// 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' abd there is no instruction with number i' < i such
+// 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
#ifndef LLVM_CODEGEN_LIVEINTERVAL_H
#define LLVM_CODEGEN_LIVEINTERVAL_H
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Streams.h"
#include <iosfwd>
#include <vector>
#include <cassert>
namespace llvm {
+ class MachineInstr;
+ class MRegisterInfo;
+
/// 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)
- LiveRange(unsigned S, unsigned E) : start(S), end(E) {
+ unsigned end; // End point of the interval (exclusive)
+ unsigned ValId; // identifier for the value contained in this interval.
+
+ LiveRange(unsigned S, unsigned E, unsigned V) : start(S), end(E), ValId(V) {
assert(S < E && "Cannot create empty or backwards range");
}
bool operator==(const LiveRange &LR) const {
return start == LR.start && end == LR.end;
}
+
+ void dump() const;
+ void print(std::ostream &os) const;
+ void print(std::ostream *os) const { if (os) print(*os); }
+
private:
LiveRange(); // DO NOT IMPLEMENT
};
+
std::ostream& operator<<(std::ostream& os, const LiveRange &LR);
+
inline bool operator<(unsigned V, const LiveRange &LR) {
return V < LR.start;
}
+ inline bool operator<(const LiveRange &LR, unsigned 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 {
- typedef std::vector<LiveRange> Ranges;
+ typedef SmallVector<LiveRange,4> Ranges;
unsigned reg; // the register of this interval
+ unsigned preference; // preferred register to allocate for this interval
float weight; // weight of this interval
Ranges ranges; // the ranges in which this register is live
- bool isDefinedOnce; // True if this interval contains one value.
+
+ /// ValueNumberInfo - If the value number definition is undefined (e.g. phi
+ /// merge point), it contains ~0u,x. If the value number is not in use, it
+ /// contains ~1u,x to indicate that the value # is not used.
+ struct VNInfo {
+ unsigned def; // instruction # of the definition
+ unsigned reg; // src reg: non-zero iff val# is defined by a copy
+ SmallVector<unsigned, 4> kills; // instruction #s of the kills
+ VNInfo() : def(~1U), reg(0) {};
+ VNInfo(unsigned d, unsigned r) : def(d), reg(r) {};
+ };
+ private:
+ SmallVector<VNInfo, 4> ValueNumberInfo;
+ public:
LiveInterval(unsigned Reg, float Weight)
- : reg(Reg), weight(Weight), isDefinedOnce(false) {
+ : reg(Reg), preference(0), 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(); }
+
+
+ /// 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
+ /// LiveRange immediately after the hole.
+ iterator advanceTo(iterator I, unsigned Pos) {
+ if (Pos >= endNumber())
+ return end();
+ while (I->end <= Pos) ++I;
+ return I;
+ }
+
+ void swap(LiveInterval& other) {
+ std::swap(reg, other.reg);
+ std::swap(weight, other.weight);
+ std::swap(ranges, other.ranges);
+ std::swap(ValueNumberInfo, other.ValueNumberInfo);
}
- bool containsOneValue() const { return isDefinedOnce; }
+ bool containsOneValue() const { return ValueNumberInfo.size() == 1; }
+ unsigned getNumValNums() const { return ValueNumberInfo.size(); }
+
+ /// getNextValue - Create a new value number and return it. MIIdx specifies
+ /// the instruction that defines the value number.
+ unsigned getNextValue(unsigned MIIdx, unsigned SrcReg) {
+ ValueNumberInfo.push_back(VNInfo(MIIdx, SrcReg));
+ return ValueNumberInfo.size()-1;
+ }
+
+ /// getDefForValNum - Return the machine instruction index that defines the
+ /// specified value number.
+ unsigned getDefForValNum(unsigned ValNo) const {
+ assert(ValNo < ValueNumberInfo.size());
+ return ValueNumberInfo[ValNo].def;
+ }
+
+ /// getSrcRegForValNum - If the machine instruction that defines the
+ /// specified value number is a copy, returns the source register. Otherwise,
+ /// returns zero.
+ unsigned getSrcRegForValNum(unsigned ValNo) const {
+ assert(ValNo < ValueNumberInfo.size());
+ return ValueNumberInfo[ValNo].reg;
+ }
+
+ /// setDefForValNum - Set the machine instruction index that defines the
+ /// specified value number.
+ void setDefForValNum(unsigned ValNo, unsigned NewDef) {
+ assert(ValNo < ValueNumberInfo.size());
+ ValueNumberInfo[ValNo].def = NewDef;
+ }
+
+ /// setSrcRegForValNum - Set the source register of the specified value
+ /// number.
+ void setSrcRegForValNum(unsigned ValNo, unsigned NewReg) {
+ assert(ValNo < ValueNumberInfo.size());
+ ValueNumberInfo[ValNo].reg = NewReg;
+ }
+
+ /// getKillsForValNum - Return the kill instruction indexes of the specified
+ /// value number.
+ const SmallVector<unsigned, 4> &getKillsForValNum(unsigned ValNo) const {
+ assert(ValNo < ValueNumberInfo.size());
+ return ValueNumberInfo[ValNo].kills;
+ }
+
+ /// addKillForValNum - Add a kill instruction index to the specified value
+ /// number.
+ void addKillForValNum(unsigned ValNo, unsigned KillIdx) {
+ assert(ValNo < ValueNumberInfo.size());
+ SmallVector<unsigned, 4> &kills = ValueNumberInfo[ValNo].kills;
+ if (kills.empty()) {
+ kills.push_back(KillIdx);
+ } else {
+ SmallVector<unsigned, 4>::iterator
+ I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
+ kills.insert(I, KillIdx);
+ }
+ }
+
+ /// 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 SmallVector<unsigned, 4> &kills) {
+ for (unsigned i = 0, e = kills.size(); i != e; ++i) {
+ unsigned KillIdx = kills[i];
+ if (!liveAt(KillIdx)) {
+ SmallVector<unsigned, 4>::iterator
+ I = std::lower_bound(VNI.kills.begin(), VNI.kills.end(), KillIdx);
+ VNI.kills.insert(I, KillIdx);
+ }
+ }
+ }
+
+ /// addKillsForValNum - Add a number of kills into the kills vector of
+ /// the specified value number.
+ void addKillsForValNum(unsigned ValNo,
+ const SmallVector<unsigned, 4> &kills) {
+ addKills(ValueNumberInfo[ValNo], kills);
+ }
+
+ /// isKillForValNum - Returns true if KillIdx is a kill of the specified
+ /// val#.
+ bool isKillForValNum(unsigned ValNo, unsigned KillIdx) const {
+ assert(ValNo < ValueNumberInfo.size());
+ const SmallVector<unsigned, 4> &kills = ValueNumberInfo[ValNo].kills;
+ SmallVector<unsigned, 4>::const_iterator
+ I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
+ if (I == kills.end())
+ return false;
+ return *I == KillIdx;
+ }
+
+ /// removeKill - Remove the specified kill from the list of kills of
+ /// the specified val#.
+ static bool removeKill(VNInfo &VNI, unsigned KillIdx) {
+ SmallVector<unsigned, 4> &kills = VNI.kills;
+ SmallVector<unsigned, 4>::iterator
+ I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
+ if (I != kills.end() && *I == KillIdx) {
+ kills.erase(I);
+ return true;
+ }
+ return false;
+ }
+
+ /// removeKillForValNum - Remove the specified kill from the list of kills
+ /// of the specified val#.
+ bool removeKillForValNum(unsigned ValNo, unsigned KillIdx) {
+ assert(ValNo < ValueNumberInfo.size());
+ return removeKill(ValueNumberInfo[ValNo], KillIdx);
+ }
+
+ /// removeKillForValNum - Remove all the kills in specified range
+ /// [Start, End] of the specified val#.
+ void removeKillForValNum(unsigned ValNo, unsigned Start, unsigned End) {
+ assert(ValNo < ValueNumberInfo.size());
+ SmallVector<unsigned, 4> &kills = ValueNumberInfo[ValNo].kills;
+ SmallVector<unsigned, 4>::iterator
+ I = std::lower_bound(kills.begin(), kills.end(), Start);
+ SmallVector<unsigned, 4>::iterator
+ E = std::upper_bound(kills.begin(), kills.end(), End);
+ kills.erase(I, E);
+ }
+
+ /// replaceKill - Replace a kill index of the specified value# with a new
+ /// kill. Returns true if OldKill was indeed a kill point.
+ static bool replaceKill(VNInfo &VNI, unsigned OldKill, unsigned NewKill) {
+ SmallVector<unsigned, 4> &kills = VNI.kills;
+ SmallVector<unsigned, 4>::iterator
+ I = std::lower_bound(kills.begin(), kills.end(), OldKill);
+ if (I != kills.end() && *I == OldKill) {
+ *I = NewKill;
+ return true;
+ }
+ return false;
+ }
+
+ /// replaceKillForValNum - Replace a kill index of the specified value# with
+ /// a new kill. Returns true if OldKill was indeed a kill point.
+ bool replaceKillForValNum(unsigned ValNo, unsigned OldKill,
+ unsigned NewKill) {
+ assert(ValNo < ValueNumberInfo.size());
+ return replaceKill(ValueNumberInfo[ValNo], OldKill, NewKill);
+ }
+
+ /// getValNumInfo - Returns a copy of the specified val#.
+ ///
+ VNInfo getValNumInfo(unsigned ValNo) const {
+ assert(ValNo < ValueNumberInfo.size());
+ return ValueNumberInfo[ValNo];
+ }
+
+ /// setValNumInfo - Change the value number info for the specified
+ /// value number.
+ void setValNumInfo(unsigned ValNo, const VNInfo &I) {
+ ValueNumberInfo[ValNo] = I;
+ }
+
+ /// copyValNumInfo - Copy the value number info for one value number to
+ /// another.
+ void copyValNumInfo(unsigned DstValNo, unsigned SrcValNo) {
+ ValueNumberInfo[DstValNo] = ValueNumberInfo[SrcValNo];
+ }
+ void copyValNumInfo(unsigned DstValNo, const LiveInterval &SrcLI,
+ unsigned SrcValNo) {
+ ValueNumberInfo[DstValNo] = SrcLI.ValueNumberInfo[SrcValNo];
+ }
+
+ /// 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.
+ void MergeValueNumberInto(unsigned V1, unsigned 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.
+ void MergeInClobberRanges(const LiveInterval &Clobbers);
+
+
+ /// MergeRangesInAsValue - Merge all of the intervals 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 MergeRangesInAsValue(const LiveInterval &RHS, unsigned LHSValNo);
+
bool empty() const { return ranges.empty(); }
- /// start - Return the lowest numbered slot covered by interval.
- unsigned start() const {
+ /// beginNumber - Return the lowest numbered slot covered by interval.
+ unsigned beginNumber() const {
assert(!empty() && "empty interval for register");
return ranges.front().start;
}
- /// end - return the maximum point of the interval of the whole,
+ /// endNumber - return the maximum point of the interval of the whole,
/// exclusive.
- unsigned end() const {
+ unsigned endNumber() const {
assert(!empty() && "empty interval for register");
return ranges.back().end;
}
bool expiredAt(unsigned index) const {
- return end() <= (index + 1);
+ return index >= endNumber();
}
bool liveAt(unsigned index) const;
- bool overlaps(const LiveInterval& other) const;
+ /// getLiveRangeContaining - Return the live range that contains the
+ /// specified index, or null if there is none.
+ const LiveRange *getLiveRangeContaining(unsigned Idx) const {
+ const_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(unsigned Idx) const;
+
+ /// FindLiveRangeContaining - Return an iterator to the live range that
+ /// contains the specified index, or end() if there is none.
+ iterator FindLiveRangeContaining(unsigned Idx);
+
+ /// 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);
+
+ /// 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());
+ }
+
+ /// 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
addRangeFrom(LR, ranges.begin());
}
- void join(const LiveInterval& other);
+ /// 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, int *ValNoAssignments,
+ int *RHSValNoAssignments,
+ SmallVector<VNInfo,16> &NewValueNumberInfo);
+
+ /// 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);
+
+ void removeRange(LiveRange LR) {
+ removeRange(LR.start, LR.end);
+ }
+
+ /// getSize - Returns the sum of sizes of all the LiveRange's.
+ ///
+ unsigned getSize() const;
bool operator<(const LiveInterval& other) const {
- return start() < other.start();
+ return beginNumber() < other.beginNumber();
}
- bool operator==(const LiveInterval& other) const {
- return reg == other.reg;
+ void print(std::ostream &OS, const MRegisterInfo *MRI = 0) const;
+ void print(std::ostream *OS, const MRegisterInfo *MRI = 0) const {
+ if (OS) print(*OS, MRI);
}
+ 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);
+ LiveInterval& operator=(const LiveInterval& rhs); // DO NOT IMPLEMENT
};
- std::ostream& operator<<(std::ostream& os, const LiveInterval& li);
+ inline std::ostream &operator<<(std::ostream &OS, const LiveInterval &LI) {
+ LI.print(OS);
+ return OS;
+ }
}
#endif
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