Add a GCStrategy for CoreCLR
This change adds a new GC strategy for supporting the CoreCLR runtime.
This strategy is currently identical to Statepoint-example GC,
but is necessary for several upcoming changes specific to CoreCLR, such as:
1. Base-pointers not explicitly reported for interior pointers
2. Different format for stack-map encoding
3. Location of Safe-point polls: polls are only needed before loop-back edges and before tail-calls (not needed at function-entry)
4. Runtime specific handshake between calls to managed/unmanaged functions.
llvm-svn: 237753
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
index 6ce5b13..9fc3e0b 100644
--- a/llvm/lib/CodeGen/CMakeLists.txt
+++ b/llvm/lib/CodeGen/CMakeLists.txt
@@ -9,6 +9,7 @@
CallingConvLower.cpp
CodeGen.cpp
CodeGenPrepare.cpp
+ CoreCLRGC.cpp
CriticalAntiDepBreaker.cpp
DFAPacketizer.cpp
DeadMachineInstructionElim.cpp
diff --git a/llvm/lib/CodeGen/CoreCLRGC.cpp b/llvm/lib/CodeGen/CoreCLRGC.cpp
new file mode 100644
index 0000000..2726180
--- /dev/null
+++ b/llvm/lib/CodeGen/CoreCLRGC.cpp
@@ -0,0 +1,55 @@
+//===-- CoreCLRGC.cpp - CoreCLR Runtime GC Strategy -----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a GCStrategy for the CoreCLR Runtime.
+// The strategy is similar to Statepoint-example GC, but differs from it in
+// certain aspects, such as:
+// 1) Base-pointers need not be explicitly tracked and reported for
+// interior pointers
+// 2) Uses a different format for encoding stack-maps
+// 3) Location of Safe-point polls: polls are only needed before loop-back edges
+// and before tail-calls (not needed at function-entry)
+//
+// The above differences in behavior are to be implemented in upcoming checkins.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/GCStrategy.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Value.h"
+
+using namespace llvm;
+
+namespace {
+class CoreCLRGC : public GCStrategy {
+public:
+ CoreCLRGC() {
+ UseStatepoints = true;
+ // These options are all gc.root specific, we specify them so that the
+ // gc.root lowering code doesn't run.
+ InitRoots = false;
+ NeededSafePoints = 0;
+ UsesMetadata = false;
+ CustomRoots = false;
+ }
+ Optional<bool> isGCManagedPointer(const Value *V) const override {
+ // Method is only valid on pointer typed values.
+ PointerType *PT = cast<PointerType>(V->getType());
+ // We pick addrspace(1) as our GC managed heap.
+ return (1 == PT->getAddressSpace());
+ }
+};
+}
+
+static GCRegistry::Add<CoreCLRGC> X("coreclr",
+ "CoreCLR-compatible GC");
+
+namespace llvm {
+void linkCoreCLRGC() {}
+}