//
// 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 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
+// 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
#define LLVM_CODEGEN_LIVEINTERVAL_H
#include "llvm/ADT/SmallVector.h"
-#include <iosfwd>
-#include <vector>
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/AlignOf.h"
+#include "llvm/CodeGen/SlotIndexes.h"
#include <cassert>
+#include <climits>
namespace llvm {
- class MRegisterInfo;
+ 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.
+ ///
+ /// Care must be taken in interpreting the def index of the value. The
+ /// following rules apply:
+ ///
+ /// If the isDefAccurate() method returns false then def does not contain the
+ /// index of the defining MachineInstr, or even (necessarily) to a
+ /// MachineInstr at all. In general such a def index is not meaningful
+ /// and should not be used. The exception is that, for values originally
+ /// defined by PHI instructions, after PHI elimination def will contain the
+ /// index of the MBB in which the PHI originally existed. This can be used
+ /// to insert code (spills or copies) which deals with the value, which will
+ /// be live in to the block.
+ class VNInfo {
+ private:
+ enum {
+ HAS_PHI_KILL = 1,
+ REDEF_BY_EC = 1 << 1,
+ IS_PHI_DEF = 1 << 2,
+ IS_UNUSED = 1 << 3,
+ IS_DEF_ACCURATE = 1 << 4
+ };
+
+ unsigned char flags;
+ union {
+ MachineInstr *copy;
+ unsigned reg;
+ } cr;
+
+ public:
+ typedef SpecificBumpPtrAllocator<VNInfo> Allocator;
+ typedef SmallVector<SlotIndex, 4> KillSet;
+
+ /// The ID number of this value.
+ unsigned id;
+
+ /// The index of the defining instruction (if isDefAccurate() returns true).
+ SlotIndex def;
+
+ KillSet kills;
+
+ /*
+ VNInfo(LiveIntervals &li_)
+ : defflags(IS_UNUSED), id(~1U) { cr.copy = 0; }
+ */
+
+ /// VNInfo constructor.
+ /// d is presumed to point to the actual defining instr. If it doesn't
+ /// setIsDefAccurate(false) should be called after construction.
+ VNInfo(unsigned i, SlotIndex d, MachineInstr *c)
+ : flags(IS_DEF_ACCURATE), id(i), def(d) { cr.copy = c; }
+
+ /// VNInfo construtor, copies values from orig, except for the value number.
+ VNInfo(unsigned i, const VNInfo &orig)
+ : flags(orig.flags), cr(orig.cr), id(i), def(orig.def), kills(orig.kills)
+ { }
+
+ /// Copy from the parameter into this VNInfo.
+ void copyFrom(VNInfo &src) {
+ flags = src.flags;
+ cr = src.cr;
+ def = src.def;
+ kills = src.kills;
+ }
+
+ /// Used for copying value number info.
+ unsigned getFlags() const { return flags; }
+ void setFlags(unsigned flags) { this->flags = flags; }
+
+ /// For a register interval, if this VN was definied by a copy instr
+ /// getCopy() returns a pointer to it, otherwise returns 0.
+ /// For a stack interval the behaviour of this method is undefined.
+ MachineInstr* getCopy() const { return cr.copy; }
+ /// For a register interval, set the copy member.
+ /// This method should not be called on stack intervals as it may lead to
+ /// undefined behavior.
+ void setCopy(MachineInstr *c) { cr.copy = c; }
+
+ /// For a stack interval, returns the reg which this stack interval was
+ /// defined from.
+ /// For a register interval the behaviour of this method is undefined.
+ unsigned getReg() const { return cr.reg; }
+ /// For a stack interval, set the defining register.
+ /// This method should not be called on register intervals as it may lead
+ /// to undefined behaviour.
+ void setReg(unsigned reg) { cr.reg = reg; }
+
+ /// Returns true if one or more kills are PHI nodes.
+ bool hasPHIKill() const { return flags & HAS_PHI_KILL; }
+ /// Set the PHI kill flag on this value.
+ void setHasPHIKill(bool hasKill) {
+ if (hasKill)
+ flags |= HAS_PHI_KILL;
+ else
+ flags &= ~HAS_PHI_KILL;
+ }
+
+ /// Returns true if this value is re-defined by an early clobber somewhere
+ /// during the live range.
+ bool hasRedefByEC() const { return flags & REDEF_BY_EC; }
+ /// Set the "redef by early clobber" flag on this value.
+ void setHasRedefByEC(bool hasRedef) {
+ if (hasRedef)
+ flags |= REDEF_BY_EC;
+ else
+ flags &= ~REDEF_BY_EC;
+ }
+
+ /// Returns true if this value is defined by a PHI instruction (or was,
+ /// PHI instrucions may have been eliminated).
+ bool isPHIDef() const { return flags & IS_PHI_DEF; }
+ /// Set the "phi def" flag on this value.
+ void setIsPHIDef(bool phiDef) {
+ if (phiDef)
+ flags |= IS_PHI_DEF;
+ else
+ flags &= ~IS_PHI_DEF;
+ }
+
+ /// Returns true if this value is unused.
+ bool isUnused() const { return flags & IS_UNUSED; }
+ /// Set the "is unused" flag on this value.
+ void setIsUnused(bool unused) {
+ if (unused)
+ flags |= IS_UNUSED;
+ else
+ flags &= ~IS_UNUSED;
+ }
+
+ /// Returns true if the def is accurate.
+ bool isDefAccurate() const { return flags & IS_DEF_ACCURATE; }
+ /// Set the "is def accurate" flag on this value.
+ void setIsDefAccurate(bool defAccurate) {
+ if (defAccurate)
+ flags |= IS_DEF_ACCURATE;
+ else
+ flags &= ~IS_DEF_ACCURATE;
+ }
+
+ /// Returns true if the given index is a kill of this value.
+ bool isKill(SlotIndex k) const {
+ KillSet::const_iterator
+ i = std::lower_bound(kills.begin(), kills.end(), k);
+ return (i != kills.end() && *i == k);
+ }
+
+ /// addKill - Add a kill instruction index to the specified value
+ /// number.
+ void addKill(SlotIndex k) {
+ if (kills.empty()) {
+ kills.push_back(k);
+ } else {
+ KillSet::iterator
+ i = std::lower_bound(kills.begin(), kills.end(), k);
+ kills.insert(i, k);
+ }
+ }
+
+ /// Remove the specified kill index from this value's kills list.
+ /// Returns true if the value was present, otherwise returns false.
+ bool removeKill(SlotIndex k) {
+ KillSet::iterator i = std::lower_bound(kills.begin(), kills.end(), k);
+ if (i != kills.end() && *i == k) {
+ kills.erase(i);
+ return true;
+ }
+ return false;
+ }
+
+ /// Remove all kills in the range [s, e).
+ void removeKills(SlotIndex s, SlotIndex e) {
+ KillSet::iterator
+ si = std::lower_bound(kills.begin(), kills.end(), s),
+ se = std::upper_bound(kills.begin(), kills.end(), e);
+
+ kills.erase(si, se);
+ }
+
+ };
/// 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 {
- unsigned start; // Start point of the interval (inclusive)
- unsigned end; // End point of the interval (exclusive)
- unsigned ValId; // identifier for the value contained in this interval.
+ 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(SlotIndex S, SlotIndex E, VNInfo *V)
+ : start(S), end(E), valno(V) {
- LiveRange(unsigned S, unsigned E, unsigned V) : start(S), end(E), ValId(V) {
assert(S < E && "Cannot create empty or backwards range");
}
/// contains - Return true if the index is covered by this range.
///
- bool contains(unsigned I) const {
+ 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);
}
}
void dump() const;
+ void print(raw_ostream &os) const;
private:
LiveRange(); // DO NOT IMPLEMENT
};
- std::ostream& operator<<(std::ostream& os, const LiveRange &LR);
- inline bool operator<(unsigned V, const LiveRange &LR) {
+ 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, unsigned V) {
+ 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.
- struct LiveInterval {
+ class LiveInterval {
+ public:
+
typedef SmallVector<LiveRange,4> Ranges;
- unsigned reg; // the register of this interval
+ typedef SmallVector<VNInfo*,4> VNInfoList;
+
+ unsigned reg; // the register or stack slot of this interval
+ // if the top bits is set, it represents a stack slot.
float weight; // weight of this interval
Ranges ranges; // the ranges in which this register is live
- private:
- unsigned NumValues; // the number of distinct values in this interval.
- public:
-
- LiveInterval(unsigned Reg, float Weight)
- : reg(Reg), weight(Weight), NumValues(0) {
+ VNInfoList valnos; // value#'s
+
+ struct InstrSlots {
+ enum {
+ LOAD = 0,
+ USE = 1,
+ DEF = 2,
+ STORE = 3,
+ NUM = 4
+ };
+
+ };
+
+ LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
+ : reg(Reg), weight(Weight) {
+ if (IsSS)
+ reg = reg | (1U << (sizeof(unsigned)*CHAR_BIT-1));
}
typedef Ranges::iterator 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 the the
+ /// position is in a hole, this method returns an iterator pointing to the
/// LiveRange immediately after the hole.
- iterator advanceTo(iterator I, unsigned Pos) {
- if (Pos >= endNumber())
+ iterator advanceTo(iterator I, SlotIndex Pos) {
+ if (Pos >= endIndex())
return end();
while (I->end <= Pos) ++I;
return I;
}
+
+ void clear() {
+ valnos.clear();
+ ranges.clear();
+ }
+
+ /// isStackSlot - Return true if this is a stack slot interval.
+ ///
+ bool isStackSlot() const {
+ return reg & (1U << (sizeof(unsigned)*CHAR_BIT-1));
+ }
+
+ /// getStackSlotIndex - Return stack slot index if this is a stack slot
+ /// interval.
+ int getStackSlotIndex() const {
+ assert(isStackSlot() && "Interval is not a stack slot interval!");
+ return reg & ~(1U << (sizeof(unsigned)*CHAR_BIT-1));
+ }
+
+ 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];
+ }
- void swap(LiveInterval& other) {
- std::swap(reg, other.reg);
- std::swap(weight, other.weight);
- ranges.swap(other.ranges);
- std::swap(NumValues, other.NumValues);
+ /// getNextValue - Create a new value number and return it. MIIdx specifies
+ /// the instruction that defines the value number.
+ VNInfo *getNextValue(SlotIndex def, MachineInstr *CopyMI,
+ bool isDefAccurate, VNInfo::Allocator &VNInfoAllocator) {
+ VNInfo *VNI = VNInfoAllocator.Allocate();
+ new (VNI) VNInfo((unsigned)valnos.size(), def, CopyMI);
+ VNI->setIsDefAccurate(isDefAccurate);
+ valnos.push_back(VNI);
+ return VNI;
}
- bool containsOneValue() const { return NumValues == 1; }
+ /// 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 = VNInfoAllocator.Allocate();
+ new (VNI) VNInfo((unsigned)valnos.size(), *orig);
+ valnos.push_back(VNI);
+ return VNI;
+ }
- unsigned getNextValue() {
- return NumValues++;
+ /// addKills - Add a number of kills into the VNInfo kill vector. If this
+ /// interval is live at a kill point, then the kill is not added.
+ void addKills(VNInfo *VNI, const VNInfo::KillSet &kills) {
+ for (unsigned i = 0, e = static_cast<unsigned>(kills.size());
+ i != e; ++i) {
+ if (!liveBeforeAndAt(kills[i])) {
+ VNI->addKill(kills[i]);
+ }
+ }
}
+ /// isOnlyLROfValNo - Return true if the specified live range is the only
+ /// one defined by the its val#.
+ bool isOnlyLROfValNo(const LiveRange *LR) {
+ for (const_iterator I = begin(), E = end(); I != E; ++I) {
+ const LiveRange *Tmp = I;
+ if (Tmp != LR && Tmp->valno == LR->valno)
+ return false;
+ }
+ return true;
+ }
+
+ /// 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);
+
+ /// MergeInClobberRanges - For any live ranges that are not defined in the
+ /// current interval, but are defined in the Clobbers interval, mark them
+ /// used with an unknown definition value. Caller must pass in reference to
+ /// VNInfoAllocator since it will create a new val#.
+ void MergeInClobberRanges(LiveIntervals &li_,
+ const LiveInterval &Clobbers,
+ VNInfo::Allocator &VNInfoAllocator);
+
+ /// MergeInClobberRange - Same as MergeInClobberRanges except it merge in a
+ /// single LiveRange only.
+ void MergeInClobberRange(LiveIntervals &li_,
+ SlotIndex Start,
+ SlotIndex End,
+ VNInfo::Allocator &VNInfoAllocator);
+
+ /// 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);
+
+ /// Copy - Copy the specified live interval. This copies all the fields
+ /// except for the register of the interval.
+ void Copy(const LiveInterval &RHS, MachineRegisterInfo *MRI,
+ VNInfo::Allocator &VNInfoAllocator);
+
bool empty() const { return ranges.empty(); }
- /// beginNumber - Return the lowest numbered slot covered by interval.
- unsigned beginNumber() const {
- assert(!empty() && "empty interval for register");
+ /// 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.
- unsigned endNumber() const {
- assert(!empty() && "empty interval for register");
+ SlotIndex endIndex() const {
+ assert(!empty() && "Call to endIndex() on empty interval.");
return ranges.back().end;
}
- bool expiredAt(unsigned index) const {
- return index >= endNumber();
+ bool expiredAt(SlotIndex index) const {
+ return index >= endIndex();
}
- bool liveAt(unsigned index) const;
+ bool liveAt(SlotIndex index) const;
+
+ // liveBeforeAndAt - Check if the interval is live at the index and the
+ // index just before it. If index is liveAt, check if it starts a new live
+ // range.If it does, then check if the previous live range ends at index-1.
+ bool liveBeforeAndAt(SlotIndex index) const;
+
+ /// 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.
- const LiveRange *getLiveRangeContaining(unsigned Idx) const;
+ LiveRange *getLiveRangeContaining(SlotIndex Idx) {
+ iterator I = FindLiveRangeContaining(Idx);
+ return I == end() ? 0 : &*I;
+ }
+
+ /// FindLiveRangeContaining - Return an iterator to the live range that
+ /// contains the specified index, or end() if there is none.
+ const_iterator FindLiveRangeContaining(SlotIndex Idx) const;
+ /// FindLiveRangeContaining - Return an iterator to the live range that
+ /// contains the specified index, or end() if there is none.
+ iterator FindLiveRangeContaining(SlotIndex Idx);
- /// joinable - Two intervals are joinable if the either don't overlap at all
- /// or if the destination of the copy is a single assignment value, and it
- /// only overlaps with one value in the source interval.
- bool joinable(const LiveInterval& other, unsigned CopyIdx) const;
+ /// findDefinedVNInfo - Find the by the specified
+ /// index (register interval) or defined
+ VNInfo *findDefinedVNInfoForRegInt(SlotIndex Idx) const;
- /// getOverlapingRanges - Given another live interval which is defined as a
- /// copy from this one, return a list of all of the live ranges where the
- /// two overlap and have different value numbers.
- void getOverlapingRanges(const LiveInterval &Other, unsigned CopyIdx,
- std::vector<LiveRange*> &Ranges);
+ /// findDefinedVNInfo - Find the VNInfo that's defined by the specified
+ /// register (stack inteval only).
+ VNInfo *findDefinedVNInfoForStackInt(unsigned Reg) const;
+
/// overlaps - Return true if the intersection of the two live intervals is
/// not empty.
bool overlaps(const LiveInterval& other) const {
return overlapsFrom(other, other.begin());
}
+ /// 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.
addRangeFrom(LR, ranges.begin());
}
- /// join - Join two live intervals (this, and other) together. This
- /// operation is the result of a copy instruction in the source program,
- /// that occurs at index 'CopyIdx' that copies from 'other' to 'this'. This
- /// destroys 'other'.
- void join(LiveInterval& other, unsigned CopyIdx);
+ /// 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);
/// removeRange - Remove the specified range from this interval. Note that
- /// the range must already be in this interval in its entirety.
- void removeRange(unsigned Start, unsigned End);
+ /// 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);
+
+ /// scaleNumbering - Renumber VNI and ranges to provide gaps for new
+ /// instructions.
+ void scaleNumbering(unsigned factor);
+
+ /// getSize - Returns the sum of sizes of all the LiveRange's.
+ ///
+ unsigned getSize() const;
+
+ /// isSpillable - Can this interval be spilled?
+ bool isSpillable() const {
+ return weight != HUGE_VALF;
+ }
+
+ /// markNotSpillable - Mark interval as not spillable
+ void markNotSpillable() {
+ weight = HUGE_VALF;
+ }
+
+ /// ComputeJoinedWeight - Set the weight of a live interval after
+ /// Other has been merged into it.
+ void ComputeJoinedWeight(const LiveInterval &Other);
bool operator<(const LiveInterval& other) const {
- return beginNumber() < other.beginNumber();
+ const SlotIndex &thisIndex = beginIndex();
+ const SlotIndex &otherIndex = other.beginIndex();
+ return (thisIndex < otherIndex ||
+ (thisIndex == otherIndex && reg < other.reg));
}
- void print(std::ostream &OS, const MRegisterInfo *MRI = 0) const;
+ void print(raw_ostream &OS, const TargetRegisterInfo *TRI = 0) const;
void dump() const;
private:
+
Ranges::iterator addRangeFrom(LiveRange LR, Ranges::iterator From);
- void extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd);
- Ranges::iterator extendIntervalStartTo(Ranges::iterator I, unsigned NewStr);
+ void extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd);
+ Ranges::iterator extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStr);
+
LiveInterval& operator=(const LiveInterval& rhs); // DO NOT IMPLEMENT
+
};
- inline std::ostream &operator<<(std::ostream &OS, const LiveInterval &LI) {
+ inline raw_ostream &operator<<(raw_ostream &OS, const LiveInterval &LI) {
LI.print(OS);
return OS;
}