1 files changed, 81 insertions, 0 deletions
diff --git a/lib/CodeGen/ErlangGC.cpp b/lib/CodeGen/ErlangGC.cpp
new file mode 100644
index 0000000000..8a1e2d9c99
--- /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;
+}