Fix PR5614: parts of a physical register def may be killed the rest.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90180 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index bfc2d08..68f80ac 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -279,6 +279,43 @@
PhysRegUse[SubReg] = MI;
}
+/// FindLastRefOrPartRef - Return the last reference or partial reference of
+/// the specified register.
+MachineInstr *LiveVariables::FindLastRefOrPartRef(unsigned Reg) {
+ MachineInstr *LastDef = PhysRegDef[Reg];
+ MachineInstr *LastUse = PhysRegUse[Reg];
+ if (!LastDef && !LastUse)
+ return false;
+
+ MachineInstr *LastRefOrPartRef = LastUse ? LastUse : LastDef;
+ unsigned LastRefOrPartRefDist = DistanceMap[LastRefOrPartRef];
+ MachineInstr *LastPartDef = 0;
+ unsigned LastPartDefDist = 0;
+ for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
+ unsigned SubReg = *SubRegs; ++SubRegs) {
+ MachineInstr *Def = PhysRegDef[SubReg];
+ if (Def && Def != LastDef) {
+ // There was a def of this sub-register in between. This is a partial
+ // def, keep track of the last one.
+ unsigned Dist = DistanceMap[Def];
+ if (Dist > LastPartDefDist) {
+ LastPartDefDist = Dist;
+ LastPartDef = Def;
+ }
+ continue;
+ }
+ if (MachineInstr *Use = PhysRegUse[SubReg]) {
+ unsigned Dist = DistanceMap[Use];
+ if (Dist > LastRefOrPartRefDist) {
+ LastRefOrPartRefDist = Dist;
+ LastRefOrPartRef = Use;
+ }
+ }
+ }
+
+ return LastRefOrPartRef;
+}
+
bool LiveVariables::HandlePhysRegKill(unsigned Reg, MachineInstr *MI) {
MachineInstr *LastDef = PhysRegDef[Reg];
MachineInstr *LastUse = PhysRegUse[Reg];
@@ -373,7 +410,16 @@
if (NeedDef)
PhysRegDef[Reg]->addOperand(MachineOperand::CreateReg(SubReg,
true/*IsDef*/, true/*IsImp*/));
- LastRefOrPartRef->addRegisterKilled(SubReg, TRI, true);
+ MachineInstr *LastSubRef = FindLastRefOrPartRef(SubReg);
+ if (LastSubRef)
+ LastSubRef->addRegisterKilled(SubReg, TRI, true);
+ else {
+ LastRefOrPartRef->addRegisterKilled(SubReg, TRI, true);
+ PhysRegUse[SubReg] = LastRefOrPartRef;
+ for (const unsigned *SSRegs = TRI->getSubRegisters(SubReg);
+ unsigned SSReg = *SSRegs; ++SSRegs)
+ PhysRegUse[SSReg] = LastRefOrPartRef;
+ }
for (const unsigned *SS = TRI->getSubRegisters(SubReg); *SS; ++SS)
PartUses.erase(*SS);
}