+++ /dev/null
-//===- llvm/CodeGen/LivePhysRegs.h - Live Physical Register Set -*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a set of live physical registers. This can be used for
-// ad hoc liveness tracking after register allocation. You can start with the
-// live-ins/live-outs at the beginning/end of a block and update the information
-// while walking the instructions inside the block.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_CODEGEN_LIVE_PHYS_REGS_H
-#define LLVM_CODEGEN_LIVE_PHYS_REGS_H
-
-#include "llvm/ADT/SparseSet.h"
-#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/Target/TargetRegisterInfo.h"
-#include <cassert>
-
-namespace llvm {
-
-class MachineInstr;
-
-/// \brief A set of live physical registers with functions to track liveness
-/// when walking backward/forward through a basic block.
-class LivePhysRegs {
- const TargetRegisterInfo *TRI;
- SparseSet<unsigned> LiveRegs;
-
- LivePhysRegs(const LivePhysRegs&) LLVM_DELETED_FUNCTION;
- LivePhysRegs &operator=(const LivePhysRegs&) LLVM_DELETED_FUNCTION;
-public:
- /// \brief Constructs a new empty LivePhysRegs set.
- LivePhysRegs() : TRI(0), LiveRegs() {}
-
- /// \brief Constructs and initialize an empty LivePhysRegs set.
- LivePhysRegs(const TargetRegisterInfo *TRI) : TRI(TRI) {
- LiveRegs.setUniverse(TRI->getNumRegs());
- }
-
- /// \brief Clear and initialize the LivePhysRegs set.
- void init(const TargetRegisterInfo *_TRI) {
- TRI = _TRI;
- LiveRegs.clear();
- LiveRegs.setUniverse(TRI->getNumRegs());
- }
-
- /// \brief Clears the LivePhysRegs set.
- void clear() { LiveRegs.clear(); }
-
- /// \brief Returns true if the set is empty.
- bool empty() const { return LiveRegs.empty(); }
-
- /// \brief Adds a physical register and all its sub-registers to the set.
- void addReg(unsigned Reg) {
- assert(TRI && "LivePhysRegs is not initialized.");
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.insert(*SubRegs);
- }
-
- /// \brief Removes a physical register, all its sub-registers, and all its
- /// super-registers from the set.
- void removeReg(unsigned Reg) {
- assert(TRI && "LivePhysRegs is not initialized.");
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.erase(*SubRegs);
- for (MCSuperRegIterator SuperRegs(Reg, TRI, /*IncludeSelf=*/false);
- SuperRegs.isValid(); ++SuperRegs)
- LiveRegs.erase(*SuperRegs);
- }
-
- /// \brief Removes physical registers clobbered by the regmask operand @p MO.
- void removeRegsInMask(const MachineOperand &MO);
-
- /// \brief Returns true if register @p Reg is contained in the set. This also
- /// works if only the super register of @p Reg has been defined, because we
- /// always add also all sub-registers to the set.
- bool contains(unsigned Reg) const { return LiveRegs.count(Reg); }
-
- /// \brief Simulates liveness when stepping backwards over an
- /// instruction(bundle): Remove Defs, add uses. This is the recommended way of
- /// calculating liveness.
- void stepBackward(const MachineInstr &MI);
-
- /// \brief 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 function.
- void stepForward(const MachineInstr &MI);
-
- /// \brief Adds all live-in registers of basic block @p MBB.
- void addLiveIns(const MachineBasicBlock *MBB) {
- for (MachineBasicBlock::livein_iterator LI = MBB->livein_begin(),
- LE = MBB->livein_end(); LI != LE; ++LI)
- addReg(*LI);
- }
-
- /// \brief Adds all live-out registers of basic block @p MBB.
- void addLiveOuts(const MachineBasicBlock *MBB) {
- for (MachineBasicBlock::const_succ_iterator SI = MBB->succ_begin(),
- SE = MBB->succ_end(); SI != SE; ++SI)
- addLiveIns(*SI);
- }
-
- typedef SparseSet<unsigned>::const_iterator const_iterator;
- const_iterator begin() const { return LiveRegs.begin(); }
- const_iterator end() const { return LiveRegs.end(); }
-};
-
-} // namespace llvm
-
-#endif