#ifndef LLVM_CODEGEN_LIVEINTERVAL_H
#define LLVM_CODEGEN_LIVEINTERVAL_H
-#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/IntEqClasses.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/AlignOf.h"
#include "llvm/CodeGen/SlotIndexes.h"
/// 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,
+ HAS_PHI_KILL = 1,
REDEF_BY_EC = 1 << 1,
IS_PHI_DEF = 1 << 2,
- IS_UNUSED = 1 << 3,
- IS_DEF_ACCURATE = 1 << 4
+ IS_UNUSED = 1 << 3
};
+ MachineInstr *copy;
unsigned char flags;
- union {
- MachineInstr *copy;
- unsigned reg;
- } cr;
public:
-
- typedef SmallVector<SlotIndex, 4> KillSet;
+ typedef BumpPtrAllocator Allocator;
/// 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; }
+ : copy(c), flags(0), id(i), def(d)
+ { }
/// 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(orig.copy), flags(orig.flags), id(i), def(orig.def)
{ }
/// Copy from the parameter into this VNInfo.
void copyFrom(VNInfo &src) {
flags = src.flags;
- cr = src.cr;
+ copy = src.copy;
def = src.def;
- kills = src.kills;
}
/// Used for copying value number info.
unsigned getFlags() const { return flags; }
void setFlags(unsigned flags) { this->flags = flags; }
+ /// Merge flags from another VNInfo
+ void mergeFlags(const VNInfo *VNI) {
+ flags = (flags | VNI->flags) & ~IS_UNUSED;
+ }
+
/// 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; }
+ MachineInstr* getCopy() const { return 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; }
+ void setCopy(MachineInstr *c) { copy = c; }
+
+ /// isDefByCopy - Return true when this value was defined by a copy-like
+ /// instruction as determined by MachineInstr::isCopyLike.
+ bool isDefByCopy() const { return copy != 0; }
/// Returns true if one or more kills are PHI nodes.
bool hasPHIKill() const { return flags & HAS_PHI_KILL; }
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; }
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
}
/// containsRange - Return true if the given range, [S, E), is covered by
- /// this range.
+ /// this range.
bool containsRange(SlotIndex S, SlotIndex E) const {
assert((S < E) && "Backwards interval?");
return (start <= S && S < end) && (start < E && E <= end);
LiveRange(); // DO NOT IMPLEMENT
};
+ template <> struct isPodLike<LiveRange> { static const bool value = true; };
+
raw_ostream& operator<<(raw_ostream& os, const LiveRange &LR);
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.
+ 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,
};
- LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
- : reg(Reg), weight(Weight) {
- if (IsSS)
- reg = reg | (1U << (sizeof(unsigned)*CHAR_BIT-1));
- }
+ LiveInterval(unsigned Reg, float Weight)
+ : reg(Reg), weight(Weight) {}
typedef Ranges::iterator iterator;
iterator begin() { return ranges.begin(); }
/// 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, SlotIndex Pos) {
+ assert(I != end());
if (Pos >= endIndex())
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.
+ /// 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.
///
- bool isStackSlot() const {
- return reg & (1U << (sizeof(unsigned)*CHAR_BIT-1));
+ /// 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);
}
- /// 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));
+ 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];
}
+ /// 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, MachineInstr *CopyMI,
- bool isDefAccurate, BumpPtrAllocator &VNInfoAllocator){
+ VNInfo::Allocator &VNInfoAllocator) {
VNInfo *VNI =
- static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
- alignof<VNInfo>()));
- new (VNI) VNInfo((unsigned)valnos.size(), def, CopyMI);
- VNI->setIsDefAccurate(isDefAccurate);
+ new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), def, CopyMI);
valnos.push_back(VNI);
return VNI;
}
/// Create a copy of the given value. The new value will be identical except
/// for the Value number.
VNInfo *createValueCopy(const VNInfo *orig,
- BumpPtrAllocator &VNInfoAllocator) {
+ VNInfo::Allocator &VNInfoAllocator) {
VNInfo *VNI =
- static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
- alignof<VNInfo>()));
-
- new (VNI) VNInfo((unsigned)valnos.size(), *orig);
+ new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), *orig);
valnos.push_back(VNI);
return VNI;
}
- /// 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]);
- }
- }
- }
+ /// RenumberValues - Renumber all values in order of appearance and remove
+ /// unused values.
+ /// Recalculate phi-kill flags in case any phi-def values were removed.
+ void RenumberValues(LiveIntervals &lis);
/// isOnlyLROfValNo - Return true if the specified live range is the only
/// one defined by the its val#.
}
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,
- BumpPtrAllocator &VNInfoAllocator);
-
- /// MergeInClobberRange - Same as MergeInClobberRanges except it merge in a
- /// single LiveRange only.
- void MergeInClobberRange(LiveIntervals &li_,
- SlotIndex Start,
- SlotIndex 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
/// 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,
- BumpPtrAllocator &VNInfoAllocator);
-
+ VNInfo::Allocator &VNInfoAllocator);
+
bool empty() const { return ranges.empty(); }
/// beginIndex - Return the lowest numbered slot covered by interval.
return index >= endIndex();
}
- bool liveAt(SlotIndex index) const;
+ bool liveAt(SlotIndex index) const {
+ const_iterator r = find(index);
+ return r != end() && r->start <= index;
+ }
- // 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;
+ /// 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.getUseIndex());
+ return r != end() && r->end == index;
+ }
+
+ /// killedInRange - Return true if the interval has kills in [Start,End).
+ /// Note that the kill point is considered the end of a live range, so it is
+ /// not contained in the live range. If a live range ends at End, it won't
+ /// be counted as a kill by this method.
+ bool killedInRange(SlotIndex Start, SlotIndex End) const;
/// getLiveRangeContaining - Return the live range that contains the
/// specified index, or null if there is none.
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;
+ /// 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;
+ }
/// FindLiveRangeContaining - Return an iterator to the live range that
/// contains the specified index, or end() if there is none.
- iterator FindLiveRangeContaining(SlotIndex Idx);
+ 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();
+ }
/// findDefinedVNInfo - Find the by the specified
- /// index (register interval) or defined
+ /// index (register interval) or defined
VNInfo *findDefinedVNInfoForRegInt(SlotIndex Idx) const;
- /// 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 {
+ if (other.empty())
+ return false;
return overlapsFrom(other, other.begin());
}
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.
/// isInOneLiveRange - Return true if the range specified is entirely in the
/// a single LiveRange of the live interval.
- bool isInOneLiveRange(SlotIndex Start, SlotIndex End);
+ 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.
/// 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;
+ /// 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;
+ }
+
/// ComputeJoinedWeight - Set the weight of a live interval after
/// Other has been merged into it.
void ComputeJoinedWeight(const LiveInterval &Other);
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); // DO NOT IMPLEMENT
LI.print(OS);
return OS;
}
-}
+ /// 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
projects / oota-llvm.git / blobdiff