forked from OSchip/llvm-project
82 lines
2.5 KiB
C++
82 lines
2.5 KiB
C++
//===-- ErlangGC.cpp - Erlang/OTP GC strategy -------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the Erlang/OTP runtime-compatible garbage collector
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// (e.g. defines safe points, root initialization etc.)
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//
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// The frametable emitter is in ErlangGCPrinter.cpp.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/GCs.h"
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#include "llvm/CodeGen/GCStrategy.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/Target/TargetInstrInfo.h"
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#include "llvm/Target/TargetMachine.h"
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using namespace llvm;
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namespace {
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class ErlangGC : public GCStrategy {
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MCSymbol *InsertLabel(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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DebugLoc DL) const;
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public:
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ErlangGC();
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bool findCustomSafePoints(GCFunctionInfo &FI, MachineFunction &MF);
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};
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}
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static GCRegistry::Add<ErlangGC>
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X("erlang", "erlang-compatible garbage collector");
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void llvm::linkErlangGC() { }
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ErlangGC::ErlangGC() {
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InitRoots = false;
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NeededSafePoints = 1 << GC::PostCall;
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UsesMetadata = true;
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CustomRoots = false;
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CustomSafePoints = true;
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}
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MCSymbol *ErlangGC::InsertLabel(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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DebugLoc DL) const {
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const TargetInstrInfo* TII = MBB.getParent()->getTarget().getInstrInfo();
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MCSymbol *Label = MBB.getParent()->getContext().CreateTempSymbol();
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BuildMI(MBB, MI, DL, TII->get(TargetOpcode::GC_LABEL)).addSym(Label);
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return Label;
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}
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bool ErlangGC::findCustomSafePoints(GCFunctionInfo &FI, MachineFunction &MF) {
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for (MachineFunction::iterator BBI = MF.begin(), BBE = MF.end(); BBI != BBE;
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++BBI)
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for (MachineBasicBlock::iterator MI = BBI->begin(), ME = BBI->end();
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MI != ME; ++MI)
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if (MI->getDesc().isCall()) {
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// Do not treat tail call sites as safe points.
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if (MI->getDesc().isTerminator())
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continue;
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/* Code copied from VisitCallPoint(...) */
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MachineBasicBlock::iterator RAI = MI; ++RAI;
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MCSymbol* Label = InsertLabel(*MI->getParent(), RAI, MI->getDebugLoc());
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FI.addSafePoint(GC::PostCall, Label, MI->getDebugLoc());
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}
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return false;
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}
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