vendor/llvm/llvm-r72732

1 files changed, 468 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
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+++ b/include/llvm/CodeGen/LiveInterval.h
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+//===-- 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/SmallVector.h"
+#include "llvm/Support/Allocator.h"
+#include <iosfwd>
+#include <cassert>
+#include <climits>
+
+namespace llvm {
+  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.
+  /// 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)
+    VNInfo *valno;   // identifier for the value contained in this interval.
+
+    LiveRange(unsigned S, unsigned 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(unsigned I) const {
+      return start <= I && I < 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(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 SmallVector<LiveRange,4> Ranges;
+    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
+    VNInfoList valnos;   // value#'s
+
+  public:
+    
+    struct InstrSlots {
+      enum {
+        LOAD  = 0,
+        USE   = 1,
+        DEF   = 2,
+        STORE = 3,
+        NUM   = 4
+      };
+
+      static unsigned scale(unsigned slot, unsigned factor) {
+        unsigned index = slot / NUM,
+                 offset = slot % NUM;
+        assert(index <= ~0U / (factor * NUM) &&
+               "Rescaled interval would overflow");
+        return index * NUM * factor + offset;
+      }
+
+    };
+
+    LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
+      : reg(Reg), weight(Weight), preference(0)  {
+      if (IsSS)
+        reg = reg | (1U << (sizeof(unsigned)*CHAR_BIT-1));
+    }
+
+    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 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 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)*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];
+    }
+    
+    /// 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.
+    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;
+    }
+
+    /// 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);
+      }
+    }
+
+    /// 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.
+    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);
+
+    /// MergeInClobberRange - Same as MergeInClobberRanges except it merge in a
+    /// single LiveRange only.
+    void MergeInClobberRange(unsigned Start, unsigned End,
+                             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 {
+      if (empty())
+        return 0;
+      return ranges.front().start;
+    }
+
+    /// endNumber - return the maximum point of the interval of the whole,
+    /// exclusive.
+    unsigned endNumber() const {
+      if (empty())
+        return 0;
+      return ranges.back().end;
+    }
+
+    bool expiredAt(unsigned index) const {
+      return index >= endNumber();
+    }
+
+    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 {
+      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);
+
+    /// 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 {
+      return overlapsFrom(other, other.begin());
+    }
+
+    /// overlaps - Return true if the live interval overlaps a range specified
+    /// by [Start, End).
+    bool overlaps(unsigned Start, unsigned 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.
+    void addRange(LiveRange LR) {
+      addRangeFrom(LR, ranges.begin());
+    }
+
+    /// 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 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);
+
+    /// 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;
+
+    bool operator<(const LiveInterval& other) const {
+      return beginNumber() < other.beginNumber();
+    }
+
+    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:
+    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
+  };
+
+  inline std::ostream &operator<<(std::ostream &OS, const LiveInterval &LI) {
+    LI.print(OS);
+    return OS;
+  }
+}
+
+#endif