- Treat a live range defined by an implicit_def as a zero-sized one.
- Eliminate an implicit_def when it's being spilled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49166 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index bab6a29..91528e2 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -201,6 +201,11 @@
DOUT << "\t\tregister: "; DEBUG(printRegName(interval.reg));
LiveVariables::VarInfo& vi = lv_->getVarInfo(interval.reg);
+ if (mi->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
+ DOUT << "is a implicit_def\n";
+ return;
+ }
+
// Virtual registers may be defined multiple times (due to phi
// elimination and 2-addr elimination). Much of what we do only has to be
// done once for the vreg. We use an empty interval to detect the first
@@ -1105,7 +1110,7 @@
std::vector<RewriteInfo> RewriteMIs;
for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(li.reg),
re = mri_->reg_end(); ri != re; ) {
- MachineInstr *MI = &(*ri);
+ MachineInstr *MI = &*ri;
MachineOperand &O = ri.getOperand();
++ri;
assert(!O.isImplicit() && "Spilling register that's used as implicit use?");
@@ -1307,6 +1312,22 @@
Restores[i].index = -1;
}
+/// removeSpilledImpDefs - Remove IMPLICIT_DEF instructions which are being
+/// spilled.
+void LiveIntervals::removeSpilledImpDefs(const LiveInterval &li,
+ VirtRegMap &vrm) {
+ for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(li.reg),
+ re = mri_->reg_end(); ri != re; ) {
+ MachineInstr *MI = &*ri;
+ ++ri;
+ if (MI->getOpcode() != TargetInstrInfo::IMPLICIT_DEF)
+ continue;
+ RemoveMachineInstrFromMaps(MI);
+ vrm.RemoveMachineInstrFromMaps(MI);
+ MI->eraseFromParent();
+ }
+}
+
std::vector<LiveInterval*> LiveIntervals::
addIntervalsForSpills(const LiveInterval &li,
@@ -1386,6 +1407,8 @@
}
IsFirstRange = false;
}
+
+ removeSpilledImpDefs(li, vrm);
return NewLIs;
}
@@ -1454,8 +1477,10 @@
}
// Insert spills / restores if we are splitting.
- if (!TrySplit)
+ if (!TrySplit) {
+ removeSpilledImpDefs(li, vrm);
return NewLIs;
+ }
SmallPtrSet<LiveInterval*, 4> AddedKill;
SmallVector<unsigned, 2> Ops;
@@ -1608,6 +1633,7 @@
}
}
+ removeSpilledImpDefs(li, vrm);
return RetNewLIs;
}