}
}
-/// Add pristine registers to the given \p LiveRegs. This function removes
-/// actually saved callee save registers when \p InPrologueEpilogue is false.
-static void addPristines(LivePhysRegs &LiveRegs, const MachineFunction &MF,
- const MachineFrameInfo &MFI,
- const TargetRegisterInfo &TRI) {
+/// Adds all callee saved registers to \p LiveRegs.
+static void addCalleeSavedRegs(LivePhysRegs &LiveRegs,
+ const MachineFunction &MF) {
const MachineRegisterInfo &MRI = MF.getRegInfo();
- for (const MCPhysReg *CSR = MRI.getCalleeSavedRegs(); CSR && *CSR;
- ++CSR)
+ for (const MCPhysReg *CSR = MRI.getCalleeSavedRegs(); CSR && *CSR; ++CSR)
LiveRegs.addReg(*CSR);
+}
+
+/// Adds pristine registers to the given \p LiveRegs. Pristine registers are
+/// callee saved registers that are unused in the function.
+static void addPristines(LivePhysRegs &LiveRegs, const MachineFunction &MF) {
+ const MachineFrameInfo &MFI = MF.getFrameInfo();
+ if (!MFI.isCalleeSavedInfoValid())
+ return;
+ /// Add all callee saved regs, then remove the ones that are saved+restored.
+ addCalleeSavedRegs(LiveRegs, MF);
+ /// Remove the ones that are not saved/restored; they are pristine.
for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
LiveRegs.removeReg(Info.getReg());
}
void LivePhysRegs::addLiveOutsNoPristines(const MachineBasicBlock &MBB) {
- // To get the live-outs we simply merge the live-ins of all successors.
- for (const MachineBasicBlock *Succ : MBB.successors())
- addBlockLiveIns(*Succ);
+ if (!MBB.succ_empty()) {
+ // To get the live-outs we simply merge the live-ins of all successors.
+ for (const MachineBasicBlock *Succ : MBB.successors())
+ addBlockLiveIns(*Succ);
+ } else if (MBB.isReturnBlock()) {
+ // For the return block: Add all callee saved registers that are saved and
+ // restored (somewhere); This does not include callee saved registers that
+ // are unused and hence not saved and restored; they are called pristine.
+ const MachineFunction &MF = *MBB.getParent();
+ const MachineFrameInfo &MFI = MF.getFrameInfo();
+ if (MFI.isCalleeSavedInfoValid()) {
+ for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
+ addReg(Info.getReg());
+ }
+ }
}
void LivePhysRegs::addLiveOuts(const MachineBasicBlock &MBB) {
- const MachineFunction &MF = *MBB.getParent();
- const MachineFrameInfo &MFI = MF.getFrameInfo();
- if (MFI.isCalleeSavedInfoValid()) {
- if (MBB.isReturnBlock()) {
- // The return block has no successors whose live-ins we could merge
- // below. So instead we add the callee saved registers manually.
- const MachineRegisterInfo &MRI = MF.getRegInfo();
- for (const MCPhysReg *I = MRI.getCalleeSavedRegs(); *I; ++I)
- addReg(*I);
- } else {
- addPristines(*this, MF, MFI, *TRI);
- }
+ if (!MBB.succ_empty()) {
+ addLiveOutsNoPristines(MBB);
+ const MachineFunction &MF = *MBB.getParent();
+ addPristines(*this, MF);
+ } else if (MBB.isReturnBlock()) {
+ // For the return block: Add all callee saved registers.
+ const MachineFunction &MF = *MBB.getParent();
+ const MachineFrameInfo &MFI = MF.getFrameInfo();
+ if (MFI.isCalleeSavedInfoValid())
+ addCalleeSavedRegs(*this, MF);
}
-
- addLiveOutsNoPristines(MBB);
}
void LivePhysRegs::addLiveIns(const MachineBasicBlock &MBB) {
const MachineFunction &MF = *MBB.getParent();
- const MachineFrameInfo &MFI = MF.getFrameInfo();
- if (MFI.isCalleeSavedInfoValid())
- addPristines(*this, MF, MFI, *TRI);
+ addPristines(*this, MF);
addBlockLiveIns(MBB);
}