//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/LivePhysRegs.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBundle.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
/// Simulates liveness when stepping forward over an instruction(bundle): Remove
/// killed-uses, add defs. This is the not recommended way, because it depends
-/// on accurate kill flags. If possible use stepBackwards() instead of this
+/// on accurate kill flags. If possible use stepBackward() instead of this
/// function.
void LivePhysRegs::stepForward(const MachineInstr &MI,
SmallVectorImpl<std::pair<unsigned, const MachineOperand*>> &Clobbers) {
if (Reg == 0)
continue;
if (O->isDef()) {
- if (!O->isDead())
- Clobbers.push_back(std::make_pair(Reg, &*O));
+ // Note, dead defs are still recorded. The caller should decide how to
+ // handle them.
+ Clobbers.push_back(std::make_pair(Reg, &*O));
} else {
if (!O->isKill())
continue;
}
// Add defs to the set.
- for (auto Reg : Clobbers)
+ for (auto Reg : Clobbers) {
+ // Skip dead defs. They shouldn't be added to the set.
+ if (Reg.second->isReg() && Reg.second->isDead())
+ continue;
addReg(Reg.first);
+ }
}
/// Prin the currently live registers to OS.
dbgs() << " " << *this;
#endif
}
+
+/// Add live-in registers of basic block \p MBB to \p LiveRegs.
+static void addLiveIns(LivePhysRegs &LiveRegs, const MachineBasicBlock &MBB) {
+ for (const auto &LI : MBB.liveins())
+ LiveRegs.addReg(LI.PhysReg);
+}
+
+/// 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 TargetRegisterInfo &TRI) {
+ const MachineFrameInfo &MFI = *MF.getFrameInfo();
+ if (!MFI.isCalleeSavedInfoValid())
+ return;
+
+ for (const MCPhysReg *CSR = TRI.getCalleeSavedRegs(&MF); CSR && *CSR; ++CSR)
+ LiveRegs.addReg(*CSR);
+ for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
+ LiveRegs.removeReg(Info.getReg());
+}
+
+void LivePhysRegs::addLiveOuts(const MachineBasicBlock *MBB,
+ bool AddPristinesAndCSRs) {
+ if (AddPristinesAndCSRs) {
+ const MachineFunction &MF = *MBB->getParent();
+ addPristines(*this, MF, *TRI);
+ 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.
+ for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
+ addReg(*I);
+ }
+ }
+
+ // To get the live-outs we simply merge the live-ins of all successors.
+ for (const MachineBasicBlock *Succ : MBB->successors())
+ ::addLiveIns(*this, *Succ);
+}
+
+void LivePhysRegs::addLiveIns(const MachineBasicBlock *MBB,
+ bool AddPristines) {
+ if (AddPristines) {
+ const MachineFunction &MF = *MBB->getParent();
+ addPristines(*this, MF, *TRI);
+ }
+ ::addLiveIns(*this, *MBB);
+}