17842a741eb0e1baa35af8c3bb5884655c1edaa9eJim Grosbach//===-- LiveRangeEdit.cpp - Basic tools for editing a register live range -===// 2a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// 3a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// The LLVM Compiler Infrastructure 4a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// 5a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// This file is distributed under the University of Illinois Open Source 6a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// License. See LICENSE.TXT for details. 7a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// 8a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen//===----------------------------------------------------------------------===// 9a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// 10a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// The LiveRangeEdit class represents changes done to a virtual register when it 11a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen// is spilled or split. 12a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen//===----------------------------------------------------------------------===// 13a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen 14cf610d07de3ba4929bb5d00e084877dd974b44a1Jakob Stoklund Olesen#define DEBUG_TYPE "regalloc" 15a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen#include "VirtRegMap.h" 165881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen#include "llvm/ADT/SetVector.h" 17e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund Olesen#include "llvm/ADT/Statistic.h" 186094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen#include "llvm/CodeGen/CalcSpillWeights.h" 19a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen#include "llvm/CodeGen/LiveIntervalAnalysis.h" 20789d5d85ba6e9259a8e0f0bcfbd06a59ad164512Pete Cooper#include "llvm/CodeGen/LiveRangeEdit.h" 21a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen#include "llvm/CodeGen/MachineRegisterInfo.h" 22080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen#include "llvm/Target/TargetInstrInfo.h" 235881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen#include "llvm/Support/Debug.h" 245881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen#include "llvm/Support/raw_ostream.h" 25a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen 26a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesenusing namespace llvm; 27a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen 28e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund OlesenSTATISTIC(NumDCEDeleted, "Number of instructions deleted by DCE"); 29e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund OlesenSTATISTIC(NumDCEFoldedLoads, "Number of single use loads folded after DCE"); 30e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund OlesenSTATISTIC(NumFracRanges, "Number of live ranges fractured by DCE"); 31e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund Olesen 322d24e2a396a1d211baaeedf32148a3b657240170David Blaikievoid LiveRangeEdit::Delegate::anchor() { } 332d24e2a396a1d211baaeedf32148a3b657240170David Blaikie 348a06af96698537377275dd7848db69915638dd26Pete CooperLiveInterval &LiveRangeEdit::createFrom(unsigned OldReg) { 356a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen unsigned VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg)); 362e267ae7b8caf7192a3793eb3b78937ff83f794dPete Cooper if (VRM) { 372e267ae7b8caf7192a3793eb3b78937ff83f794dPete Cooper VRM->grow(); 382e267ae7b8caf7192a3793eb3b78937ff83f794dPete Cooper VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg)); 392e267ae7b8caf7192a3793eb3b78937ff83f794dPete Cooper } 406a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen LiveInterval &LI = LIS.getOrCreateInterval(VReg); 416a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen newRegs_.push_back(&LI); 426a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen return LI; 43a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen} 44a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen 453b7d917dec53a742fcb14802557ee75d35185968Jakob Stoklund Olesenbool LiveRangeEdit::checkRematerializable(VNInfo *VNI, 462ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen const MachineInstr *DefMI, 472ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen AliasAnalysis *aa) { 482ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen assert(DefMI && "Missing instruction"); 492ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen scannedRemattable_ = true; 508a06af96698537377275dd7848db69915638dd26Pete Cooper if (!TII.isTriviallyReMaterializable(DefMI, aa)) 513b7d917dec53a742fcb14802557ee75d35185968Jakob Stoklund Olesen return false; 523b7d917dec53a742fcb14802557ee75d35185968Jakob Stoklund Olesen remattable_.insert(VNI); 533b7d917dec53a742fcb14802557ee75d35185968Jakob Stoklund Olesen return true; 542ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen} 552ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen 568a06af96698537377275dd7848db69915638dd26Pete Coopervoid LiveRangeEdit::scanRemattable(AliasAnalysis *aa) { 57080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen for (LiveInterval::vni_iterator I = parent_.vni_begin(), 58080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen E = parent_.vni_end(); I != E; ++I) { 59080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen VNInfo *VNI = *I; 60080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen if (VNI->isUnused()) 61080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen continue; 628a06af96698537377275dd7848db69915638dd26Pete Cooper MachineInstr *DefMI = LIS.getInstructionFromIndex(VNI->def); 63080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen if (!DefMI) 64080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen continue; 658a06af96698537377275dd7848db69915638dd26Pete Cooper checkRematerializable(VNI, DefMI, aa); 66080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen } 67806562cc59ad35e6c742abe9109e9b8090b3f820Jakob Stoklund Olesen scannedRemattable_ = true; 68080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen} 69080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 708a06af96698537377275dd7848db69915638dd26Pete Cooperbool LiveRangeEdit::anyRematerializable(AliasAnalysis *aa) { 71080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen if (!scannedRemattable_) 728a06af96698537377275dd7848db69915638dd26Pete Cooper scanRemattable(aa); 73080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen return !remattable_.empty(); 74080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen} 75080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 76a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen/// allUsesAvailableAt - Return true if all registers used by OrigMI at 77a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen/// OrigIdx are also available with the same value at UseIdx. 78a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesenbool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI, 79a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen SlotIndex OrigIdx, 808a06af96698537377275dd7848db69915638dd26Pete Cooper SlotIndex UseIdx) { 812debd48ca790ac01be6e12e094fdf4fdcadc8364Jakob Stoklund Olesen OrigIdx = OrigIdx.getRegSlot(true); 822debd48ca790ac01be6e12e094fdf4fdcadc8364Jakob Stoklund Olesen UseIdx = UseIdx.getRegSlot(true); 83a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen for (unsigned i = 0, e = OrigMI->getNumOperands(); i != e; ++i) { 84a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen const MachineOperand &MO = OrigMI->getOperand(i); 852ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen if (!MO.isReg() || !MO.getReg() || MO.isDef()) 86a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen continue; 87a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen // Reserved registers are OK. 888a06af96698537377275dd7848db69915638dd26Pete Cooper if (MO.isUndef() || !LIS.hasInterval(MO.getReg())) 89a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen continue; 90a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen 918a06af96698537377275dd7848db69915638dd26Pete Cooper LiveInterval &li = LIS.getInterval(MO.getReg()); 92a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen const VNInfo *OVNI = li.getVNInfoAt(OrigIdx); 93a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen if (!OVNI) 94a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen continue; 95a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen if (OVNI != li.getVNInfoAt(UseIdx)) 96a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen return false; 97a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen } 98a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen return true; 99a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen} 100a17768f5822ab62bc18608e5ba473187bf726b84Jakob Stoklund Olesen 101b80e973c95034e5754d888140497a9658a7c1dedJakob Stoklund Olesenbool LiveRangeEdit::canRematerializeAt(Remat &RM, 102b80e973c95034e5754d888140497a9658a7c1dedJakob Stoklund Olesen SlotIndex UseIdx, 1038a06af96698537377275dd7848db69915638dd26Pete Cooper bool cheapAsAMove) { 104080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen assert(scannedRemattable_ && "Call anyRematerializable first"); 105080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 106080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen // Use scanRemattable info. 107080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen if (!remattable_.count(RM.ParentVNI)) 108b80e973c95034e5754d888140497a9658a7c1dedJakob Stoklund Olesen return false; 109080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 1102ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen // No defining instruction provided. 1112ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen SlotIndex DefIdx; 1122ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen if (RM.OrigMI) 1138a06af96698537377275dd7848db69915638dd26Pete Cooper DefIdx = LIS.getInstructionIndex(RM.OrigMI); 1142ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen else { 1152ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen DefIdx = RM.ParentVNI->def; 1168a06af96698537377275dd7848db69915638dd26Pete Cooper RM.OrigMI = LIS.getInstructionFromIndex(DefIdx); 1172ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen assert(RM.OrigMI && "No defining instruction for remattable value"); 1182ef661b0e8de0d4186c5f9cc990adce0a2493b17Jakob Stoklund Olesen } 119080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 120080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen // If only cheap remats were requested, bail out early. 1215a96b3dad2f634c9081c8b2b6c2575441dc5a2bdEvan Cheng if (cheapAsAMove && !RM.OrigMI->isAsCheapAsAMove()) 122b80e973c95034e5754d888140497a9658a7c1dedJakob Stoklund Olesen return false; 123080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 124080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen // Verify that all used registers are available with the same values. 1258a06af96698537377275dd7848db69915638dd26Pete Cooper if (!allUsesAvailableAt(RM.OrigMI, DefIdx, UseIdx)) 126b80e973c95034e5754d888140497a9658a7c1dedJakob Stoklund Olesen return false; 127080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 128b80e973c95034e5754d888140497a9658a7c1dedJakob Stoklund Olesen return true; 129080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen} 130080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 131080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund OlesenSlotIndex LiveRangeEdit::rematerializeAt(MachineBasicBlock &MBB, 132080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen MachineBasicBlock::iterator MI, 133080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen unsigned DestReg, 134080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen const Remat &RM, 135bb30dd40ed0873e39fec4dfa321091a0c8d1abfcJakob Stoklund Olesen const TargetRegisterInfo &tri, 136bb30dd40ed0873e39fec4dfa321091a0c8d1abfcJakob Stoklund Olesen bool Late) { 137080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen assert(RM.OrigMI && "Invalid remat"); 1388a06af96698537377275dd7848db69915638dd26Pete Cooper TII.reMaterialize(MBB, MI, DestReg, 0, RM.OrigMI, tri); 139f1583ae84a8eeb0f6c0f81bd5bf189bdc9eaecb2Jakob Stoklund Olesen rematted_.insert(RM.ParentVNI); 1408a06af96698537377275dd7848db69915638dd26Pete Cooper return LIS.getSlotIndexes()->insertMachineInstrInMaps(--MI, Late) 1412debd48ca790ac01be6e12e094fdf4fdcadc8364Jakob Stoklund Olesen .getRegSlot(); 142080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen} 143080c316ff8a066cd164d9a8f92df509d8cb63110Jakob Stoklund Olesen 1448a06af96698537377275dd7848db69915638dd26Pete Coopervoid LiveRangeEdit::eraseVirtReg(unsigned Reg) { 1457792e980c43536814ea42448db9799b4da32fef6Jakob Stoklund Olesen if (delegate_ && delegate_->LRE_CanEraseVirtReg(Reg)) 1467792e980c43536814ea42448db9799b4da32fef6Jakob Stoklund Olesen LIS.removeInterval(Reg); 1477792e980c43536814ea42448db9799b4da32fef6Jakob Stoklund Olesen} 1487792e980c43536814ea42448db9799b4da32fef6Jakob Stoklund Olesen 1493520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesenbool LiveRangeEdit::foldAsLoad(LiveInterval *LI, 1508a06af96698537377275dd7848db69915638dd26Pete Cooper SmallVectorImpl<MachineInstr*> &Dead) { 1513520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen MachineInstr *DefMI = 0, *UseMI = 0; 1523520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen 1533520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen // Check that there is a single def and a single use. 1543520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen for (MachineRegisterInfo::reg_nodbg_iterator I = MRI.reg_nodbg_begin(LI->reg), 1553520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen E = MRI.reg_nodbg_end(); I != E; ++I) { 1563520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen MachineOperand &MO = I.getOperand(); 1573520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen MachineInstr *MI = MO.getParent(); 1583520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (MO.isDef()) { 1593520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (DefMI && DefMI != MI) 1603520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1615a96b3dad2f634c9081c8b2b6c2575441dc5a2bdEvan Cheng if (!MI->canFoldAsLoad()) 1623520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1633520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen DefMI = MI; 1643520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen } else if (!MO.isUndef()) { 1653520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (UseMI && UseMI != MI) 1663520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1673520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen // FIXME: Targets don't know how to fold subreg uses. 1683520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (MO.getSubReg()) 1693520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1703520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen UseMI = MI; 1713520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen } 1723520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen } 1733520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (!DefMI || !UseMI) 1743520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1753520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen 1763520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen DEBUG(dbgs() << "Try to fold single def: " << *DefMI 1773520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen << " into single use: " << *UseMI); 1783520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen 1793520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen SmallVector<unsigned, 8> Ops; 1803520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (UseMI->readsWritesVirtualRegister(LI->reg, &Ops).second) 1813520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1823520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen 1833520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen MachineInstr *FoldMI = TII.foldMemoryOperand(UseMI, Ops, DefMI); 1843520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen if (!FoldMI) 1853520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return false; 1863520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen DEBUG(dbgs() << " folded: " << *FoldMI); 1873520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen LIS.ReplaceMachineInstrInMaps(UseMI, FoldMI); 1883520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen UseMI->eraseFromParent(); 1893520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen DefMI->addRegisterDead(LI->reg, 0); 1903520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen Dead.push_back(DefMI); 191e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund Olesen ++NumDCEFoldedLoads; 1923520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen return true; 1933520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen} 1943520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen 1955881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesenvoid LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead, 1964777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper ArrayRef<unsigned> RegsBeingSpilled) { 1975881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen SetVector<LiveInterval*, 1985881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen SmallVector<LiveInterval*, 8>, 1995881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen SmallPtrSet<LiveInterval*, 8> > ToShrink; 2005881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2015881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen for (;;) { 2025881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen // Erase all dead defs. 2035881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen while (!Dead.empty()) { 2045881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen MachineInstr *MI = Dead.pop_back_val(); 2055881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen assert(MI->allDefsAreDead() && "Def isn't really dead"); 2062debd48ca790ac01be6e12e094fdf4fdcadc8364Jakob Stoklund Olesen SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot(); 2075881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2085881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen // Never delete inline asm. 209c46570dc05851395829bef904bb6ddb1260400d1Jakob Stoklund Olesen if (MI->isInlineAsm()) { 210c46570dc05851395829bef904bb6ddb1260400d1Jakob Stoklund Olesen DEBUG(dbgs() << "Won't delete: " << Idx << '\t' << *MI); 2115881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen continue; 212c46570dc05851395829bef904bb6ddb1260400d1Jakob Stoklund Olesen } 2135881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2145881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen // Use the same criteria as DeadMachineInstructionElim. 2155881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen bool SawStore = false; 216c46570dc05851395829bef904bb6ddb1260400d1Jakob Stoklund Olesen if (!MI->isSafeToMove(&TII, 0, SawStore)) { 217c46570dc05851395829bef904bb6ddb1260400d1Jakob Stoklund Olesen DEBUG(dbgs() << "Can't delete: " << Idx << '\t' << *MI); 2185881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen continue; 219c46570dc05851395829bef904bb6ddb1260400d1Jakob Stoklund Olesen } 2205881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2215881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen DEBUG(dbgs() << "Deleting dead def " << Idx << '\t' << *MI); 2225881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2235881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen // Check for live intervals that may shrink 2245881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen for (MachineInstr::mop_iterator MOI = MI->operands_begin(), 2255881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen MOE = MI->operands_end(); MOI != MOE; ++MOI) { 2265881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen if (!MOI->isReg()) 2275881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen continue; 2285881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen unsigned Reg = MOI->getReg(); 2295881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen if (!TargetRegisterInfo::isVirtualRegister(Reg)) 2305881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen continue; 2315881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen LiveInterval &LI = LIS.getInterval(Reg); 232cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen 2331edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen // Shrink read registers, unless it is likely to be expensive and 2341edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen // unlikely to change anything. We typically don't want to shrink the 2351edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen // PIC base register that has lots of uses everywhere. 2361edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen // Always shrink COPY uses that probably come from live range splitting. 2371edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen if (MI->readsVirtualRegister(Reg) && 2381edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen (MI->isCopy() || MOI->isDef() || MRI.hasOneNonDBGUse(Reg) || 2391edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen LI.killedAt(Idx))) 2405881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen ToShrink.insert(&LI); 241cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen 242cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen // Remove defined value. 243cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen if (MOI->isDef()) { 244cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen if (VNInfo *VNI = LI.getVNInfoAt(Idx)) { 2451e6c65dba706de80f5a4ceb8a1fc86bc3d0a61c6Jakob Stoklund Olesen if (delegate_) 2461e6c65dba706de80f5a4ceb8a1fc86bc3d0a61c6Jakob Stoklund Olesen delegate_->LRE_WillShrinkVirtReg(LI.reg); 247cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen LI.removeValNo(VNI); 248cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen if (LI.empty()) { 249cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen ToShrink.remove(&LI); 2508a06af96698537377275dd7848db69915638dd26Pete Cooper eraseVirtReg(Reg); 251cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen } 252cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen } 253cc5c4296fda7270e8394626d7254596f5f9c8d82Jakob Stoklund Olesen } 2545881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen } 2555881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 25692a55f4bdd120cdd3bb5a004c792d4d24a940311Jakob Stoklund Olesen if (delegate_) 25792a55f4bdd120cdd3bb5a004c792d4d24a940311Jakob Stoklund Olesen delegate_->LRE_WillEraseInstruction(MI); 2585881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen LIS.RemoveMachineInstrFromMaps(MI); 2595881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen MI->eraseFromParent(); 260e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund Olesen ++NumDCEDeleted; 2615881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen } 2625881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2635881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen if (ToShrink.empty()) 2645881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen break; 2655881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 2665881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen // Shrink just one live interval. Then delete new dead defs. 2671d5b84508173b93faf513032b3847152e6060791Jakob Stoklund Olesen LiveInterval *LI = ToShrink.back(); 2685881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen ToShrink.pop_back(); 2698a06af96698537377275dd7848db69915638dd26Pete Cooper if (foldAsLoad(LI, Dead)) 2703520019931c2bad615c35edcb943cd1e8582ebacJakob Stoklund Olesen continue; 2711d5b84508173b93faf513032b3847152e6060791Jakob Stoklund Olesen if (delegate_) 2721d5b84508173b93faf513032b3847152e6060791Jakob Stoklund Olesen delegate_->LRE_WillShrinkVirtReg(LI->reg); 2736a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen if (!LIS.shrinkToUses(LI, &Dead)) 2746a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen continue; 2754777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper 2764777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper // Don't create new intervals for a register being spilled. 2774777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper // The new intervals would have to be spilled anyway so its not worth it. 2784777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper // Also they currently aren't spilled so creating them and not spilling 2794777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper // them results in incorrect code. 2804777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper bool BeingSpilled = false; 2814777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper for (unsigned i = 0, e = RegsBeingSpilled.size(); i != e; ++i) { 2824777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper if (LI->reg == RegsBeingSpilled[i]) { 2834777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper BeingSpilled = true; 2844777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper break; 2854777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper } 2864777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper } 2874777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper 2884777ebb767d1b590c05d502c4a7f6adef4e6d5d1Pete Cooper if (BeingSpilled) continue; 2896a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen 2906a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen // LI may have been separated, create new intervals. 2916a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen LI->RenumberValues(LIS); 2926a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen ConnectedVNInfoEqClasses ConEQ(LIS); 2936a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen unsigned NumComp = ConEQ.Classify(LI); 2946a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen if (NumComp <= 1) 2956a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen continue; 296e9bd4ea5fda4957c373a3bbc14803d9670041dccJakob Stoklund Olesen ++NumFracRanges; 2972e267ae7b8caf7192a3793eb3b78937ff83f794dPete Cooper bool IsOriginal = VRM && VRM->getOriginal(LI->reg) == LI->reg; 2986a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen DEBUG(dbgs() << NumComp << " components: " << *LI << '\n'); 2996a3dbd3b25bbc99bd1a233d6a74ddea3493ba6acJakob Stoklund Olesen SmallVector<LiveInterval*, 8> Dups(1, LI); 300f22ca3fe5f0cfbb832cf41270f97cf5c0134fd7bJakob Stoklund Olesen for (unsigned i = 1; i != NumComp; ++i) { 3018a06af96698537377275dd7848db69915638dd26Pete Cooper Dups.push_back(&createFrom(LI->reg)); 3029693d4c3f0d0e8c91e4748eb1c18799b1de7551cJakob Stoklund Olesen // If LI is an original interval that hasn't been split yet, make the new 3039693d4c3f0d0e8c91e4748eb1c18799b1de7551cJakob Stoklund Olesen // intervals their own originals instead of referring to LI. The original 3049693d4c3f0d0e8c91e4748eb1c18799b1de7551cJakob Stoklund Olesen // interval must contain all the split products, and LI doesn't. 3059693d4c3f0d0e8c91e4748eb1c18799b1de7551cJakob Stoklund Olesen if (IsOriginal) 3068a06af96698537377275dd7848db69915638dd26Pete Cooper VRM->setIsSplitFromReg(Dups.back()->reg, 0); 307f22ca3fe5f0cfbb832cf41270f97cf5c0134fd7bJakob Stoklund Olesen if (delegate_) 308f22ca3fe5f0cfbb832cf41270f97cf5c0134fd7bJakob Stoklund Olesen delegate_->LRE_DidCloneVirtReg(Dups.back()->reg, LI->reg); 309f22ca3fe5f0cfbb832cf41270f97cf5c0134fd7bJakob Stoklund Olesen } 3101edc3cf65d54130542fc91bac67ecf616ef88d48Jakob Stoklund Olesen ConEQ.Distribute(&Dups[0], MRI); 3115881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen } 3125881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen} 3135881799d0cccbd814ec1b0f0509df9be1f63c6cbJakob Stoklund Olesen 3146094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesenvoid LiveRangeEdit::calculateRegClassAndHint(MachineFunction &MF, 3156094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen const MachineLoopInfo &Loops) { 3166094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen VirtRegAuxInfo VRAI(MF, LIS, Loops); 3176094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen for (iterator I = begin(), E = end(); I != E; ++I) { 3186094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen LiveInterval &LI = **I; 3196d1fd0b979cb88809ebb77a24f4da69e1d67606bJakob Stoklund Olesen if (MRI.recomputeRegClass(LI.reg, MF.getTarget())) 3206d1fd0b979cb88809ebb77a24f4da69e1d67606bJakob Stoklund Olesen DEBUG(dbgs() << "Inflated " << PrintReg(LI.reg) << " to " 3216d1fd0b979cb88809ebb77a24f4da69e1d67606bJakob Stoklund Olesen << MRI.getRegClass(LI.reg)->getName() << '\n'); 3226094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen VRAI.CalculateWeightAndHint(LI); 3236094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen } 3246094bd87d845afabba5b99ec4848fa6116bac682Jakob Stoklund Olesen} 325