Add a GC plugin for Erlang
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177867 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ErlangGC.cpp b/lib/CodeGen/ErlangGC.cpp
new file mode 100644
index 0000000..8a1e2d9
--- /dev/null
+++ b/lib/CodeGen/ErlangGC.cpp
@@ -0,0 +1,81 @@
+//===-- 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"
+
+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);
+ };
+
+}
+
+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()->getTarget().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;
+}