llvm/lib/CodeGen/ErlangGC.cpp
Eric Christopher 6035518e3b Have MachineFunction cache a pointer to the subtarget to make lookups
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.

Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214838 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-05 02:39:49 +00:00

83 lines
2.6 KiB
C++

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