//
// 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 "llvm/Support/Allocator.h"
#include <iosfwd>
-#include <vector>
#include <cassert>
namespace llvm {
- class MRegisterInfo;
+ class MachineInstr;
+ class TargetRegisterInfo;
+ struct LiveInterval;
+
+ /// VNInfo - 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.
+ /// def - Instruction # of the definition.
+ /// - or reg # of the definition if it's a stack slot liveinterval.
+ /// copy - Copy iff val# is defined by a copy; zero otherwise.
+ /// hasPHIKill - One or more of the kills are PHI nodes.
+ /// redefByEC - Re-defined by early clobber somewhere during the live range.
+ /// kills - Instruction # of the kills.
+ struct VNInfo {
+ unsigned id;
+ unsigned def;
+ MachineInstr *copy;
+ bool hasPHIKill : 1;
+ bool redefByEC : 1;
+ SmallVector<unsigned, 4> kills;
+ VNInfo()
+ : id(~1U), def(~1U), copy(0), hasPHIKill(false), redefByEC(false) {}
+ VNInfo(unsigned i, unsigned d, MachineInstr *c)
+ : id(i), def(d), copy(c), hasPHIKill(false), redefByEC(false) {}
+ };
/// LiveRange structure - This represents a simple register range in the
/// program, with an inclusive start point and an exclusive end point.
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.
+ VNInfo *valno; // identifier for the value contained in this interval.
- LiveRange(unsigned S, unsigned E, unsigned V) : start(S), end(E), ValId(V) {
+ LiveRange(unsigned S, unsigned E, VNInfo *V) : start(S), end(E), valno(V) {
assert(S < E && "Cannot create empty or backwards range");
}
}
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;
}
/// state.
struct LiveInterval {
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
+ unsigned short preference; // preferred register for this interval
Ranges ranges; // the ranges in which this register is live
- private:
- unsigned NumValues; // the number of distinct values in this interval.
-
- /// InstDefiningValue - This tracks the def index of the instruction that
- /// defines a particular value number in the interval. This may be ~0,
- /// which is treated as unknown, or ~1, which is a deleted value number.
- SmallVector<unsigned, 4> InstDefiningValue;
- public:
+ VNInfoList valnos; // value#'s
- LiveInterval(unsigned Reg, float Weight)
- : reg(Reg), weight(Weight), NumValues(0) {
+ public:
+ LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
+ : reg(Reg), weight(Weight), preference(0) {
+ if (IsSS)
+ reg = reg | (1U << (sizeof(unsigned)*8-1));
}
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
while (I->end <= Pos) ++I;
return I;
}
+
+ void clear() {
+ while (!valnos.empty()) {
+ VNInfo *VNI = valnos.back();
+ valnos.pop_back();
+ VNI->~VNInfo();
+ }
+
+ ranges.clear();
+ }
+
+ /// isStackSlot - Return true if this is a stack slot interval.
+ ///
+ bool isStackSlot() const {
+ return reg & (1U << (sizeof(unsigned)*8-1));
+ }
- void swap(LiveInterval& other) {
- std::swap(reg, other.reg);
- std::swap(weight, other.weight);
- std::swap(ranges, other.ranges);
- std::swap(NumValues, other.NumValues);
- std::swap(InstDefiningValue, other.InstDefiningValue);
+ /// 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)*8-1));
}
- bool containsOneValue() const { return NumValues == 1; }
+ bool hasAtLeastOneValue() const { return !valnos.empty(); }
+
+ bool containsOneValue() const { return valnos.size() == 1; }
- unsigned getNumValNums() const { return NumValues; }
+ 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];
+ }
+ /// copyValNumInfo - Copy the value number info for one value number to
+ /// another.
+ void copyValNumInfo(VNInfo *DstValNo, const VNInfo *SrcValNo) {
+ DstValNo->def = SrcValNo->def;
+ DstValNo->copy = SrcValNo->copy;
+ DstValNo->hasPHIKill = SrcValNo->hasPHIKill;
+ DstValNo->redefByEC = SrcValNo->redefByEC;
+ DstValNo->kills = SrcValNo->kills;
+ }
+
/// getNextValue - Create a new value number and return it. MIIdx specifies
/// the instruction that defines the value number.
- unsigned getNextValue(unsigned MIIdx) {
- InstDefiningValue.push_back(MIIdx);
- return NumValues++;
+ VNInfo *getNextValue(unsigned MIIdx, MachineInstr *CopyMI,
+ BumpPtrAllocator &VNInfoAllocator) {
+#ifdef __GNUC__
+ unsigned Alignment = (unsigned)__alignof__(VNInfo);
+#else
+ // FIXME: ugly.
+ unsigned Alignment = 8;
+#endif
+ VNInfo *VNI =
+ static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
+ Alignment));
+ new (VNI) VNInfo((unsigned)valnos.size(), MIIdx, CopyMI);
+ valnos.push_back(VNI);
+ return VNI;
}
-
- /// getInstForValNum - Return the machine instruction index that defines the
- /// specified value number.
- unsigned getInstForValNum(unsigned ValNo) const {
- return InstDefiningValue[ValNo];
+
+ /// addKill - Add a kill instruction index to the specified value
+ /// number.
+ static void addKill(VNInfo *VNI, unsigned KillIdx) {
+ SmallVector<unsigned, 4> &kills = VNI->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);
+ }
}
-
- /// setInstDefiningValNum - Change the instruction defining the specified
- /// value number to the specified instruction.
- void setInstDefiningValNum(unsigned ValNo, unsigned MIIdx) {
- InstDefiningValue[ValNo] = MIIdx;
+
+ /// 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 = static_cast<unsigned>(kills.size());
+ i != e; ++i) {
+ unsigned KillIdx = kills[i];
+ if (!liveBeforeAndAt(KillIdx)) {
+ SmallVector<unsigned, 4>::iterator
+ I = std::lower_bound(VNI->kills.begin(), VNI->kills.end(), KillIdx);
+ VNI->kills.insert(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;
+ }
+
+ /// removeKills - Remove all the kills in specified range
+ /// [Start, End] of the specified val#.
+ static void removeKills(VNInfo *VNI, unsigned Start, unsigned End) {
+ SmallVector<unsigned, 4> &kills = VNI->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);
+ }
+
+ /// isKill - Return true if the specified index is a kill of the
+ /// specified val#.
+ static bool isKill(const VNInfo *VNI, unsigned KillIdx) {
+ const SmallVector<unsigned, 4> &kills = VNI->kills;
+ SmallVector<unsigned, 4>::const_iterator
+ I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
+ return I != kills.end() && *I == KillIdx;
+ }
+
+ /// 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.
- void MergeValueNumberInto(unsigned V1, unsigned V2);
-
+ 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(const LiveInterval &Clobbers,
+ BumpPtrAllocator &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, BumpPtrAllocator &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");
+ if (empty())
+ return 0;
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");
+ if (empty())
+ return 0;
return ranges.back().end;
}
bool liveAt(unsigned 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(unsigned index) const;
+
/// getLiveRangeContaining - Return the live range that contains the
/// specified index, or null if there is none.
const LiveRange *getLiveRangeContaining(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);
-
- /// 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;
-
- /// 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 at the specified
+ /// index (register interval) or defined by the specified register (stack
+ /// inteval).
+ VNInfo *findDefinedVNInfo(unsigned DefIdxOrReg) const;
+
/// overlaps - Return true if the intersection of the two live intervals is
/// not empty.
bool overlaps(const LiveInterval& other) const {
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);
+ /// isInOneLiveRange - Return true if the range specified is entirely in the
+ /// a single LiveRange of the live interval.
+ bool isInOneLiveRange(unsigned Start, unsigned 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(unsigned Start, unsigned 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;
bool operator<(const LiveInterval& other) const {
return beginNumber() < other.beginNumber();
}
- void print(std::ostream &OS, const MRegisterInfo *MRI = 0) const;
+ void print(std::ostream &OS, const TargetRegisterInfo *TRI = 0) const;
+ void print(std::ostream *OS, const TargetRegisterInfo *TRI = 0) const {
+ if (OS) print(*OS, TRI);
+ }
void dump() const;
private:
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