//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the Evan Cheng and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/DenseMap.h"
namespace llvm {
-class MRegisterInfo;
+class MachineRegisterInfo;
+class TargetRegisterInfo;
class TargetInstrInfo;
class TargetRegisterClass;
class RegScavenger {
+ const TargetRegisterInfo *TRI;
+ const TargetInstrInfo *TII;
+ MachineRegisterInfo* MRI;
MachineBasicBlock *MBB;
MachineBasicBlock::iterator MBBI;
unsigned NumPhysRegs;
///
const TargetRegisterClass *ScavengedRC;
- /// RegStates - The current state of all the physical registers immediately
+ /// ScavengeRestore - Instruction that restores the scavenged register from
+ /// stack.
+ const MachineInstr *ScavengeRestore;
+
+ /// CalleeSavedrRegs - A bitvector of callee saved registers for the target.
+ ///
+ BitVector CalleeSavedRegs;
+
+ /// ReservedRegs - A bitvector of reserved registers.
+ ///
+ BitVector ReservedRegs;
+
+ /// RegsAvailable - The current state of all the physical registers immediately
/// before MBBI. One bit per physical register. If bit is set that means it's
/// available, unset means the register is currently being used.
- BitVector RegStates;
+ BitVector RegsAvailable;
+
+ /// CurrDist - Distance from MBB entry to the current instruction MBBI.
+ ///
+ unsigned CurrDist;
+
+ /// DistanceMap - Keep track the distance of a MI from the start of the
+ /// current basic block.
+ DenseMap<MachineInstr*, unsigned> DistanceMap;
public:
RegScavenger()
: MBB(NULL), NumPhysRegs(0), Tracking(false),
- ScavengingFrameIndex(-1), ScavengedReg(0), ScavengedRC(NULL) {};
-
- RegScavenger(MachineBasicBlock *mbb)
- : MBB(mbb), NumPhysRegs(0), Tracking(false),
- ScavengingFrameIndex(-1), ScavengedReg(0), ScavengedRC(NULL) {};
+ ScavengingFrameIndex(-1), ScavengedReg(0), ScavengedRC(NULL) {}
/// enterBasicBlock - Start tracking liveness from the begin of the specific
/// basic block.
void backward();
/// forward / backward - Move the internal MBB iterator and update register
- /// states until it has reached but not processed the specific iterator.
+ /// states until it has processed the specific iterator.
void forward(MachineBasicBlock::iterator I) {
+ if (!Tracking && MBB->begin() != I) forward();
while (MBBI != I) forward();
}
void backward(MachineBasicBlock::iterator I) {
/// isUsed / isUsed - Test if a register is currently being used.
///
- bool isUsed(unsigned Reg) const { return !RegStates[Reg]; }
- bool isUnused(unsigned Reg) const { return RegStates[Reg]; }
+ bool isUsed(unsigned Reg) const { return !RegsAvailable[Reg]; }
+ bool isUnused(unsigned Reg) const { return RegsAvailable[Reg]; }
+
+ /// getRegsUsed - return all registers currently in use in used.
+ void getRegsUsed(BitVector &used, bool includeReserved);
/// setUsed / setUnused - Mark the state of one or a number of registers.
///
- void setUsed(unsigned Reg) { RegStates.reset(Reg); }
- void setUsed(BitVector Regs) { RegStates &= ~Regs; }
- void setUnused(unsigned Reg) { RegStates.set(Reg); }
- void setUnused(BitVector Regs) { RegStates |= Regs; }
+ void setUsed(unsigned Reg);
+ void setUsed(BitVector &Regs) {
+ RegsAvailable &= ~Regs;
+ }
+ void setUnused(unsigned Reg, const MachineInstr *MI);
+ void setUnused(BitVector &Regs) {
+ RegsAvailable |= Regs;
+ }
/// FindUnusedReg - Find a unused register of the specified register class
/// from the specified set of registers. It return 0 is none is found.
int getScavengingFrameIndex() const { return ScavengingFrameIndex; }
/// scavengeRegister - Make a register of the specific register class
- /// available and do the appropriate bookkeeping. Returns the scavenged
- /// register.
+ /// available and do the appropriate bookkeeping. SPAdj is the stack
+ /// adjustment due to call frame, it's passed along to eliminateFrameIndex().
+ /// Returns the scavenged register.
unsigned scavengeRegister(const TargetRegisterClass *RegClass,
- MachineBasicBlock::iterator I);
- unsigned scavengeRegister(const TargetRegisterClass *RegClass) {
- return scavengeRegister(RegClass, MBBI);
+ MachineBasicBlock::iterator I, int SPAdj);
+ unsigned scavengeRegister(const TargetRegisterClass *RegClass, int SPAdj) {
+ return scavengeRegister(RegClass, MBBI, SPAdj);
}
private:
- const MRegisterInfo *RegInfo;
- const TargetInstrInfo *TII;
-
- /// CalleeSavedrRegs - A bitvector of callee saved registers for the target.
- ///
- BitVector CalleeSavedRegs;
-
- /// ReservedRegs - A bitvector of reserved registers.
- ///
- BitVector ReservedRegs;
-
/// restoreScavengedReg - Restore scavenged by loading it back from the
/// emergency spill slot. Mark it used.
void restoreScavengedReg();
+
+ MachineInstr *findFirstUse(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator I, unsigned Reg,
+ unsigned &Dist);
};
} // End llvm namespace