mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-31 12:30:06 +00:00
Performance is the same, but LiveRangeUpdater has a more flexible interface. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175645 91177308-0d34-0410-b5e6-96231b3b80d8
668 lines
24 KiB
C++
668 lines
24 KiB
C++
//===-- llvm/CodeGen/LiveInterval.h - Interval 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 the LiveRange and LiveInterval classes. Given some
|
|
// numbering of each the machine instructions 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' and 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). Each
|
|
// individual range is represented as an instance of LiveRange, and the whole
|
|
// interval is represented as an instance of LiveInterval.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_CODEGEN_LIVEINTERVAL_H
|
|
#define LLVM_CODEGEN_LIVEINTERVAL_H
|
|
|
|
#include "llvm/ADT/IntEqClasses.h"
|
|
#include "llvm/CodeGen/SlotIndexes.h"
|
|
#include "llvm/Support/AlignOf.h"
|
|
#include "llvm/Support/Allocator.h"
|
|
#include <cassert>
|
|
#include <climits>
|
|
|
|
namespace llvm {
|
|
class CoalescerPair;
|
|
class LiveIntervals;
|
|
class MachineInstr;
|
|
class MachineRegisterInfo;
|
|
class TargetRegisterInfo;
|
|
class raw_ostream;
|
|
|
|
/// VNInfo - Value Number Information.
|
|
/// This class holds information about a machine level values, including
|
|
/// definition and use points.
|
|
///
|
|
class VNInfo {
|
|
public:
|
|
typedef BumpPtrAllocator Allocator;
|
|
|
|
/// The ID number of this value.
|
|
unsigned id;
|
|
|
|
/// The index of the defining instruction.
|
|
SlotIndex def;
|
|
|
|
/// VNInfo constructor.
|
|
VNInfo(unsigned i, SlotIndex d)
|
|
: id(i), def(d)
|
|
{ }
|
|
|
|
/// VNInfo construtor, copies values from orig, except for the value number.
|
|
VNInfo(unsigned i, const VNInfo &orig)
|
|
: id(i), def(orig.def)
|
|
{ }
|
|
|
|
/// Copy from the parameter into this VNInfo.
|
|
void copyFrom(VNInfo &src) {
|
|
def = src.def;
|
|
}
|
|
|
|
/// Returns true if this value is defined by a PHI instruction (or was,
|
|
/// PHI instrucions may have been eliminated).
|
|
/// PHI-defs begin at a block boundary, all other defs begin at register or
|
|
/// EC slots.
|
|
bool isPHIDef() const { return def.isBlock(); }
|
|
|
|
/// Returns true if this value is unused.
|
|
bool isUnused() const { return !def.isValid(); }
|
|
|
|
/// Mark this value as unused.
|
|
void markUnused() { def = SlotIndex(); }
|
|
};
|
|
|
|
/// LiveRange structure - This represents a simple register range in the
|
|
/// program, with an inclusive start point and an exclusive end point.
|
|
/// These ranges are rendered as [start,end).
|
|
struct LiveRange {
|
|
SlotIndex start; // Start point of the interval (inclusive)
|
|
SlotIndex end; // End point of the interval (exclusive)
|
|
VNInfo *valno; // identifier for the value contained in this interval.
|
|
|
|
LiveRange() : valno(0) {}
|
|
|
|
LiveRange(SlotIndex S, SlotIndex E, VNInfo *V)
|
|
: start(S), end(E), valno(V) {
|
|
assert(S < E && "Cannot create empty or backwards range");
|
|
}
|
|
|
|
/// contains - Return true if the index is covered by this range.
|
|
///
|
|
bool contains(SlotIndex I) const {
|
|
return start <= I && I < end;
|
|
}
|
|
|
|
/// containsRange - Return true if the given range, [S, E), is covered by
|
|
/// this range.
|
|
bool containsRange(SlotIndex S, SlotIndex E) const {
|
|
assert((S < E) && "Backwards interval?");
|
|
return (start <= S && S < end) && (start < E && E <= end);
|
|
}
|
|
|
|
bool operator<(const LiveRange &LR) const {
|
|
return start < LR.start || (start == LR.start && end < LR.end);
|
|
}
|
|
bool operator==(const LiveRange &LR) const {
|
|
return start == LR.start && end == LR.end;
|
|
}
|
|
|
|
void dump() const;
|
|
void print(raw_ostream &os) const;
|
|
};
|
|
|
|
template <> struct isPodLike<LiveRange> { static const bool value = true; };
|
|
|
|
raw_ostream& operator<<(raw_ostream& os, const LiveRange &LR);
|
|
|
|
|
|
inline bool operator<(SlotIndex V, const LiveRange &LR) {
|
|
return V < LR.start;
|
|
}
|
|
|
|
inline bool operator<(const LiveRange &LR, SlotIndex V) {
|
|
return LR.start < V;
|
|
}
|
|
|
|
/// LiveInterval - This class represents some number of live ranges for a
|
|
/// register or value. This class also contains a bit of register allocator
|
|
/// state.
|
|
class LiveInterval {
|
|
public:
|
|
|
|
typedef SmallVector<LiveRange,4> Ranges;
|
|
typedef SmallVector<VNInfo*,4> VNInfoList;
|
|
|
|
const unsigned reg; // the register or stack slot of this interval.
|
|
float weight; // weight of this interval
|
|
Ranges ranges; // the ranges in which this register is live
|
|
VNInfoList valnos; // value#'s
|
|
|
|
struct InstrSlots {
|
|
enum {
|
|
LOAD = 0,
|
|
USE = 1,
|
|
DEF = 2,
|
|
STORE = 3,
|
|
NUM = 4
|
|
};
|
|
|
|
};
|
|
|
|
LiveInterval(unsigned Reg, float Weight)
|
|
: reg(Reg), weight(Weight) {}
|
|
|
|
typedef Ranges::iterator iterator;
|
|
iterator begin() { return ranges.begin(); }
|
|
iterator end() { return ranges.end(); }
|
|
|
|
typedef Ranges::const_iterator const_iterator;
|
|
const_iterator begin() const { return ranges.begin(); }
|
|
const_iterator end() const { return ranges.end(); }
|
|
|
|
typedef VNInfoList::iterator vni_iterator;
|
|
vni_iterator vni_begin() { return valnos.begin(); }
|
|
vni_iterator vni_end() { return valnos.end(); }
|
|
|
|
typedef VNInfoList::const_iterator const_vni_iterator;
|
|
const_vni_iterator vni_begin() const { return valnos.begin(); }
|
|
const_vni_iterator vni_end() const { return valnos.end(); }
|
|
|
|
/// advanceTo - Advance the specified iterator to point to the LiveRange
|
|
/// containing the specified position, or end() if the position is past the
|
|
/// end of the interval. If no LiveRange contains this position, but the
|
|
/// position is in a hole, this method returns an iterator pointing to the
|
|
/// LiveRange immediately after the hole.
|
|
iterator advanceTo(iterator I, SlotIndex Pos) {
|
|
assert(I != end());
|
|
if (Pos >= endIndex())
|
|
return end();
|
|
while (I->end <= Pos) ++I;
|
|
return I;
|
|
}
|
|
|
|
/// find - Return an iterator pointing to the first range that ends after
|
|
/// Pos, or end(). This is the same as advanceTo(begin(), Pos), but faster
|
|
/// when searching large intervals.
|
|
///
|
|
/// If Pos is contained in a LiveRange, that range is returned.
|
|
/// If Pos is in a hole, the following LiveRange is returned.
|
|
/// If Pos is beyond endIndex, end() is returned.
|
|
iterator find(SlotIndex Pos);
|
|
|
|
const_iterator find(SlotIndex Pos) const {
|
|
return const_cast<LiveInterval*>(this)->find(Pos);
|
|
}
|
|
|
|
void clear() {
|
|
valnos.clear();
|
|
ranges.clear();
|
|
}
|
|
|
|
bool hasAtLeastOneValue() const { return !valnos.empty(); }
|
|
|
|
bool containsOneValue() const { return valnos.size() == 1; }
|
|
|
|
unsigned getNumValNums() const { return (unsigned)valnos.size(); }
|
|
|
|
/// getValNumInfo - Returns pointer to the specified val#.
|
|
///
|
|
inline VNInfo *getValNumInfo(unsigned ValNo) {
|
|
return valnos[ValNo];
|
|
}
|
|
inline const VNInfo *getValNumInfo(unsigned ValNo) const {
|
|
return valnos[ValNo];
|
|
}
|
|
|
|
/// containsValue - Returns true if VNI belongs to this interval.
|
|
bool containsValue(const VNInfo *VNI) const {
|
|
return VNI && VNI->id < getNumValNums() && VNI == getValNumInfo(VNI->id);
|
|
}
|
|
|
|
/// getNextValue - Create a new value number and return it. MIIdx specifies
|
|
/// the instruction that defines the value number.
|
|
VNInfo *getNextValue(SlotIndex def, VNInfo::Allocator &VNInfoAllocator) {
|
|
VNInfo *VNI =
|
|
new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), def);
|
|
valnos.push_back(VNI);
|
|
return VNI;
|
|
}
|
|
|
|
/// createDeadDef - Make sure the interval has a value defined at Def.
|
|
/// If one already exists, return it. Otherwise allocate a new value and
|
|
/// add liveness for a dead def.
|
|
VNInfo *createDeadDef(SlotIndex Def, VNInfo::Allocator &VNInfoAllocator);
|
|
|
|
/// Create a copy of the given value. The new value will be identical except
|
|
/// for the Value number.
|
|
VNInfo *createValueCopy(const VNInfo *orig,
|
|
VNInfo::Allocator &VNInfoAllocator) {
|
|
VNInfo *VNI =
|
|
new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), *orig);
|
|
valnos.push_back(VNI);
|
|
return VNI;
|
|
}
|
|
|
|
/// RenumberValues - Renumber all values in order of appearance and remove
|
|
/// unused values.
|
|
void RenumberValues(LiveIntervals &lis);
|
|
|
|
/// MergeValueNumberInto - This method is called when two value nubmers
|
|
/// are found to be equivalent. This eliminates V1, replacing all
|
|
/// LiveRanges with the V1 value number with the V2 value number. This can
|
|
/// cause merging of V1/V2 values numbers and compaction of the value space.
|
|
VNInfo* MergeValueNumberInto(VNInfo *V1, VNInfo *V2);
|
|
|
|
/// MergeValueInAsValue - Merge all of the live ranges of a specific val#
|
|
/// in RHS into this live interval as the specified value number.
|
|
/// The LiveRanges in RHS are allowed to overlap with LiveRanges in the
|
|
/// current interval, it will replace the value numbers of the overlaped
|
|
/// live ranges with the specified value number.
|
|
void MergeRangesInAsValue(const LiveInterval &RHS, VNInfo *LHSValNo);
|
|
|
|
/// MergeValueInAsValue - Merge all of the live ranges of a specific val#
|
|
/// in RHS into this live interval as the specified value number.
|
|
/// The LiveRanges in RHS are allowed to overlap with LiveRanges in the
|
|
/// current interval, but only if the overlapping LiveRanges have the
|
|
/// specified value number.
|
|
void MergeValueInAsValue(const LiveInterval &RHS,
|
|
const VNInfo *RHSValNo, VNInfo *LHSValNo);
|
|
|
|
bool empty() const { return ranges.empty(); }
|
|
|
|
/// beginIndex - Return the lowest numbered slot covered by interval.
|
|
SlotIndex beginIndex() const {
|
|
assert(!empty() && "Call to beginIndex() on empty interval.");
|
|
return ranges.front().start;
|
|
}
|
|
|
|
/// endNumber - return the maximum point of the interval of the whole,
|
|
/// exclusive.
|
|
SlotIndex endIndex() const {
|
|
assert(!empty() && "Call to endIndex() on empty interval.");
|
|
return ranges.back().end;
|
|
}
|
|
|
|
bool expiredAt(SlotIndex index) const {
|
|
return index >= endIndex();
|
|
}
|
|
|
|
bool liveAt(SlotIndex index) const {
|
|
const_iterator r = find(index);
|
|
return r != end() && r->start <= index;
|
|
}
|
|
|
|
/// killedAt - Return true if a live range ends at index. Note that the kill
|
|
/// point is not contained in the half-open live range. It is usually the
|
|
/// getDefIndex() slot following its last use.
|
|
bool killedAt(SlotIndex index) const {
|
|
const_iterator r = find(index.getRegSlot(true));
|
|
return r != end() && r->end == index;
|
|
}
|
|
|
|
/// getLiveRangeContaining - Return the live range that contains the
|
|
/// specified index, or null if there is none.
|
|
const LiveRange *getLiveRangeContaining(SlotIndex Idx) const {
|
|
const_iterator I = FindLiveRangeContaining(Idx);
|
|
return I == end() ? 0 : &*I;
|
|
}
|
|
|
|
/// getLiveRangeContaining - Return the live range that contains the
|
|
/// specified index, or null if there is none.
|
|
LiveRange *getLiveRangeContaining(SlotIndex Idx) {
|
|
iterator I = FindLiveRangeContaining(Idx);
|
|
return I == end() ? 0 : &*I;
|
|
}
|
|
|
|
/// getVNInfoAt - Return the VNInfo that is live at Idx, or NULL.
|
|
VNInfo *getVNInfoAt(SlotIndex Idx) const {
|
|
const_iterator I = FindLiveRangeContaining(Idx);
|
|
return I == end() ? 0 : I->valno;
|
|
}
|
|
|
|
/// getVNInfoBefore - Return the VNInfo that is live up to but not
|
|
/// necessarilly including Idx, or NULL. Use this to find the reaching def
|
|
/// used by an instruction at this SlotIndex position.
|
|
VNInfo *getVNInfoBefore(SlotIndex Idx) const {
|
|
const_iterator I = FindLiveRangeContaining(Idx.getPrevSlot());
|
|
return I == end() ? 0 : I->valno;
|
|
}
|
|
|
|
/// FindLiveRangeContaining - Return an iterator to the live range that
|
|
/// contains the specified index, or end() if there is none.
|
|
iterator FindLiveRangeContaining(SlotIndex Idx) {
|
|
iterator I = find(Idx);
|
|
return I != end() && I->start <= Idx ? I : end();
|
|
}
|
|
|
|
const_iterator FindLiveRangeContaining(SlotIndex Idx) const {
|
|
const_iterator I = find(Idx);
|
|
return I != end() && I->start <= Idx ? I : end();
|
|
}
|
|
|
|
/// overlaps - Return true if the intersection of the two live intervals is
|
|
/// not empty.
|
|
bool overlaps(const LiveInterval& other) const {
|
|
if (other.empty())
|
|
return false;
|
|
return overlapsFrom(other, other.begin());
|
|
}
|
|
|
|
/// overlaps - Return true if the two intervals have overlapping segments
|
|
/// that are not coalescable according to CP.
|
|
///
|
|
/// Overlapping segments where one interval is defined by a coalescable
|
|
/// copy are allowed.
|
|
bool overlaps(const LiveInterval &Other, const CoalescerPair &CP,
|
|
const SlotIndexes&) const;
|
|
|
|
/// overlaps - Return true if the live interval overlaps a range specified
|
|
/// by [Start, End).
|
|
bool overlaps(SlotIndex Start, SlotIndex End) const;
|
|
|
|
/// overlapsFrom - Return true if the intersection of the two live intervals
|
|
/// is not empty. The specified iterator is a hint that we can begin
|
|
/// scanning the Other interval starting at I.
|
|
bool overlapsFrom(const LiveInterval& other, const_iterator I) const;
|
|
|
|
/// addRange - Add the specified LiveRange to this interval, merging
|
|
/// intervals as appropriate. This returns an iterator to the inserted live
|
|
/// range (which may have grown since it was inserted.
|
|
iterator addRange(LiveRange LR) {
|
|
return addRangeFrom(LR, ranges.begin());
|
|
}
|
|
|
|
/// extendInBlock - If this interval is live before Kill in the basic block
|
|
/// that starts at StartIdx, extend it to be live up to Kill, and return
|
|
/// the value. If there is no live range before Kill, return NULL.
|
|
VNInfo *extendInBlock(SlotIndex StartIdx, SlotIndex Kill);
|
|
|
|
/// join - Join two live intervals (this, and other) together. This applies
|
|
/// mappings to the value numbers in the LHS/RHS intervals as specified. If
|
|
/// the intervals are not joinable, this aborts.
|
|
void join(LiveInterval &Other,
|
|
const int *ValNoAssignments,
|
|
const int *RHSValNoAssignments,
|
|
SmallVector<VNInfo*, 16> &NewVNInfo,
|
|
MachineRegisterInfo *MRI);
|
|
|
|
/// isInOneLiveRange - Return true if the range specified is entirely in the
|
|
/// a single LiveRange of the live interval.
|
|
bool isInOneLiveRange(SlotIndex Start, SlotIndex End) const {
|
|
const_iterator r = find(Start);
|
|
return r != end() && r->containsRange(Start, End);
|
|
}
|
|
|
|
/// removeRange - Remove the specified range from this interval. Note that
|
|
/// the range must be a single LiveRange in its entirety.
|
|
void removeRange(SlotIndex Start, SlotIndex End,
|
|
bool RemoveDeadValNo = false);
|
|
|
|
void removeRange(LiveRange LR, bool RemoveDeadValNo = false) {
|
|
removeRange(LR.start, LR.end, RemoveDeadValNo);
|
|
}
|
|
|
|
/// removeValNo - Remove all the ranges defined by the specified value#.
|
|
/// Also remove the value# from value# list.
|
|
void removeValNo(VNInfo *ValNo);
|
|
|
|
/// getSize - Returns the sum of sizes of all the LiveRange's.
|
|
///
|
|
unsigned getSize() const;
|
|
|
|
/// Returns true if the live interval is zero length, i.e. no live ranges
|
|
/// span instructions. It doesn't pay to spill such an interval.
|
|
bool isZeroLength(SlotIndexes *Indexes) const {
|
|
for (const_iterator i = begin(), e = end(); i != e; ++i)
|
|
if (Indexes->getNextNonNullIndex(i->start).getBaseIndex() <
|
|
i->end.getBaseIndex())
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/// isSpillable - Can this interval be spilled?
|
|
bool isSpillable() const {
|
|
return weight != HUGE_VALF;
|
|
}
|
|
|
|
/// markNotSpillable - Mark interval as not spillable
|
|
void markNotSpillable() {
|
|
weight = HUGE_VALF;
|
|
}
|
|
|
|
bool operator<(const LiveInterval& other) const {
|
|
const SlotIndex &thisIndex = beginIndex();
|
|
const SlotIndex &otherIndex = other.beginIndex();
|
|
return (thisIndex < otherIndex ||
|
|
(thisIndex == otherIndex && reg < other.reg));
|
|
}
|
|
|
|
void print(raw_ostream &OS) const;
|
|
void dump() const;
|
|
|
|
/// \brief Walk the interval and assert if any invariants fail to hold.
|
|
///
|
|
/// Note that this is a no-op when asserts are disabled.
|
|
#ifdef NDEBUG
|
|
void verify() const {}
|
|
#else
|
|
void verify() const;
|
|
#endif
|
|
|
|
private:
|
|
|
|
Ranges::iterator addRangeFrom(LiveRange LR, Ranges::iterator From);
|
|
void extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd);
|
|
Ranges::iterator extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStr);
|
|
void markValNoForDeletion(VNInfo *V);
|
|
|
|
LiveInterval& operator=(const LiveInterval& rhs) LLVM_DELETED_FUNCTION;
|
|
|
|
};
|
|
|
|
inline raw_ostream &operator<<(raw_ostream &OS, const LiveInterval &LI) {
|
|
LI.print(OS);
|
|
return OS;
|
|
}
|
|
|
|
/// Helper class for performant LiveInterval bulk updates.
|
|
///
|
|
/// Calling LiveInterval::addRange() repeatedly can be expensive on large
|
|
/// live ranges because segments after the insertion point may need to be
|
|
/// shifted. The LiveRangeUpdater class can defer the shifting when adding
|
|
/// many segments in order.
|
|
///
|
|
/// The LiveInterval will be in an invalid state until flush() is called.
|
|
class LiveRangeUpdater {
|
|
LiveInterval *LI;
|
|
SlotIndex LastStart;
|
|
LiveInterval::iterator WriteI;
|
|
LiveInterval::iterator ReadI;
|
|
SmallVector<LiveRange, 16> Spills;
|
|
void mergeSpills();
|
|
|
|
public:
|
|
/// Create a LiveRangeUpdater for adding segments to LI.
|
|
/// LI will temporarily be in an invalid state until flush() is called.
|
|
LiveRangeUpdater(LiveInterval *li = 0) : LI(li) {}
|
|
|
|
~LiveRangeUpdater() { flush(); }
|
|
|
|
/// Add a segment to LI and coalesce when possible, just like LI.addRange().
|
|
/// Segments should be added in increasing start order for best performance.
|
|
void add(LiveRange);
|
|
|
|
void add(SlotIndex Start, SlotIndex End, VNInfo *VNI) {
|
|
add(LiveRange(Start, End, VNI));
|
|
}
|
|
|
|
/// Return true if the LI is currently in an invalid state, and flush()
|
|
/// needs to be called.
|
|
bool isDirty() const { return LastStart.isValid(); }
|
|
|
|
/// Flush the updater state to LI so it is valid and contains all added
|
|
/// segments.
|
|
void flush();
|
|
|
|
/// Select a different destination live range.
|
|
void setDest(LiveInterval *li) {
|
|
if (LI != li && isDirty())
|
|
flush();
|
|
LI = li;
|
|
}
|
|
|
|
/// Get the current destination live range.
|
|
LiveInterval *getDest() const { return LI; }
|
|
|
|
void dump() const;
|
|
void print(raw_ostream&) const;
|
|
};
|
|
|
|
inline raw_ostream &operator<<(raw_ostream &OS, const LiveRangeUpdater &X) {
|
|
X.print(OS);
|
|
return OS;
|
|
}
|
|
|
|
/// LiveRangeQuery - Query information about a live range around a given
|
|
/// instruction. This class hides the implementation details of live ranges,
|
|
/// and it should be used as the primary interface for examining live ranges
|
|
/// around instructions.
|
|
///
|
|
class LiveRangeQuery {
|
|
VNInfo *EarlyVal;
|
|
VNInfo *LateVal;
|
|
SlotIndex EndPoint;
|
|
bool Kill;
|
|
|
|
public:
|
|
/// Create a LiveRangeQuery for the given live range and instruction index.
|
|
/// The sub-instruction slot of Idx doesn't matter, only the instruction it
|
|
/// refers to is considered.
|
|
LiveRangeQuery(const LiveInterval &LI, SlotIndex Idx)
|
|
: EarlyVal(0), LateVal(0), Kill(false) {
|
|
// Find the segment that enters the instruction.
|
|
LiveInterval::const_iterator I = LI.find(Idx.getBaseIndex());
|
|
LiveInterval::const_iterator E = LI.end();
|
|
if (I == E)
|
|
return;
|
|
// Is this an instruction live-in segment?
|
|
// If Idx is the start index of a basic block, include live-in segments
|
|
// that start at Idx.getBaseIndex().
|
|
if (I->start <= Idx.getBaseIndex()) {
|
|
EarlyVal = I->valno;
|
|
EndPoint = I->end;
|
|
// Move to the potentially live-out segment.
|
|
if (SlotIndex::isSameInstr(Idx, I->end)) {
|
|
Kill = true;
|
|
if (++I == E)
|
|
return;
|
|
}
|
|
// Special case: A PHIDef value can have its def in the middle of a
|
|
// segment if the value happens to be live out of the layout
|
|
// predecessor.
|
|
// Such a value is not live-in.
|
|
if (EarlyVal->def == Idx.getBaseIndex())
|
|
EarlyVal = 0;
|
|
}
|
|
// I now points to the segment that may be live-through, or defined by
|
|
// this instr. Ignore segments starting after the current instr.
|
|
if (SlotIndex::isEarlierInstr(Idx, I->start))
|
|
return;
|
|
LateVal = I->valno;
|
|
EndPoint = I->end;
|
|
}
|
|
|
|
/// Return the value that is live-in to the instruction. This is the value
|
|
/// that will be read by the instruction's use operands. Return NULL if no
|
|
/// value is live-in.
|
|
VNInfo *valueIn() const {
|
|
return EarlyVal;
|
|
}
|
|
|
|
/// Return true if the live-in value is killed by this instruction. This
|
|
/// means that either the live range ends at the instruction, or it changes
|
|
/// value.
|
|
bool isKill() const {
|
|
return Kill;
|
|
}
|
|
|
|
/// Return true if this instruction has a dead def.
|
|
bool isDeadDef() const {
|
|
return EndPoint.isDead();
|
|
}
|
|
|
|
/// Return the value leaving the instruction, if any. This can be a
|
|
/// live-through value, or a live def. A dead def returns NULL.
|
|
VNInfo *valueOut() const {
|
|
return isDeadDef() ? 0 : LateVal;
|
|
}
|
|
|
|
/// Return the value defined by this instruction, if any. This includes
|
|
/// dead defs, it is the value created by the instruction's def operands.
|
|
VNInfo *valueDefined() const {
|
|
return EarlyVal == LateVal ? 0 : LateVal;
|
|
}
|
|
|
|
/// Return the end point of the last live range segment to interact with
|
|
/// the instruction, if any.
|
|
///
|
|
/// The end point is an invalid SlotIndex only if the live range doesn't
|
|
/// intersect the instruction at all.
|
|
///
|
|
/// The end point may be at or past the end of the instruction's basic
|
|
/// block. That means the value was live out of the block.
|
|
SlotIndex endPoint() const {
|
|
return EndPoint;
|
|
}
|
|
};
|
|
|
|
/// ConnectedVNInfoEqClasses - Helper class that can divide VNInfos in a
|
|
/// LiveInterval into equivalence clases of connected components. A
|
|
/// LiveInterval that has multiple connected components can be broken into
|
|
/// multiple LiveIntervals.
|
|
///
|
|
/// Given a LiveInterval that may have multiple connected components, run:
|
|
///
|
|
/// unsigned numComps = ConEQ.Classify(LI);
|
|
/// if (numComps > 1) {
|
|
/// // allocate numComps-1 new LiveIntervals into LIS[1..]
|
|
/// ConEQ.Distribute(LIS);
|
|
/// }
|
|
|
|
class ConnectedVNInfoEqClasses {
|
|
LiveIntervals &LIS;
|
|
IntEqClasses EqClass;
|
|
|
|
// Note that values a and b are connected.
|
|
void Connect(unsigned a, unsigned b);
|
|
|
|
unsigned Renumber();
|
|
|
|
public:
|
|
explicit ConnectedVNInfoEqClasses(LiveIntervals &lis) : LIS(lis) {}
|
|
|
|
/// Classify - Classify the values in LI into connected components.
|
|
/// Return the number of connected components.
|
|
unsigned Classify(const LiveInterval *LI);
|
|
|
|
/// getEqClass - Classify creates equivalence classes numbered 0..N. Return
|
|
/// the equivalence class assigned the VNI.
|
|
unsigned getEqClass(const VNInfo *VNI) const { return EqClass[VNI->id]; }
|
|
|
|
/// Distribute - Distribute values in LIV[0] into a separate LiveInterval
|
|
/// for each connected component. LIV must have a LiveInterval for each
|
|
/// connected component. The LiveIntervals in Liv[1..] must be empty.
|
|
/// Instructions using LIV[0] are rewritten.
|
|
void Distribute(LiveInterval *LIV[], MachineRegisterInfo &MRI);
|
|
|
|
};
|
|
|
|
}
|
|
#endif
|