1 //===--- LiveRangeEdit.cpp - Basic tools for editing a register live range --===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // The LiveRangeEdit class represents changes done to a virtual register when it
11 // is spilled or split.
12 //===----------------------------------------------------------------------===//
14 #include "LiveRangeEdit.h"
15 #include "VirtRegMap.h"
16 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
17 #include "llvm/CodeGen/MachineRegisterInfo.h"
21 int LiveRangeEdit::assignStackSlot(VirtRegMap &vrm) {
22 int ss = vrm.getStackSlot(getReg());
23 if (ss != VirtRegMap::NO_STACK_SLOT)
25 return vrm.assignVirt2StackSlot(getReg());
28 LiveInterval &LiveRangeEdit::create(MachineRegisterInfo &mri,
31 const TargetRegisterClass *RC = mri.getRegClass(parent_.reg);
32 unsigned VReg = mri.createVirtualRegister(RC);
34 // Immediately assign to the same stack slot as parent.
35 vrm.assignVirt2StackSlot(VReg, assignStackSlot(vrm));
36 LiveInterval &li = lis.getOrCreateInterval(VReg);
37 newRegs_.push_back(&li);
41 /// allUsesAvailableAt - Return true if all registers used by OrigMI at
42 /// OrigIdx are also available with the same value at UseIdx.
43 bool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI,
47 OrigIdx = OrigIdx.getUseIndex();
48 UseIdx = UseIdx.getUseIndex();
49 for (unsigned i = 0, e = OrigMI->getNumOperands(); i != e; ++i) {
50 const MachineOperand &MO = OrigMI->getOperand(i);
51 if (!MO.isReg() || !MO.getReg() || MO.getReg() == getReg())
53 // Reserved registers are OK.
54 if (MO.isUndef() || !lis.hasInterval(MO.getReg()))
56 // We don't want to move any defs.
59 // We cannot depend on virtual registers in uselessRegs_.
60 for (unsigned ui = 0, ue = uselessRegs_.size(); ui != ue; ++ui)
61 if (uselessRegs_[ui]->reg == MO.getReg())
64 LiveInterval &li = lis.getInterval(MO.getReg());
65 const VNInfo *OVNI = li.getVNInfoAt(OrigIdx);
68 if (OVNI != li.getVNInfoAt(UseIdx))