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-rw-r--r--include/llvm/CodeGen/LiveInterval.h25
-rw-r--r--lib/CodeGen/LiveInterval.cpp16
-rw-r--r--lib/CodeGen/LiveIntervalAnalysis.cpp41
3 files changed, 63 insertions, 19 deletions
diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
index 183cd9abc9..30a397b22f 100644
--- a/include/llvm/CodeGen/LiveInterval.h
+++ b/include/llvm/CodeGen/LiveInterval.h
@@ -79,6 +79,11 @@ namespace llvm {
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.
+ SmallVector<unsigned, 4> InstDefiningValue;
public:
LiveInterval(unsigned Reg, float Weight)
@@ -109,15 +114,31 @@ namespace llvm {
void swap(LiveInterval& other) {
std::swap(reg, other.reg);
std::swap(weight, other.weight);
- ranges.swap(other.ranges);
+ std::swap(ranges, other.ranges);
std::swap(NumValues, other.NumValues);
}
bool containsOneValue() const { return NumValues == 1; }
- unsigned getNextValue() {
+ /// 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++;
}
+
+ /// getInstForValNum - Return the machine instruction index that defines the
+ /// specified value number.
+ unsigned getInstForValNum(unsigned ValNo) const {
+ return InstDefiningValue[ValNo];
+ }
+
+ /// setInstDefiningValNum - Change the instruction defining the specified
+ /// value number to the specified instruction.
+ void setInstDefiningValNum(unsigned ValNo, unsigned MIIdx) {
+ InstDefiningValue[ValNo] = MIIdx;
+ }
+
bool empty() const { return ranges.empty(); }
diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index b0f09297b3..0a2483e481 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -388,7 +388,7 @@ void LiveInterval::join(LiveInterval &Other, unsigned CopyIdx) {
I->ValId = MergedDstValIdx;
else {
unsigned &NV = Dst2SrcIdxMap[I->ValId];
- if (NV == 0) NV = getNextValue();
+ if (NV == 0) NV = getNextValue(Other.getInstForValNum(I->ValId));
I->ValId = NV;
}
@@ -422,6 +422,20 @@ void LiveInterval::print(std::ostream &OS, const MRegisterInfo *MRI) const {
E = ranges.end(); I != E; ++I)
OS << *I;
}
+
+ // Print value number info.
+ if (NumValues) {
+ OS << " ";
+ for (unsigned i = 0; i != NumValues; ++i) {
+ if (i) OS << " ";
+ OS << i << "@";
+ if (InstDefiningValue[i] == ~0U) {
+ OS << "?";
+ } else {
+ OS << InstDefiningValue[i];
+ }
+ }
+ }
}
void LiveInterval::dump() const {
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index e5128558e3..e9bdaa11c8 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -328,7 +328,7 @@ addIntervalsForSpills(const LiveInterval &li, VirtRegMap &vrm, int slot) {
// the spill weight is now infinity as it
// cannot be spilled again
nI.weight = float(HUGE_VAL);
- LiveRange LR(start, end, nI.getNextValue());
+ LiveRange LR(start, end, nI.getNextValue(~0U));
DEBUG(std::cerr << " +" << LR);
nI.addRange(LR);
added.push_back(&nI);
@@ -351,18 +351,16 @@ addIntervalsForSpills(const LiveInterval &li, VirtRegMap &vrm, int slot) {
return added;
}
-void LiveIntervals::printRegName(unsigned reg) const
-{
+void LiveIntervals::printRegName(unsigned reg) const {
if (MRegisterInfo::isPhysicalRegister(reg))
std::cerr << mri_->getName(reg);
else
std::cerr << "%reg" << reg;
}
-void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
+void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
MachineBasicBlock::iterator mi,
- LiveInterval& interval)
-{
+ LiveInterval &interval) {
DEBUG(std::cerr << "\t\tregister: "; printRegName(interval.reg));
LiveVariables::VarInfo& vi = lv_->getVarInfo(interval.reg);
@@ -374,7 +372,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
// Get the Idx of the defining instructions.
unsigned defIndex = getDefIndex(getInstructionIndex(mi));
- unsigned ValNum = interval.getNextValue();
+ unsigned ValNum = interval.getNextValue(defIndex);
assert(ValNum == 0 && "First value in interval is not 0?");
ValNum = 0; // Clue in the optimizer.
@@ -456,10 +454,22 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
unsigned RedefIndex = getDefIndex(getInstructionIndex(mi));
// Delete the initial value, which should be short and continuous,
- // becuase the 2-addr copy must be in the same MBB as the redef.
+ // because the 2-addr copy must be in the same MBB as the redef.
interval.removeRange(DefIndex, RedefIndex);
- LiveRange LR(DefIndex, RedefIndex, interval.getNextValue());
+ // Two-address vregs should always only be redefined once. This means
+ // that at this point, there should be exactly one value number in it.
+ assert(interval.containsOneValue() && "Unexpected 2-addr liveint!");
+
+ // The new value number is defined by the instruction we claimed defined
+ // value #0.
+ unsigned ValNo = interval.getNextValue(DefIndex);
+
+ // Value#1 is now defined by the 2-addr instruction.
+ interval.setInstDefiningValNum(0, RedefIndex);
+
+ // Add the new live interval which replaces the range for the input copy.
+ LiveRange LR(DefIndex, RedefIndex, ValNo);
DEBUG(std::cerr << " replace range with " << LR);
interval.addRange(LR);
@@ -487,8 +497,9 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
interval.removeRange(Start, End);
DEBUG(std::cerr << "RESULT: " << interval);
- // Replace the interval with one of a NEW value number.
- LiveRange LR(Start, End, interval.getNextValue());
+ // Replace the interval with one of a NEW value number. Note that this
+ // value number isn't actually defined by an instruction, weird huh? :)
+ LiveRange LR(Start, End, interval.getNextValue(~0U));
DEBUG(std::cerr << " replace range with " << LR);
interval.addRange(LR);
DEBUG(std::cerr << "RESULT: " << interval);
@@ -500,7 +511,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
unsigned defIndex = getDefIndex(getInstructionIndex(mi));
LiveRange LR(defIndex,
getInstructionIndex(&mbb->back()) + InstrSlots::NUM,
- interval.getNextValue());
+ interval.getNextValue(defIndex));
interval.addRange(LR);
DEBUG(std::cerr << " +" << LR);
}
@@ -513,8 +524,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator mi,
LiveInterval& interval,
unsigned SrcReg, unsigned DestReg,
- bool isLiveIn)
-{
+ bool isLiveIn) {
// A physical register cannot be live across basic block, so its
// lifetime must end somewhere in its defining basic block.
DEBUG(std::cerr << "\t\tregister: "; printRegName(interval.reg));
@@ -591,8 +601,7 @@ exit:
}
}
-
- LiveRange LR(start, end, interval.getNextValue());
+ LiveRange LR(start, end, interval.getNextValue(start));
interval.addRange(LR);
DEBUG(std::cerr << " +" << LR << '\n');
}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-05-03 19:59:00 +0000