forked from OSchip/llvm-project
131 lines
5.1 KiB
C++
131 lines
5.1 KiB
C++
//===---- LiveRangeEdit.h - Basic tools for split and spill -----*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// The LiveRangeEdit class represents changes done to a virtual register when it
|
|
// is spilled or split.
|
|
//
|
|
// The parent register is never changed. Instead, a number of new virtual
|
|
// registers are created and added to the newRegs vector.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_CODEGEN_LIVERANGEEDIT_H
|
|
#define LLVM_CODEGEN_LIVERANGEEDIT_H
|
|
|
|
#include "llvm/CodeGen/LiveInterval.h"
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
|
|
namespace llvm {
|
|
|
|
class AliasAnalysis;
|
|
class LiveIntervals;
|
|
class MachineRegisterInfo;
|
|
class VirtRegMap;
|
|
|
|
class LiveRangeEdit {
|
|
LiveInterval &parent_;
|
|
SmallVectorImpl<LiveInterval*> &newRegs_;
|
|
const SmallVectorImpl<LiveInterval*> &uselessRegs_;
|
|
|
|
/// firstNew_ - Index of the first register added to newRegs_.
|
|
const unsigned firstNew_;
|
|
|
|
/// scannedRemattable_ - true when remattable values have been identified.
|
|
bool scannedRemattable_;
|
|
|
|
/// remattable_ - Values defined by remattable instructions as identified by
|
|
/// tii.isTriviallyReMaterializable().
|
|
SmallPtrSet<VNInfo*,4> remattable_;
|
|
|
|
/// rematted_ - Values that were actually rematted, and so need to have their
|
|
/// live range trimmed or entirely removed.
|
|
SmallPtrSet<VNInfo*,4> rematted_;
|
|
|
|
/// scanRemattable - Identify the parent_ values that may rematerialize.
|
|
void scanRemattable(LiveIntervals &lis,
|
|
const TargetInstrInfo &tii,
|
|
AliasAnalysis *aa);
|
|
|
|
/// allUsesAvailableAt - Return true if all registers used by OrigMI at
|
|
/// OrigIdx are also available with the same value at UseIdx.
|
|
bool allUsesAvailableAt(const MachineInstr *OrigMI, SlotIndex OrigIdx,
|
|
SlotIndex UseIdx, LiveIntervals &lis);
|
|
|
|
public:
|
|
/// Create a LiveRangeEdit for breaking down parent into smaller pieces.
|
|
/// @param parent The register being spilled or split.
|
|
/// @param newRegs List to receive any new registers created. This needn't be
|
|
/// empty initially, any existing registers are ignored.
|
|
/// @param uselessRegs List of registers that can't be used when
|
|
/// rematerializing values because they are about to be removed.
|
|
LiveRangeEdit(LiveInterval &parent,
|
|
SmallVectorImpl<LiveInterval*> &newRegs,
|
|
const SmallVectorImpl<LiveInterval*> &uselessRegs)
|
|
: parent_(parent), newRegs_(newRegs), uselessRegs_(uselessRegs),
|
|
firstNew_(newRegs.size()), scannedRemattable_(false) {}
|
|
|
|
LiveInterval &getParent() const { return parent_; }
|
|
unsigned getReg() const { return parent_.reg; }
|
|
|
|
/// Iterator for accessing the new registers added by this edit.
|
|
typedef SmallVectorImpl<LiveInterval*>::const_iterator iterator;
|
|
iterator begin() const { return newRegs_.begin()+firstNew_; }
|
|
iterator end() const { return newRegs_.end(); }
|
|
|
|
/// assignStackSlot - Ensure a stack slot is assigned to parent.
|
|
/// @return the assigned stack slot number.
|
|
int assignStackSlot(VirtRegMap&);
|
|
|
|
/// create - Create a new register with the same class and stack slot as
|
|
/// parent.
|
|
LiveInterval &create(MachineRegisterInfo&, LiveIntervals&, VirtRegMap&);
|
|
|
|
/// anyRematerializable - Return true if any parent values may be
|
|
/// rematerializable.
|
|
/// This function must be called before ny rematerialization is attempted.
|
|
bool anyRematerializable(LiveIntervals&, const TargetInstrInfo&,
|
|
AliasAnalysis*);
|
|
|
|
/// Remat - Information needed to rematerialize at a specific location.
|
|
struct Remat {
|
|
VNInfo *ParentVNI; // parent_'s value at the remat location.
|
|
MachineInstr *OrigMI; // Instruction defining ParentVNI.
|
|
operator bool() const { return OrigMI; }
|
|
};
|
|
|
|
/// canRematerializeAt - Determine if ParentVNI can be rematerialized at
|
|
/// UseIdx. It is assumed that parent_.getVNINfoAt(UseIdx) == ParentVNI.
|
|
/// When cheapAsAMove is set, only cheap remats are allowed.
|
|
Remat canRematerializeAt(VNInfo *ParentVNI,
|
|
SlotIndex UseIdx,
|
|
bool cheapAsAMove,
|
|
LiveIntervals &lis);
|
|
|
|
/// rematerializeAt - Rematerialize RM.ParentVNI into DestReg by inserting an
|
|
/// instruction into MBB before MI. The new instruction is mapped, but
|
|
/// liveness is not updated.
|
|
/// Return the SlotIndex of the new instruction.
|
|
SlotIndex rematerializeAt(MachineBasicBlock &MBB,
|
|
MachineBasicBlock::iterator MI,
|
|
unsigned DestReg,
|
|
const Remat &RM,
|
|
LiveIntervals&,
|
|
const TargetInstrInfo&,
|
|
const TargetRegisterInfo&);
|
|
|
|
/// didRematerialize - Return true if ParentVNI was rematerialized anywhere.
|
|
bool didRematerialize(VNInfo *ParentVNI) const {
|
|
return rematted_.count(ParentVNI);
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|