//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "regalloc"
#include "Spiller.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LiveRangeEdit.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
+#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
using namespace llvm;
+#define DEBUG_TYPE "regalloc"
+
STATISTIC(NumSpilledRanges, "Number of spilled live ranges");
STATISTIC(NumSnippets, "Number of spilled snippets");
STATISTIC(NumSpills, "Number of spills inserted");
SibValueInfo(unsigned Reg, VNInfo *VNI)
: AllDefsAreReloads(true), DefByOrigPHI(false), KillsSource(false),
- SpillReg(Reg), SpillVNI(VNI), SpillMBB(0), DefMI(0) {}
+ SpillReg(Reg), SpillVNI(VNI), SpillMBB(nullptr), DefMI(nullptr) {}
// Returns true when a def has been found.
bool hasDef() const { return DefByOrigPHI || DefMI; }
// Dead defs generated during spilling.
SmallVector<MachineInstr*, 8> DeadDefs;
- ~InlineSpiller() {}
+ ~InlineSpiller() override {}
public:
- InlineSpiller(MachineFunctionPass &pass,
- MachineFunction &mf,
- VirtRegMap &vrm)
- : MF(mf),
- LIS(pass.getAnalysis<LiveIntervals>()),
- LSS(pass.getAnalysis<LiveStacks>()),
- AA(&pass.getAnalysis<AliasAnalysis>()),
- MDT(pass.getAnalysis<MachineDominatorTree>()),
- Loops(pass.getAnalysis<MachineLoopInfo>()),
- VRM(vrm),
- MFI(*mf.getFrameInfo()),
- MRI(mf.getRegInfo()),
- TII(*mf.getTarget().getInstrInfo()),
- TRI(*mf.getTarget().getRegisterInfo()),
- MBFI(pass.getAnalysis<MachineBlockFrequencyInfo>()) {}
+ InlineSpiller(MachineFunctionPass &pass, MachineFunction &mf, VirtRegMap &vrm)
+ : MF(mf), LIS(pass.getAnalysis<LiveIntervals>()),
+ LSS(pass.getAnalysis<LiveStacks>()),
+ AA(&pass.getAnalysis<AliasAnalysis>()),
+ MDT(pass.getAnalysis<MachineDominatorTree>()),
+ Loops(pass.getAnalysis<MachineLoopInfo>()), VRM(vrm),
+ MFI(*mf.getFrameInfo()), MRI(mf.getRegInfo()),
+ TII(*mf.getSubtarget().getInstrInfo()),
+ TRI(*mf.getSubtarget().getRegisterInfo()),
+ MBFI(pass.getAnalysis<MachineBlockFrequencyInfo>()) {}
void spill(LiveRangeEdit &) override;
bool isSibling(unsigned Reg);
MachineInstr *traceSiblingValue(unsigned, VNInfo*, VNInfo*);
- void propagateSiblingValue(SibValueMap::iterator, VNInfo *VNI = 0);
+ void propagateSiblingValue(SibValueMap::iterator, VNInfo *VNI = nullptr);
void analyzeSiblingValues();
bool hoistSpill(LiveInterval &SpillLI, MachineInstr *CopyMI);
bool coalesceStackAccess(MachineInstr *MI, unsigned Reg);
bool foldMemoryOperand(ArrayRef<std::pair<MachineInstr*, unsigned> >,
- MachineInstr *LoadMI = 0);
+ MachineInstr *LoadMI = nullptr);
void insertReload(unsigned VReg, SlotIndex, MachineBasicBlock::iterator MI);
void insertSpill(unsigned VReg, bool isKill, MachineBasicBlock::iterator MI);
}
namespace llvm {
+
+Spiller::~Spiller() { }
+void Spiller::anchor() { }
+
Spiller *createInlineSpiller(MachineFunctionPass &pass,
MachineFunction &mf,
VirtRegMap &vrm) {
return new InlineSpiller(pass, mf, vrm);
}
+
}
//===----------------------------------------------------------------------===//
if (SnipLI.getNumValNums() > 2 || !LIS.intervalIsInOneMBB(SnipLI))
return false;
- MachineInstr *UseMI = 0;
+ MachineInstr *UseMI = nullptr;
// Check that all uses satisfy our criteria.
for (MachineRegisterInfo::reg_instr_nodbg_iterator
do {
SVI = WorkList.pop_back_val();
TinyPtrVector<VNInfo*> *Deps = VNI ? &FirstDeps : &SVI->second.Deps;
- VNI = 0;
+ VNI = nullptr;
SibValueInfo &SV = SVI->second;
if (!SV.SpillMBB)
// Also hoist spills to blocks with smaller loop depth, but make sure
// that the new value dominates. Non-phi dependents are always
// dominated, phis need checking.
+
+ const BranchProbability MarginProb(4, 5); // 80%
+ // Hoist a spill to outer loop if there are multiple dependents (it
+ // can be beneficial if more than one dependents are hoisted) or
+ // if DepSV (the hoisting source) is hotter than SV (the hoisting
+ // destination) (we add a 80% margin to bias a little towards
+ // loop depth).
+ bool HoistCondition =
+ (MBFI.getBlockFreq(DepSV.SpillMBB) >=
+ (MBFI.getBlockFreq(SV.SpillMBB) * MarginProb)) ||
+ Deps->size() > 1;
+
if ((Loops.getLoopDepth(DepSV.SpillMBB) > SpillDepth) &&
+ HoistCondition &&
(!DepSVI->first->isPHIDef() ||
MDT.dominates(SV.SpillMBB, DepSV.SpillMBB))) {
Changed = true;
SmallVector<std::pair<unsigned, VNInfo*>, 8> WorkList;
WorkList.push_back(std::make_pair(UseReg, UseVNI));
+ LiveInterval &OrigLI = LIS.getInterval(Original);
do {
unsigned Reg;
VNInfo *VNI;
// Trace through PHI-defs created by live range splitting.
if (VNI->isPHIDef()) {
- // Stop at original PHIs. We don't know the value at the predecessors.
- if (VNI->def == OrigVNI->def) {
+ // Stop at original PHIs. We don't know the value at the
+ // predecessors. Look up the VNInfo for the current definition
+ // in OrigLI, to properly determine whether or not this phi was
+ // added by splitting.
+ if (VNI->def == OrigLI.getVNInfoAt(VNI->def)->def) {
DEBUG(dbgs() << "orig phi value\n");
SVI->second.DefByOrigPHI = true;
SVI->second.AllDefsAreReloads = false;
// Separate all values dominated by OrigVNI into PHIs and non-PHIs.
SmallVector<VNInfo*, 8> PHIs, NonPHIs;
LiveInterval &LI = LIS.getInterval(Reg);
- LiveInterval &OrigLI = LIS.getInterval(Original);
for (LiveInterval::vni_iterator VI = LI.vni_begin(), VE = LI.vni_end();
VI != VE; ++VI) {
std::tie(SVI, Inserted) =
SibValues.insert(std::make_pair(NonPHI, SibValueInfo(Reg, NonPHI)));
// Add all the PHIs as dependents of NonPHI.
- for (unsigned pi = 0, pe = PHIs.size(); pi != pe; ++pi)
- SVI->second.Deps.push_back(PHIs[pi]);
+ SVI->second.Deps.insert(SVI->second.Deps.end(), PHIs.begin(),
+ PHIs.end());
// This is the first time we see NonPHI, add it to the worklist.
if (Inserted)
WorkList.push_back(std::make_pair(Reg, NonPHI));
VNInfo *VNI = *VI;
if (VNI->isUnused())
continue;
- MachineInstr *DefMI = 0;
+ MachineInstr *DefMI = nullptr;
if (!VNI->isPHIDef()) {
DefMI = LIS.getInstructionFromIndex(VNI->def);
assert(DefMI && "No defining instruction");
WorkList.push_back(std::make_pair(LI, VNI));
do {
std::tie(LI, VNI) = WorkList.pop_back_val();
- if (!UsedValues.insert(VNI))
+ if (!UsedValues.insert(VNI).second)
continue;
if (VNI->isPHIDef()) {
/// reMaterializeFor - Attempt to rematerialize before MI instead of reloading.
bool InlineSpiller::reMaterializeFor(LiveInterval &VirtReg,
MachineBasicBlock::iterator MI) {
+
+ // Analyze instruction
+ SmallVector<std::pair<MachineInstr *, unsigned>, 8> Ops;
+ MIBundleOperands::VirtRegInfo RI =
+ MIBundleOperands(MI).analyzeVirtReg(VirtReg.reg, &Ops);
+
+ if (!RI.Reads)
+ return false;
+
SlotIndex UseIdx = LIS.getInstructionIndex(MI).getRegSlot(true);
VNInfo *ParentVNI = VirtReg.getVNInfoAt(UseIdx.getBaseIndex());
// If the instruction also writes VirtReg.reg, it had better not require the
// same register for uses and defs.
- SmallVector<std::pair<MachineInstr*, unsigned>, 8> Ops;
- MIBundleOperands::VirtRegInfo RI =
- MIBundleOperands(MI).analyzeVirtReg(VirtReg.reg, &Ops);
if (RI.Tied) {
markValueUsed(&VirtReg, ParentVNI);
DEBUG(dbgs() << "\tcannot remat tied reg: " << UseIdx << '\t' << *MI);
for (unsigned i = 0, e = RegsToSpill.size(); i != e; ++i) {
unsigned Reg = RegsToSpill[i];
LiveInterval &LI = LIS.getInterval(Reg);
- for (MachineRegisterInfo::use_bundle_nodbg_iterator
- RI = MRI.use_bundle_nodbg_begin(Reg), E = MRI.use_bundle_nodbg_end();
- RI != E; ) {
- MachineInstr *MI = &*(RI++);
+ for (MachineRegisterInfo::reg_bundle_iterator
+ RegI = MRI.reg_bundle_begin(Reg), E = MRI.reg_bundle_end();
+ RegI != E; ) {
+ MachineInstr *MI = &*(RegI++);
+
+ // Debug values are not allowed to affect codegen.
+ if (MI->isDebugValue())
+ continue;
+
anyRemat |= reMaterializeFor(LI, MI);
}
}
bool WasCopy = MI->isCopy();
unsigned ImpReg = 0;
- bool SpillSubRegs = (MI->getOpcode() == TargetOpcode::PATCHPOINT ||
+ bool SpillSubRegs = (MI->getOpcode() == TargetOpcode::STATEPOINT ||
+ MI->getOpcode() == TargetOpcode::PATCHPOINT ||
MI->getOpcode() == TargetOpcode::STACKMAP);
// TargetInstrInfo::foldMemoryOperand only expects explicit, non-tied
continue;
// FoldMI does not define this physreg. Remove the LI segment.
assert(MO->isDead() && "Cannot fold physreg def");
- for (MCRegUnitIterator Units(Reg, &TRI); Units.isValid(); ++Units) {
- if (LiveRange *LR = LIS.getCachedRegUnit(*Units)) {
- SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot();
- if (VNInfo *VNI = LR->getVNInfoAt(Idx))
- LR->removeValNo(VNI);
- }
- }
+ SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot();
+ LIS.removePhysRegDefAt(Reg, Idx);
}
LIS.ReplaceMachineInstrInMaps(MI, FoldMI);
// Modify DBG_VALUE now that the value is in a spill slot.
bool IsIndirect = MI->isIndirectDebugValue();
uint64_t Offset = IsIndirect ? MI->getOperand(1).getImm() : 0;
- const MDNode *MDPtr = MI->getOperand(2).getMetadata();
+ const MDNode *Var = MI->getDebugVariable();
+ const MDNode *Expr = MI->getDebugExpression();
DebugLoc DL = MI->getDebugLoc();
DEBUG(dbgs() << "Modifying debug info due to spill:" << "\t" << *MI);
MachineBasicBlock *MBB = MI->getParent();
+ assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
+ "Expected inlined-at fields to agree");
BuildMI(*MBB, MBB->erase(MI), DL, TII.get(TargetOpcode::DBG_VALUE))
- .addFrameIndex(StackSlot).addImm(Offset).addMetadata(MDPtr);
+ .addFrameIndex(StackSlot)
+ .addImm(Offset)
+ .addMetadata(Var)
+ .addMetadata(Expr);
continue;
}
// Share a stack slot among all descendants of Original.
Original = VRM.getOriginal(edit.getReg());
StackSlot = VRM.getStackSlot(Original);
- StackInt = 0;
+ StackInt = nullptr;
DEBUG(dbgs() << "Inline spilling "
- << MRI.getRegClass(edit.getReg())->getName()
+ << TRI.getRegClassName(MRI.getRegClass(edit.getReg()))
<< ':' << edit.getParent()
<< "\nFrom original " << PrintReg(Original) << '\n');
assert(edit.getParent().isSpillable() &&
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