Be careful when to add implicit kill / dead operands. Don't add them during / post reg-allocation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36458 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index a2b1703..fcefe26 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -170,7 +170,8 @@
MarkVirtRegAliveInBlock(VRInfo, *PI);
}
-void LiveVariables::addRegisterKilled(unsigned IncomingReg, MachineInstr *MI) {
+bool LiveVariables::addRegisterKilled(unsigned IncomingReg, MachineInstr *MI,
+ bool AddIfNotFound) {
bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
@@ -187,17 +188,21 @@
RegInfo->isSuperRegister(IncomingReg, Reg) &&
MO.isKill())
// A super-register kill already exists.
- return;
+ return true;
}
}
// If not found, this means an alias of one of the operand is killed. Add a
- // new implicit operand.
- if (!Found)
+ // new implicit operand if required.
+ if (!Found && AddIfNotFound) {
MI->addRegOperand(IncomingReg, false/*IsDef*/,true/*IsImp*/,true/*IsKill*/);
+ return true;
+ }
+ return Found;
}
-void LiveVariables::addRegisterDead(unsigned IncomingReg, MachineInstr *MI) {
+bool LiveVariables::addRegisterDead(unsigned IncomingReg, MachineInstr *MI,
+ bool AddIfNotFound) {
bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
@@ -214,15 +219,18 @@
RegInfo->isSuperRegister(IncomingReg, Reg) &&
MO.isDead())
// There exists a super-register that's marked dead.
- return;
+ return true;
}
}
// If not found, this means an alias of one of the operand is dead. Add a
// new implicit operand.
- if (!Found)
+ if (!Found && AddIfNotFound) {
MI->addRegOperand(IncomingReg, true/*IsDef*/,true/*IsImp*/,false/*IsKill*/,
true/*IsDead*/);
+ return true;
+ }
+ return Found;
}
void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) {
@@ -271,9 +279,9 @@
addRegisterKilled(Reg, LastRef);
else if (PhysRegPartUse[Reg])
// Add implicit use / kill to last use of a sub-register.
- addRegisterKilled(Reg, PhysRegPartUse[Reg]);
+ addRegisterKilled(Reg, PhysRegPartUse[Reg], true);
else
- addRegisterDead(Reg, LastRef);
+ addRegisterDead(Reg, LastRef, true);
}
PhysRegInfo[Reg] = MI;
PhysRegUsed[Reg] = false;