#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
TII = tii;
TRI = tri;
MMI = mmi;
-
- RS = TRI->requiresRegisterScavenging(MF) ? new RegScavenger() : NULL;
+ RS = NULL;
+
+ // Use a RegScavenger to help update liveness when required.
+ MachineRegisterInfo &MRI = MF.getRegInfo();
+ if (MRI.tracksLiveness() && TRI->requiresRegisterScavenging(MF))
+ RS = new RegScavenger();
+ else
+ MRI.invalidateLiveness();
// Fix CFG. The later algorithms expect it to be right.
bool MadeChange = false;