
std::vector<std::pair<unsigned, unsigned> > MBB2IdxMap;
typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
Mi2IndexMap mi2iMap_;
typedef std::vector<MachineInstr*> Index2MiMap;
Index2MiMap i2miMap_;
typedef std::map<unsigned, LiveInterval> Reg2IntervalMap;
Reg2IntervalMap r2iMap_;
BitVector allocatableRegs_;
std::vector<MachineInstr*> ClonedMIs;
public:
static char ID; // Pass identification, replacement for typeid
LiveIntervals() : MachineFunctionPass((intptr_t)&ID) {}
struct InstrSlots {
enum {
LOAD = 0,
USE = 1,
DEF = 2,
STORE = 3,
NUM = 4
};
};
static unsigned getBaseIndex(unsigned index) {
return index - (index % InstrSlots::NUM);
}
static unsigned getBoundaryIndex(unsigned index) {
return getBaseIndex(index + InstrSlots::NUM - 1);
}
static unsigned getLoadIndex(unsigned index) {
return getBaseIndex(index) + InstrSlots::LOAD;
}
static unsigned getUseIndex(unsigned index) {
return getBaseIndex(index) + InstrSlots::USE;
}
static unsigned getDefIndex(unsigned index) {
return getBaseIndex(index) + InstrSlots::DEF;
}
static unsigned getStoreIndex(unsigned index) {
return getBaseIndex(index) + InstrSlots::STORE;
}
typedef Reg2IntervalMap::iterator iterator;
typedef Reg2IntervalMap::const_iterator const_iterator;
const_iterator begin() const { return r2iMap_.begin(); }
const_iterator end() const { return r2iMap_.end(); }
iterator begin() { return r2iMap_.begin(); }
iterator end() { return r2iMap_.end(); }
unsigned getNumIntervals() const { return r2iMap_.size(); }
LiveInterval &getInterval(unsigned reg) {
Reg2IntervalMap::iterator I = r2iMap_.find(reg);
assert(I != r2iMap_.end() && "Interval does not exist for register");
return I->second;
}
const LiveInterval &getInterval(unsigned reg) const {
Reg2IntervalMap::const_iterator I = r2iMap_.find(reg);
assert(I != r2iMap_.end() && "Interval does not exist for register");
return I->second;
}
bool hasInterval(unsigned reg) const {
return r2iMap_.count(reg);
}
/// getMBBStartIdx - Return the base index of the first instruction in the
/// specified MachineBasicBlock.
unsigned getMBBStartIdx(MachineBasicBlock *MBB) const {
return getMBBStartIdx(MBB->getNumber());
}
unsigned getMBBStartIdx(unsigned MBBNo) const {
assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
return MBB2IdxMap[MBBNo].first;
}
/// getMBBEndIdx - Return the store index of the last instruction in the
/// specified MachineBasicBlock.
unsigned getMBBEndIdx(MachineBasicBlock *MBB) const {
return getMBBEndIdx(MBB->getNumber());
}
unsigned getMBBEndIdx(unsigned MBBNo) const {
assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
return MBB2IdxMap[MBBNo].second;
}
/// getInstructionIndex - returns the base index of instr
unsigned getInstructionIndex(MachineInstr* instr) const {
Mi2IndexMap::const_iterator it = mi2iMap_.find(instr);
assert(it != mi2iMap_.end() && "Invalid instruction!");
return it->second;
}
/// getInstructionFromIndex - given an index in any slot of an
/// instruction return a pointer the instruction
MachineInstr* getInstructionFromIndex(unsigned index) const {
index /= InstrSlots::NUM; // convert index to vector index
assert(index < i2miMap_.size() &&
"index does not correspond to an instruction");
return i2miMap_[index];
}
// Interval creation
LiveInterval &getOrCreateInterval(unsigned reg) {
Reg2IntervalMap::iterator I = r2iMap_.find(reg);
if (I == r2iMap_.end())
I = r2iMap_.insert(I, std::make_pair(reg, createInterval(reg)));
return I->second;
}
std::vector<LiveInterval*> addIntervalsForSpills(const LiveInterval& i,
VirtRegMap& vrm, unsigned reg);
// Interval removal
void removeInterval(unsigned Reg) {
r2iMap_.erase(Reg);
}
/// isRemoved - returns true if the specified machine instr has been
/// removed.
bool isRemoved(MachineInstr* instr) const {
return !mi2iMap_.count(instr);
}
/// RemoveMachineInstrFromMaps - This marks the specified machine instr as
/// deleted.
void RemoveMachineInstrFromMaps(MachineInstr *MI) {
// remove index -> MachineInstr and
// MachineInstr -> index mappings
Mi2IndexMap::iterator mi2i = mi2iMap_.find(MI);
if (mi2i != mi2iMap_.end()) {
i2miMap_[mi2i->second/InstrSlots::NUM] = 0;
mi2iMap_.erase(mi2i);
}
}
BumpPtrAllocator& getVNInfoAllocator() { return VNInfoAllocator; }
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual void releaseMemory();
/// runOnMachineFunction - pass entry point
virtual bool runOnMachineFunction(MachineFunction&);
/// print - Implement the dump method.
virtual void print(std::ostream &O, const Module* = 0) const;
void print(std::ostream *O, const Module* M = 0) const {
if (O) print(*O, M);
}
private:
/// computeIntervals - Compute live intervals.
void computeIntervals();
/// handleRegisterDef - update intervals for a register def
/// (calls handlePhysicalRegisterDef and
/// handleVirtualRegisterDef)
void handleRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MI, unsigned MIIdx,
unsigned reg);
/// handleVirtualRegisterDef - update intervals for a virtual
/// register def
void handleVirtualRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MI,
unsigned MIIdx,
LiveInterval& interval);
/// handlePhysicalRegisterDef - update intervals for a physical register
/// def.
void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
MachineBasicBlock::iterator mi,
unsigned MIIdx,
LiveInterval &interval,
unsigned SrcReg);
/// handleLiveInRegister - Create interval for a livein register.
void handleLiveInRegister(MachineBasicBlock* mbb,
unsigned MIIdx,
LiveInterval &interval, bool isAlias = false);
/// isReMaterializable - Returns true if the definition MI of the specified
/// val# of the specified interval is re-materializable.
bool isReMaterializable(const LiveInterval &li, const VNInfo *ValNo,
MachineInstr *MI);
/// tryFoldMemoryOperand - Attempts to fold either a spill / restore from
/// slot / to reg or any rematerialized load into ith operand of specified
/// MI. If it is successul, MI is updated with the newly created MI and
/// returns true.
bool tryFoldMemoryOperand(MachineInstr* &MI, VirtRegMap &vrm,
MachineInstr *DefMI, unsigned index, unsigned i,
bool isSS, int slot, unsigned reg);
static LiveInterval createInterval(unsigned Reg);
void printRegName(unsigned reg) const;
};
} // End llvm namespace
#endif