Revert "Convert liveness tracking to work on a sub-register level instead of just register units."

This reverts commit r197253.

This was a great change, but Juergen should be the commit author.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197262 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 88 insertions, 119 deletions

diff --git a/include/llvm/CodeGen/LivePhysRegs.h b/include/llvm/CodeGen/LivePhysRegs.h
deleted file mode 100644
index 5cb2421ffb..0000000000
--- a/include/llvm/CodeGen/LivePhysRegs.h
+++ /dev/null
@@ -1,119 +0,0 @@
-//===- 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
diff --git a/include/llvm/CodeGen/LiveRegUnits.h b/include/llvm/CodeGen/LiveRegUnits.h
new file mode 100644
index 0000000000..02b9c55cc6
--- /dev/null
+++ b/include/llvm/CodeGen/LiveRegUnits.h
@@ -0,0 +1,88 @@
+//===-- llvm/CodeGen/LiveRegUnits.h - Live register unit 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 register units. 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_LIVEREGUNITS_H
+#define LLVM_CODEGEN_LIVEREGUNITS_H
+
+#include "llvm/ADT/SparseSet.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include <cassert>
+
+namespace llvm {
+
+class MachineInstr;
+
+/// A set of live register units with functions to track liveness when walking
+/// backward/forward through a basic block.
+class LiveRegUnits {
+  SparseSet<unsigned> LiveUnits;
+
+  LiveRegUnits(const LiveRegUnits&) LLVM_DELETED_FUNCTION;
+  LiveRegUnits &operator=(const LiveRegUnits&) LLVM_DELETED_FUNCTION;
+public:
+  /// \brief Constructs a new empty LiveRegUnits set.
+  LiveRegUnits() {}
+
+  void init(const TargetRegisterInfo *TRI) {
+    LiveUnits.clear();
+    LiveUnits.setUniverse(TRI->getNumRegs());
+  }
+
+  void clear() { LiveUnits.clear(); }
+
+  bool empty() const { return LiveUnits.empty(); }
+
+  /// \brief Adds a register to the set.
+  void addReg(unsigned Reg, const MCRegisterInfo &MCRI) {
+    for (MCRegUnitIterator RUnits(Reg, &MCRI); RUnits.isValid(); ++RUnits)
+      LiveUnits.insert(*RUnits);
+  }
+
+  /// \brief Removes a register from the set.
+  void removeReg(unsigned Reg, const MCRegisterInfo &MCRI) {
+    for (MCRegUnitIterator RUnits(Reg, &MCRI); RUnits.isValid(); ++RUnits)
+      LiveUnits.erase(*RUnits);
+  }
+
+  /// \brief Removes registers clobbered by the regmask operand @p Op.
+  void removeRegsInMask(const MachineOperand &Op, const MCRegisterInfo &MCRI);
+
+  /// \brief Returns true if register @p Reg (or one of its super register) is
+  /// contained in the set.
+  bool contains(unsigned Reg, const MCRegisterInfo &MCRI) const {
+    for (MCRegUnitIterator RUnits(Reg, &MCRI); RUnits.isValid(); ++RUnits) {
+      if (LiveUnits.count(*RUnits))
+        return true;
+    }
+    return false;
+  }
+
+  /// \brief Simulates liveness when stepping backwards over an
+  /// instruction(bundle): Remove Defs, add uses.
+  void stepBackward(const MachineInstr &MI, const MCRegisterInfo &MCRI);
+
+  /// \brief Simulates liveness when stepping forward over an
+  /// instruction(bundle): Remove killed-uses, add defs.
+  void stepForward(const MachineInstr &MI, const MCRegisterInfo &MCRI);
+
+  /// \brief Adds all registers in the live-in list of block @p BB.
+  void addLiveIns(const MachineBasicBlock *MBB, const MCRegisterInfo &MCRI);
+};
+
+} // namespace llvm
+
+#endif