Clear kill flags before propagating a copy.
The live range of the source register may be extended when a redundant
copy is eliminated. Make sure any kill flags between the two copies are
cleared.
This fixes PR11765.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149069 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineCopyPropagation.cpp b/lib/CodeGen/MachineCopyPropagation.cpp
index c82f81b..f96c869 100644
--- a/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/lib/CodeGen/MachineCopyPropagation.cpp
@@ -142,7 +142,12 @@
// %RSP<def> = COPY %RAX
// CALL
// %RAX<def> = COPY %RSP
- CopyMI->getOperand(1).setIsKill(false);
+
+ // Clear any kills of Def between CopyMI and MI. This extends the
+ // live range.
+ for (MachineBasicBlock::iterator I = CopyMI, E = MI; I != E; ++I)
+ I->clearRegisterKills(Def, TRI);
+
MI->eraseFromParent();
Changed = true;
++NumDeletes;
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 18e9f1a..c281cd1 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1707,6 +1707,20 @@
return Found;
}
+void MachineInstr::clearRegisterKills(unsigned Reg,
+ const TargetRegisterInfo *RegInfo) {
+ if (!TargetRegisterInfo::isPhysicalRegister(Reg))
+ RegInfo = 0;
+ for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = getOperand(i);
+ if (!MO.isReg() || !MO.isUse() || !MO.isKill())
+ continue;
+ unsigned OpReg = MO.getReg();
+ if (OpReg == Reg || (RegInfo && RegInfo->isSuperRegister(Reg, OpReg)))
+ MO.setIsKill(false);
+ }
+}
+
bool MachineInstr::addRegisterDead(unsigned IncomingReg,
const TargetRegisterInfo *RegInfo,
bool AddIfNotFound) {