namespace llvm {
class MachineInstr;
+ class MachineRegisterInfo;
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 {
+ /// 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 the def index does not
+ /// actually point to the defining MachineInstr, or even (necessarily) a
+ /// valid MachineInstr at all. In general such a def index should not be
+ /// used as an index to obtain a MachineInstr. The exception is Values
+ /// defined by PHI instructions, after PHI elimination has occured. In this
+ /// case the def should point to the start of the block in which the PHI
+ /// existed. This fact can be used to insert code dealing with the PHI value
+ /// at the merge point (e.g. to spill or split it).
+
+ class VNInfo {
+ private:
+ static const uint8_t HAS_PHI_KILL = 1,
+ REDEF_BY_EC = 1 << 1,
+ IS_PHI_DEF = 1 << 2,
+ IS_UNUSED = 1 << 3,
+ IS_DEF_ACCURATE = 1 << 4;
+
+ uint8_t flags;
+
+ public:
+ /// The ID number of this value.
unsigned id;
+
+ /// The index of the defining instruction (if isDefAccurate() returns true).
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) {}
+ : flags(IS_UNUSED), id(~1U), def(0), 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, unsigned d, MachineInstr *c)
- : id(i), def(d), copy(c), hasPHIKill(false), redefByEC(false) {}
+ : flags(IS_DEF_ACCURATE), id(i), def(d), copy(c) {}
+
+ /// VNInfo construtor, copies values from orig, except for the value number.
+ VNInfo(unsigned i, const VNInfo &orig)
+ : flags(orig.flags), id(i), def(orig.def), copy(orig.copy),
+ kills(orig.kills) {}
+
+ /// Used for copying value number info.
+ unsigned getFlags() const { return flags; }
+ void setFlags(unsigned flags) { this->flags = flags; }
+
+ /// Returns true if one or more kills are PHI nodes.
+ bool hasPHIKill() const { return flags & HAS_PHI_KILL; }
+ 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; }
+ 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; }
+ 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; }
+ 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; }
+ void setIsDefAccurate(bool defAccurate) {
+ if (defAccurate)
+ flags |= IS_DEF_ACCURATE;
+ else
+ flags &= ~IS_DEF_ACCURATE;
+ }
+
};
/// LiveRange structure - This represents a simple register range in the
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) {
+ : reg(Reg), weight(Weight) {
if (IsSS)
reg = reg | (1U << (sizeof(unsigned)*CHAR_BIT-1));
}
void copyValNumInfo(VNInfo *DstValNo, const VNInfo *SrcValNo) {
DstValNo->def = SrcValNo->def;
DstValNo->copy = SrcValNo->copy;
- DstValNo->hasPHIKill = SrcValNo->hasPHIKill;
- DstValNo->redefByEC = SrcValNo->redefByEC;
+ DstValNo->setFlags(SrcValNo->getFlags());
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) {
+ bool isDefAccurate, BumpPtrAllocator &VNInfoAllocator) {
+
+ assert(MIIdx != ~0u && MIIdx != ~1u &&
+ "PHI def / unused flags should now be passed explicitly.");
#ifdef __GNUC__
unsigned Alignment = (unsigned)__alignof__(VNInfo);
#else
static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
Alignment));
new (VNI) VNInfo((unsigned)valnos.size(), MIIdx, CopyMI);
+ VNI->setIsDefAccurate(isDefAccurate);
valnos.push_back(VNI);
return VNI;
}
- /// getUnknownValNo - Find a value# for unknown values, if there isn't one
- /// create a new one.
- VNInfo *getUnknownValNo(BumpPtrAllocator &VNInfoAllocator);
+ /// 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) {
+
+#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(), *orig);
+ valnos.push_back(VNI);
+ return VNI;
+ }
/// addKill - Add a kill instruction index to the specified value
/// number.
/// 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);
+ void Copy(const LiveInterval &RHS, MachineRegisterInfo *MRI,
+ BumpPtrAllocator &VNInfoAllocator);
bool empty() const { return ranges.empty(); }
/// the intervals are not joinable, this aborts.
void join(LiveInterval &Other, const int *ValNoAssignments,
const int *RHSValNoAssignments,
- SmallVector<VNInfo*, 16> &NewVNInfo);
+ SmallVector<VNInfo*, 16> &NewVNInfo,
+ MachineRegisterInfo *MRI);
/// isInOneLiveRange - Return true if the range specified is entirely in the
/// a single LiveRange of the live interval.
/// 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;
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