Add support for updating the LiveIntervals of registers used by 'exotic'
terminators that actually have register uses when splitting critical edges.
This commit also introduces a method repairIntervalsInRange() on LiveIntervals,
which allows for repairing LiveIntervals in a small range after an arbitrary
target hook modifies, inserts, and removes instructions. It's pretty limited
right now, but I hope to extend it to support all of the things that are done
by the convertToThreeAddress() target hooks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175382 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 0d4ec11..3c67be5 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1032,3 +1032,39 @@
HMEditor HME(*this, *MRI, *TRI, OldIndex, NewIndex, UpdateFlags);
HME.updateAllRanges(MI);
}
+
+void
+LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB,
+ MachineBasicBlock::reverse_iterator RBegin,
+ MachineBasicBlock::reverse_iterator REnd,
+ SmallVectorImpl<unsigned> &OrigRegs) {
+ for (unsigned i = 0, e = OrigRegs.size(); i != e; ++i) {
+ unsigned Reg = OrigRegs[i];
+ if (!TargetRegisterInfo::isVirtualRegister(Reg))
+ continue;
+
+ LiveInterval &LI = getInterval(Reg);
+ SlotIndex startIdx = (REnd == MBB->rend()) ? getMBBStartIdx(MBB)
+ : getInstructionIndex(&*REnd);
+ for (MachineBasicBlock::reverse_iterator I = RBegin; I != REnd; ++I) {
+ MachineInstr *MI = &*I;
+ SlotIndex instrIdx = getInstructionIndex(MI);
+
+ for (MachineInstr::mop_iterator OI = MI->operands_begin(),
+ OE = MI->operands_end(); OI != OE; ++OI) {
+ const MachineOperand &MO = *OI;
+ if (!MO.isReg() || MO.getReg() != Reg)
+ continue;
+
+ assert(MO.isUse() && "Register defs are not yet supported.");
+
+ if (!LI.liveAt(instrIdx)) {
+ LiveRange *LR = LI.getLiveRangeContaining(startIdx.getRegSlot());
+ assert(LR && "Used registers must be live-in.");
+ LR->end = instrIdx.getRegSlot();
+ break;
+ }
+ }
+ }
+ }
+}
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index df1c7c2..3d75436 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -698,6 +698,24 @@
}
}
+ SmallVector<unsigned, 4> UsedRegs;
+ if (LIS) {
+ for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
+ I != E; ++I) {
+ MachineInstr *MI = I;
+
+ for (MachineInstr::mop_iterator OI = MI->operands_begin(),
+ OE = MI->operands_end(); OI != OE; ++OI) {
+ if (!OI->isReg() || OI->getReg() == 0)
+ continue;
+
+ unsigned Reg = OI->getReg();
+ if (std::find(UsedRegs.begin(), UsedRegs.end(), Reg) == UsedRegs.end())
+ UsedRegs.push_back(Reg);
+ }
+ }
+ }
+
ReplaceUsesOfBlockWith(Succ, NMBB);
// If updateTerminator() removes instructions, we need to remove them from
@@ -830,6 +848,17 @@
LI.removeRange(StartIndex, EndIndex);
}
}
+
+ // Update all intervals for registers whose uses may have been modified by
+ // updateTerminator().
+ iterator FirstTerminator = getFirstTerminator();
+ MachineInstr *FirstTerminatorMI = FirstTerminator;
+ if (FirstTerminatorMI->isBundled())
+ FirstTerminatorMI = getBundleStart(FirstTerminatorMI);
+ reverse_iterator PreTerminators =
+ (FirstTerminator == begin()) ? rend()
+ : reverse_iterator(FirstTerminatorMI);
+ LIS->repairIntervalsInRange(this, rbegin(), PreTerminators, UsedRegs);
}
if (MachineDominatorTree *MDT =