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llvm-6502/include/llvm/CodeGen/SlotIndexes.h
Jakob Stoklund Olesen b4ddedce59 Extract parts of RAGreedy::splitAroundRegion as SplitKit methods. 
This gets rid of some of the gory splitting details in RAGreedy and
makes them available to future SplitKit clients.

Slightly generalize the functionality to support multi-way splitting.
Specifically, SplitEditor::splitLiveThroughBlock() supports switching
between different register intervals in a block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135307 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-15 21:47:57 +00:00

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//===- llvm/CodeGen/SlotIndexes.h - Slot indexes representation -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements SlotIndex and related classes. The purpuse of SlotIndex
// is to describe a position at which a register can become live, or cease to
// be live.
//
// SlotIndex is mostly a proxy for entries of the SlotIndexList, a class which
// is held is LiveIntervals and provides the real numbering. This allows
// LiveIntervals to perform largely transparent renumbering.
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SLOTINDEXES_H
#define LLVM_CODEGEN_SLOTINDEXES_H
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/Allocator.h"
namespace llvm {
/// This class represents an entry in the slot index list held in the
/// SlotIndexes pass. It should not be used directly. See the
/// SlotIndex & SlotIndexes classes for the public interface to this
/// information.
class IndexListEntry {
IndexListEntry *next, *prev;
MachineInstr *mi;
unsigned index;
public:
IndexListEntry(MachineInstr *mi, unsigned index) : mi(mi), index(index) {}
MachineInstr* getInstr() const { return mi; }
void setInstr(MachineInstr *mi) {
this->mi = mi;
}
unsigned getIndex() const { return index; }
void setIndex(unsigned index) {
this->index = index;
}
IndexListEntry* getNext() { return next; }
const IndexListEntry* getNext() const { return next; }
void setNext(IndexListEntry *next) {
this->next = next;
}
IndexListEntry* getPrev() { return prev; }
const IndexListEntry* getPrev() const { return prev; }
void setPrev(IndexListEntry *prev) {
this->prev = prev;
}
};
// Specialize PointerLikeTypeTraits for IndexListEntry.
template <>
class PointerLikeTypeTraits<IndexListEntry*> {
public:
static inline void* getAsVoidPointer(IndexListEntry *p) {
return p;
}
static inline IndexListEntry* getFromVoidPointer(void *p) {
return static_cast<IndexListEntry*>(p);
}
enum { NumLowBitsAvailable = 3 };
};
/// SlotIndex - An opaque wrapper around machine indexes.
class SlotIndex {
friend class SlotIndexes;
friend struct DenseMapInfo<SlotIndex>;
enum Slot { LOAD, USE, DEF, STORE, NUM };
PointerIntPair<IndexListEntry*, 2, unsigned> lie;
SlotIndex(IndexListEntry *entry, unsigned slot)
: lie(entry, slot) {}
IndexListEntry& entry() const {
assert(isValid() && "Attempt to compare reserved index.");
return *lie.getPointer();
}
int getIndex() const {
return entry().getIndex() | getSlot();
}
/// Returns the slot for this SlotIndex.
Slot getSlot() const {
return static_cast<Slot>(lie.getInt());
}
static inline unsigned getHashValue(const SlotIndex &v) {
void *ptrVal = v.lie.getOpaqueValue();
return (unsigned((intptr_t)ptrVal)) ^ (unsigned((intptr_t)ptrVal) >> 9);
}
public:
enum {
/// The default distance between instructions as returned by distance().
/// This may vary as instructions are inserted and removed.
InstrDist = 4*NUM
};
static inline SlotIndex getEmptyKey() {
return SlotIndex(0, 1);
}
static inline SlotIndex getTombstoneKey() {
return SlotIndex(0, 2);
}
/// Construct an invalid index.
SlotIndex() : lie(0, 0) {}
// Construct a new slot index from the given one, and set the slot.
SlotIndex(const SlotIndex &li, Slot s)
: lie(&li.entry(), unsigned(s)) {
assert(lie.getPointer() != 0 &&
"Attempt to construct index with 0 pointer.");
}
/// Returns true if this is a valid index. Invalid indicies do
/// not point into an index table, and cannot be compared.
bool isValid() const {
return lie.getPointer();
}
/// Return true for a valid index.
operator bool() const { return isValid(); }
/// Print this index to the given raw_ostream.
void print(raw_ostream &os) const;
/// Dump this index to stderr.
void dump() const;
/// Compare two SlotIndex objects for equality.
bool operator==(SlotIndex other) const {
return lie == other.lie;
}
/// Compare two SlotIndex objects for inequality.
bool operator!=(SlotIndex other) const {
return lie != other.lie;
}
/// Compare two SlotIndex objects. Return true if the first index
/// is strictly lower than the second.
bool operator<(SlotIndex other) const {
return getIndex() < other.getIndex();
}
/// Compare two SlotIndex objects. Return true if the first index
/// is lower than, or equal to, the second.
bool operator<=(SlotIndex other) const {
return getIndex() <= other.getIndex();
}
/// Compare two SlotIndex objects. Return true if the first index
/// is greater than the second.
bool operator>(SlotIndex other) const {
return getIndex() > other.getIndex();
}
/// Compare two SlotIndex objects. Return true if the first index
/// is greater than, or equal to, the second.
bool operator>=(SlotIndex other) const {
return getIndex() >= other.getIndex();
}
/// isSameInstr - Return true if A and B refer to the same instruction.
static bool isSameInstr(SlotIndex A, SlotIndex B) {
return A.lie.getPointer() == B.lie.getPointer();
}
/// Return the distance from this index to the given one.
int distance(SlotIndex other) const {
return other.getIndex() - getIndex();
}
/// isLoad - Return true if this is a LOAD slot.
bool isLoad() const {
return getSlot() == LOAD;
}
/// isDef - Return true if this is a DEF slot.
bool isDef() const {
return getSlot() == DEF;
}
/// isUse - Return true if this is a USE slot.
bool isUse() const {
return getSlot() == USE;
}
/// isStore - Return true if this is a STORE slot.
bool isStore() const {
return getSlot() == STORE;
}
/// Returns the base index for associated with this index. The base index
/// is the one associated with the LOAD slot for the instruction pointed to
/// by this index.
SlotIndex getBaseIndex() const {
return getLoadIndex();
}
/// Returns the boundary index for associated with this index. The boundary
/// index is the one associated with the LOAD slot for the instruction
/// pointed to by this index.
SlotIndex getBoundaryIndex() const {
return getStoreIndex();
}
/// Returns the index of the LOAD slot for the instruction pointed to by
/// this index.
SlotIndex getLoadIndex() const {
return SlotIndex(&entry(), SlotIndex::LOAD);
}
/// Returns the index of the USE slot for the instruction pointed to by
/// this index.
SlotIndex getUseIndex() const {
return SlotIndex(&entry(), SlotIndex::USE);
}
/// Returns the index of the DEF slot for the instruction pointed to by
/// this index.
SlotIndex getDefIndex() const {
return SlotIndex(&entry(), SlotIndex::DEF);
}
/// Returns the index of the STORE slot for the instruction pointed to by
/// this index.
SlotIndex getStoreIndex() const {
return SlotIndex(&entry(), SlotIndex::STORE);
}
/// Returns the next slot in the index list. This could be either the
/// next slot for the instruction pointed to by this index or, if this
/// index is a STORE, the first slot for the next instruction.
/// WARNING: This method is considerably more expensive than the methods
/// that return specific slots (getUseIndex(), etc). If you can - please
/// use one of those methods.
SlotIndex getNextSlot() const {
Slot s = getSlot();
if (s == SlotIndex::STORE) {
return SlotIndex(entry().getNext(), SlotIndex::LOAD);
}
return SlotIndex(&entry(), s + 1);
}
/// Returns the next index. This is the index corresponding to the this
/// index's slot, but for the next instruction.
SlotIndex getNextIndex() const {
return SlotIndex(entry().getNext(), getSlot());
}
/// Returns the previous slot in the index list. This could be either the
/// previous slot for the instruction pointed to by this index or, if this
/// index is a LOAD, the last slot for the previous instruction.
/// WARNING: This method is considerably more expensive than the methods
/// that return specific slots (getUseIndex(), etc). If you can - please
/// use one of those methods.
SlotIndex getPrevSlot() const {
Slot s = getSlot();
if (s == SlotIndex::LOAD) {
return SlotIndex(entry().getPrev(), SlotIndex::STORE);
}
return SlotIndex(&entry(), s - 1);
}
/// Returns the previous index. This is the index corresponding to this
/// index's slot, but for the previous instruction.
SlotIndex getPrevIndex() const {
return SlotIndex(entry().getPrev(), getSlot());
}
};
/// DenseMapInfo specialization for SlotIndex.
template <>
struct DenseMapInfo<SlotIndex> {
static inline SlotIndex getEmptyKey() {
return SlotIndex::getEmptyKey();
}
static inline SlotIndex getTombstoneKey() {
return SlotIndex::getTombstoneKey();
}
static inline unsigned getHashValue(const SlotIndex &v) {
return SlotIndex::getHashValue(v);
}
static inline bool isEqual(const SlotIndex &LHS, const SlotIndex &RHS) {
return (LHS == RHS);
}
};
template <> struct isPodLike<SlotIndex> { static const bool value = true; };
inline raw_ostream& operator<<(raw_ostream &os, SlotIndex li) {
li.print(os);
return os;
}
typedef std::pair<SlotIndex, MachineBasicBlock*> IdxMBBPair;
inline bool operator<(SlotIndex V, const IdxMBBPair &IM) {
return V < IM.first;
}
inline bool operator<(const IdxMBBPair &IM, SlotIndex V) {
return IM.first < V;
}
struct Idx2MBBCompare {
bool operator()(const IdxMBBPair &LHS, const IdxMBBPair &RHS) const {
return LHS.first < RHS.first;
}
};
/// SlotIndexes pass.
///
/// This pass assigns indexes to each instruction.
class SlotIndexes : public MachineFunctionPass {
private:
MachineFunction *mf;
IndexListEntry *indexListHead;
unsigned functionSize;
typedef DenseMap<const MachineInstr*, SlotIndex> Mi2IndexMap;
Mi2IndexMap mi2iMap;
/// MBBRanges - Map MBB number to (start, stop) indexes.
SmallVector<std::pair<SlotIndex, SlotIndex>, 8> MBBRanges;
/// Idx2MBBMap - Sorted list of pairs of index of first instruction
/// and MBB id.
SmallVector<IdxMBBPair, 8> idx2MBBMap;
// IndexListEntry allocator.
BumpPtrAllocator ileAllocator;
IndexListEntry* createEntry(MachineInstr *mi, unsigned index) {
IndexListEntry *entry =
static_cast<IndexListEntry*>(
ileAllocator.Allocate(sizeof(IndexListEntry),
alignOf<IndexListEntry>()));
new (entry) IndexListEntry(mi, index);
return entry;
}
void initList() {
assert(indexListHead == 0 && "Zero entry non-null at initialisation.");
indexListHead = createEntry(0, ~0U);
indexListHead->setNext(0);
indexListHead->setPrev(indexListHead);
}
void clearList() {
indexListHead = 0;
ileAllocator.Reset();
}
IndexListEntry* getTail() {
assert(indexListHead != 0 && "Call to getTail on uninitialized list.");
return indexListHead->getPrev();
}
const IndexListEntry* getTail() const {
assert(indexListHead != 0 && "Call to getTail on uninitialized list.");
return indexListHead->getPrev();
}
// Returns true if the index list is empty.
bool empty() const { return (indexListHead == getTail()); }
IndexListEntry* front() {
assert(!empty() && "front() called on empty index list.");
return indexListHead;
}
const IndexListEntry* front() const {
assert(!empty() && "front() called on empty index list.");
return indexListHead;
}
IndexListEntry* back() {
assert(!empty() && "back() called on empty index list.");
return getTail()->getPrev();
}
const IndexListEntry* back() const {
assert(!empty() && "back() called on empty index list.");
return getTail()->getPrev();
}
/// Insert a new entry before itr.
void insert(IndexListEntry *itr, IndexListEntry *val) {
assert(itr != 0 && "itr should not be null.");
IndexListEntry *prev = itr->getPrev();
val->setNext(itr);
val->setPrev(prev);
if (itr != indexListHead) {
prev->setNext(val);
}
else {
indexListHead = val;
}
itr->setPrev(val);
}
/// Push a new entry on to the end of the list.
void push_back(IndexListEntry *val) {
insert(getTail(), val);
}
/// Renumber locally after inserting newEntry.
void renumberIndexes(IndexListEntry *newEntry);
public:
static char ID;
SlotIndexes() : MachineFunctionPass(ID), indexListHead(0) {
initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
}
virtual void getAnalysisUsage(AnalysisUsage &au) const;
virtual void releaseMemory();
virtual bool runOnMachineFunction(MachineFunction &fn);
/// Dump the indexes.
void dump() const;
/// Renumber the index list, providing space for new instructions.
void renumberIndexes();
/// Returns the zero index for this analysis.
SlotIndex getZeroIndex() {
assert(front()->getIndex() == 0 && "First index is not 0?");
return SlotIndex(front(), 0);
}
/// Returns the base index of the last slot in this analysis.
SlotIndex getLastIndex() {
return SlotIndex(back(), 0);
}
/// Returns the invalid index marker for this analysis.
SlotIndex getInvalidIndex() {
return getZeroIndex();
}
/// Returns the distance between the highest and lowest indexes allocated
/// so far.
unsigned getIndexesLength() const {
assert(front()->getIndex() == 0 &&
"Initial index isn't zero?");
return back()->getIndex();
}
/// Returns the number of instructions in the function.
unsigned getFunctionSize() const {
return functionSize;
}
/// Returns true if the given machine instr is mapped to an index,
/// otherwise returns false.
bool hasIndex(const MachineInstr *instr) const {
return (mi2iMap.find(instr) != mi2iMap.end());
}
/// Returns the base index for the given instruction.
SlotIndex getInstructionIndex(const MachineInstr *instr) const {
Mi2IndexMap::const_iterator itr = mi2iMap.find(instr);
assert(itr != mi2iMap.end() && "Instruction not found in maps.");
return itr->second;
}
/// Returns the instruction for the given index, or null if the given
/// index has no instruction associated with it.
MachineInstr* getInstructionFromIndex(SlotIndex index) const {
return index.isValid() ? index.entry().getInstr() : 0;
}
/// Returns the next non-null index.
SlotIndex getNextNonNullIndex(SlotIndex index) {
SlotIndex nextNonNull = index.getNextIndex();
while (&nextNonNull.entry() != getTail() &&
getInstructionFromIndex(nextNonNull) == 0) {
nextNonNull = nextNonNull.getNextIndex();
}
return nextNonNull;
}
/// getIndexBefore - Returns the index of the last indexed instruction
/// before MI, or the the start index of its basic block.
/// MI is not required to have an index.
SlotIndex getIndexBefore(const MachineInstr *MI) const {
const MachineBasicBlock *MBB = MI->getParent();
assert(MBB && "MI must be inserted inna basic block");
MachineBasicBlock::const_iterator I = MI, B = MBB->begin();
for (;;) {
if (I == B)
return getMBBStartIdx(MBB);
--I;
Mi2IndexMap::const_iterator MapItr = mi2iMap.find(I);
if (MapItr != mi2iMap.end())
return MapItr->second;
}
}
/// getIndexAfter - Returns the index of the first indexed instruction
/// after MI, or the end index of its basic block.
/// MI is not required to have an index.
SlotIndex getIndexAfter(const MachineInstr *MI) const {
const MachineBasicBlock *MBB = MI->getParent();
assert(MBB && "MI must be inserted inna basic block");
MachineBasicBlock::const_iterator I = MI, E = MBB->end();
for (;;) {
++I;
if (I == E)
return getMBBEndIdx(MBB);
Mi2IndexMap::const_iterator MapItr = mi2iMap.find(I);
if (MapItr != mi2iMap.end())
return MapItr->second;
}
}
/// Return the (start,end) range of the given basic block number.
const std::pair<SlotIndex, SlotIndex> &
getMBBRange(unsigned Num) const {
return MBBRanges[Num];
}
/// Return the (start,end) range of the given basic block.
const std::pair<SlotIndex, SlotIndex> &
getMBBRange(const MachineBasicBlock *MBB) const {
return getMBBRange(MBB->getNumber());
}
/// Returns the first index in the given basic block number.
SlotIndex getMBBStartIdx(unsigned Num) const {
return getMBBRange(Num).first;
}
/// Returns the first index in the given basic block.
SlotIndex getMBBStartIdx(const MachineBasicBlock *mbb) const {
return getMBBRange(mbb).first;
}
/// Returns the last index in the given basic block number.
SlotIndex getMBBEndIdx(unsigned Num) const {
return getMBBRange(Num).second;
}
/// Returns the last index in the given basic block.
SlotIndex getMBBEndIdx(const MachineBasicBlock *mbb) const {
return getMBBRange(mbb).second;
}
/// Returns the basic block which the given index falls in.
MachineBasicBlock* getMBBFromIndex(SlotIndex index) const {
if (MachineInstr *MI = getInstructionFromIndex(index))
return MI->getParent();
SmallVectorImpl<IdxMBBPair>::const_iterator I =
std::lower_bound(idx2MBBMap.begin(), idx2MBBMap.end(), index);
// Take the pair containing the index
SmallVectorImpl<IdxMBBPair>::const_iterator J =
((I != idx2MBBMap.end() && I->first > index) ||
(I == idx2MBBMap.end() && idx2MBBMap.size()>0)) ? (I-1): I;
assert(J != idx2MBBMap.end() && J->first <= index &&
index < getMBBEndIdx(J->second) &&
"index does not correspond to an MBB");
return J->second;
}
bool findLiveInMBBs(SlotIndex start, SlotIndex end,
SmallVectorImpl<MachineBasicBlock*> &mbbs) const {
SmallVectorImpl<IdxMBBPair>::const_iterator itr =
std::lower_bound(idx2MBBMap.begin(), idx2MBBMap.end(), start);
bool resVal = false;
while (itr != idx2MBBMap.end()) {
if (itr->first >= end)
break;
mbbs.push_back(itr->second);
resVal = true;
++itr;
}
return resVal;
}
/// Returns the MBB covering the given range, or null if the range covers
/// more than one basic block.
MachineBasicBlock* getMBBCoveringRange(SlotIndex start, SlotIndex end) const {
assert(start < end && "Backwards ranges not allowed.");
SmallVectorImpl<IdxMBBPair>::const_iterator itr =
std::lower_bound(idx2MBBMap.begin(), idx2MBBMap.end(), start);
if (itr == idx2MBBMap.end()) {
itr = prior(itr);
return itr->second;
}
// Check that we don't cross the boundary into this block.
if (itr->first < end)
return 0;
itr = prior(itr);
if (itr->first <= start)
return itr->second;
return 0;
}
/// Insert the given machine instruction into the mapping. Returns the
/// assigned index.
/// If Late is set and there are null indexes between mi's neighboring
/// instructions, create the new index after the null indexes instead of
/// before them.
SlotIndex insertMachineInstrInMaps(MachineInstr *mi, bool Late = false) {
assert(mi2iMap.find(mi) == mi2iMap.end() && "Instr already indexed.");
// Numbering DBG_VALUE instructions could cause code generation to be
// affected by debug information.
assert(!mi->isDebugValue() && "Cannot number DBG_VALUE instructions.");
assert(mi->getParent() != 0 && "Instr must be added to function.");
// Get the entries where mi should be inserted.
IndexListEntry *prevEntry, *nextEntry;
if (Late) {
// Insert mi's index immediately before the following instruction.
nextEntry = &getIndexAfter(mi).entry();
prevEntry = nextEntry->getPrev();
} else {
// Insert mi's index immediately after the preceeding instruction.
prevEntry = &getIndexBefore(mi).entry();
nextEntry = prevEntry->getNext();
}
// Get a number for the new instr, or 0 if there's no room currently.
// In the latter case we'll force a renumber later.
unsigned dist = ((nextEntry->getIndex() - prevEntry->getIndex())/2) & ~3u;
unsigned newNumber = prevEntry->getIndex() + dist;
// Insert a new list entry for mi.
IndexListEntry *newEntry = createEntry(mi, newNumber);
insert(nextEntry, newEntry);
// Renumber locally if we need to.
if (dist == 0)
renumberIndexes(newEntry);
SlotIndex newIndex(newEntry, SlotIndex::LOAD);
mi2iMap.insert(std::make_pair(mi, newIndex));
return newIndex;
}
/// Remove the given machine instruction from the mapping.
void removeMachineInstrFromMaps(MachineInstr *mi) {
// remove index -> MachineInstr and
// MachineInstr -> index mappings
Mi2IndexMap::iterator mi2iItr = mi2iMap.find(mi);
if (mi2iItr != mi2iMap.end()) {
IndexListEntry *miEntry(&mi2iItr->second.entry());
assert(miEntry->getInstr() == mi && "Instruction indexes broken.");
// FIXME: Eventually we want to actually delete these indexes.
miEntry->setInstr(0);
mi2iMap.erase(mi2iItr);
}
}
/// ReplaceMachineInstrInMaps - Replacing a machine instr with a new one in
/// maps used by register allocator.
void replaceMachineInstrInMaps(MachineInstr *mi, MachineInstr *newMI) {
Mi2IndexMap::iterator mi2iItr = mi2iMap.find(mi);
if (mi2iItr == mi2iMap.end())
return;
SlotIndex replaceBaseIndex = mi2iItr->second;
IndexListEntry *miEntry(&replaceBaseIndex.entry());
assert(miEntry->getInstr() == mi &&
"Mismatched instruction in index tables.");
miEntry->setInstr(newMI);
mi2iMap.erase(mi2iItr);
mi2iMap.insert(std::make_pair(newMI, replaceBaseIndex));
}
/// Add the given MachineBasicBlock into the maps.
void insertMBBInMaps(MachineBasicBlock *mbb) {
MachineFunction::iterator nextMBB =
llvm::next(MachineFunction::iterator(mbb));
IndexListEntry *startEntry = createEntry(0, 0);
IndexListEntry *stopEntry = createEntry(0, 0);
IndexListEntry *nextEntry = 0;
if (nextMBB == mbb->getParent()->end()) {
nextEntry = getTail();
} else {
nextEntry = &getMBBStartIdx(nextMBB).entry();
}
insert(nextEntry, startEntry);
insert(nextEntry, stopEntry);
SlotIndex startIdx(startEntry, SlotIndex::LOAD);
SlotIndex endIdx(nextEntry, SlotIndex::LOAD);
assert(unsigned(mbb->getNumber()) == MBBRanges.size() &&
"Blocks must be added in order");
MBBRanges.push_back(std::make_pair(startIdx, endIdx));
idx2MBBMap.push_back(IdxMBBPair(startIdx, mbb));
renumberIndexes();
std::sort(idx2MBBMap.begin(), idx2MBBMap.end(), Idx2MBBCompare());
}
};
// Specialize IntervalMapInfo for half-open slot index intervals.
template <typename> struct IntervalMapInfo;
template <> struct IntervalMapInfo<SlotIndex> {
static inline bool startLess(const SlotIndex &x, const SlotIndex &a) {
return x < a;
}
static inline bool stopLess(const SlotIndex &b, const SlotIndex &x) {
return b <= x;
}
static inline bool adjacent(const SlotIndex &a, const SlotIndex &b) {
return a == b;
}
};
}
#endif // LLVM_CODEGEN_LIVEINDEX_H
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