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Diffstat (limited to 'lib/CodeGen/LiveRangeEdit.cpp')
-rw-r--r-- | lib/CodeGen/LiveRangeEdit.cpp | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp new file mode 100644 index 0000000..8a123fb --- /dev/null +++ b/lib/CodeGen/LiveRangeEdit.cpp @@ -0,0 +1,64 @@ +//===--- LiveRangeEdit.cpp - Basic tools for editing a register live range --===// +// +// 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. +//===----------------------------------------------------------------------===// + +#include "LiveRangeEdit.h" +#include "VirtRegMap.h" +#include "llvm/CodeGen/LiveIntervalAnalysis.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" + +using namespace llvm; + +LiveInterval &LiveRangeEdit::create(MachineRegisterInfo &mri, + LiveIntervals &lis, + VirtRegMap &vrm) { + const TargetRegisterClass *RC = mri.getRegClass(parent_.reg); + unsigned VReg = mri.createVirtualRegister(RC); + vrm.grow(); + LiveInterval &li = lis.getOrCreateInterval(VReg); + newRegs_.push_back(&li); + return li; +} + +/// allUsesAvailableAt - Return true if all registers used by OrigMI at +/// OrigIdx are also available with the same value at UseIdx. +bool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI, + SlotIndex OrigIdx, + SlotIndex UseIdx, + LiveIntervals &lis) { + OrigIdx = OrigIdx.getUseIndex(); + UseIdx = UseIdx.getUseIndex(); + for (unsigned i = 0, e = OrigMI->getNumOperands(); i != e; ++i) { + const MachineOperand &MO = OrigMI->getOperand(i); + if (!MO.isReg() || !MO.getReg() || MO.getReg() == getReg()) + continue; + // Reserved registers are OK. + if (MO.isUndef() || !lis.hasInterval(MO.getReg())) + continue; + // We don't want to move any defs. + if (MO.isDef()) + return false; + // We cannot depend on virtual registers in uselessRegs_. + for (unsigned ui = 0, ue = uselessRegs_.size(); ui != ue; ++ui) + if (uselessRegs_[ui]->reg == MO.getReg()) + return false; + + LiveInterval &li = lis.getInterval(MO.getReg()); + const VNInfo *OVNI = li.getVNInfoAt(OrigIdx); + if (!OVNI) + continue; + if (OVNI != li.getVNInfoAt(UseIdx)) + return false; + } + return true; +} + |