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LivePhysRegs: Fix addLiveOutsNoPristines() for return blocks past PEI 

- addLiveOutsNoPristines() needs to add callee saved registers that are
  actually saved and restored somewhere to the set (they are not
  pristine).
- Cleanup/rewrite the code for addLiveOuts()/addLiveOutsNoPristines().

This fixes the problem from D32156.

Differential Revision: https://reviews.llvm.org/D32464

llvm-svn: 303938
This commit is contained in:
Matthias Braun 2017-05-25 23:39:40 +00:00
parent 9512dd5ffd
commit e2133d5b42
1 changed files with 41 additions and 27 deletions
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68
llvm/lib/CodeGen/LivePhysRegs.cpp
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@ -155,48 +155,62 @@ void LivePhysRegs::addBlockLiveIns(const MachineBasicBlock &MBB) {
}
}
/// 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);
}