Changes in directory llvm/lib/CodeGen:
LiveIntervalAnalysis.cpp updated: 1.216 -> 1.217
---
Log message:
Track all joined registers and eliminate unneeded kills after all joining are
done.
---
Diffs of the changes: (+42 -22)
LiveIntervalAnalysis.cpp | 64 ++++++++++++++++++++++++++++++-----------------
1 files changed, 42 insertions(+), 22 deletions(-)
Index: llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
diff -u llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.216
llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.217
--- llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.216 Mon Feb 26 15:36:03 2007
+++ llvm/lib/CodeGen/LiveIntervalAnalysis.cpp Wed Feb 28 20:03:03 2007
@@ -65,6 +65,7 @@
i2miMap_.clear();
r2iMap_.clear();
r2rMap_.clear();
+ JoinedLIs.clear();
}
@@ -987,27 +988,11 @@
DOUT << "\n\t\tJoined. Result = "; DestInt.print(DOUT, mri_);
DOUT << "\n";
- // Live range has been lengthened due to colaescing, eliminate the
- // unnecessary kills at the end of the source live ranges.
- LiveVariables::VarInfo& svi = lv_->getVarInfo(repSrcReg);
- for (unsigned i = 0, e = svi.Kills.size(); i != e; ++i) {
- MachineInstr *Kill = svi.Kills[i];
- if (Kill == CopyMI || isRemoved(Kill))
- continue;
- if (DestInt.liveAt(getInstructionIndex(Kill) + InstrSlots::NUM))
- unsetRegisterKill(Kill, repSrcReg);
- }
- if (MRegisterInfo::isVirtualRegister(repDstReg)) {
- // If both are virtual registers...
- LiveVariables::VarInfo& dvi = lv_->getVarInfo(repDstReg);
- for (unsigned i = 0, e = dvi.Kills.size(); i != e; ++i) {
- MachineInstr *Kill = dvi.Kills[i];
- if (Kill == CopyMI || isRemoved(Kill))
- continue;
- if (DestInt.liveAt(getInstructionIndex(Kill) + InstrSlots::NUM))
- unsetRegisterKill(Kill, repDstReg);
- }
- }
+#if 1
+ // Remember these liveintervals have been joined.
+ JoinedLIs.set(repSrcReg - MRegisterInfo::FirstVirtualRegister);
+ if (MRegisterInfo::isVirtualRegister(repDstReg))
+ JoinedLIs.set(repDstReg - MRegisterInfo::FirstVirtualRegister);
// If the intervals were swapped by Join, swap them back so that the register
// mapping (in the r2i map) is correct.
@@ -1427,8 +1412,10 @@
void LiveIntervals::joinIntervals() {
DOUT << "********** JOINING INTERVALS ***********\n";
+ JoinedLIs.resize(getNumIntervals());
+ JoinedLIs.reset();
+
std::vector<CopyRec> TryAgainList;
-
const LoopInfo &LI = getAnalysis<LoopInfo>();
if (LI.begin() == LI.end()) {
// If there are no loops in the function, join intervals in function order.
@@ -1467,6 +1454,27 @@
}
}
}
+
+ // Some live range has been lengthened due to colaescing, eliminate the
+ // unnecessary kills.
+ int RegNum = JoinedLIs.find_first();
+ while (RegNum != -1) {
+ unsigned Reg = RegNum + MRegisterInfo::FirstVirtualRegister;
+ unsigned repReg = rep(Reg);
+ LiveInterval &LI = getInterval(repReg);
+ LiveVariables::VarInfo& svi = lv_->getVarInfo(Reg);
+ for (unsigned i = 0, e = svi.Kills.size(); i != e; ++i) {
+ MachineInstr *Kill = svi.Kills[i];
+ // Suppose vr1 = op vr2, x
+ // and vr1 and vr2 are coalesced. vr2 should still be marked kill
+ // unless it is a two-address operand.
+ if (isRemoved(Kill) || hasRegisterDef(Kill, repReg))
+ continue;
+ if (LI.liveAt(getInstructionIndex(Kill) + InstrSlots::NUM))
+ unsetRegisterKill(Kill, repReg);
+ }
+ RegNum = JoinedLIs.find_next(RegNum);
+ }
DOUT << "*** Register mapping ***\n";
for (int i = 0, e = r2rMap_.size(); i != e; ++i)
@@ -1541,6 +1549,18 @@
}
}
+/// hasRegisterDef - True if the instruction defines the specific register.
+///
+bool LiveIntervals::hasRegisterDef(MachineInstr *MI, unsigned Reg) {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDef() &&
+ mri_->regsOverlap(rep(MO.getReg()), Reg))
+ return true;
+ }
+ return false;
+}
+
LiveInterval LiveIntervals::createInterval(unsigned reg) {
float Weight = MRegisterInfo::isPhysicalRegister(reg) ?
HUGE_VALF : 0.0F;
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