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

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp b/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp
index fc1453b3175..9e7a4d8febc 100644
--- a/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp
+++ b/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp
@@ -53,6 +53,7 @@
 #include "llvm/ADT/SetOperations.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/ScalarEvolution.h"
@@ -523,8 +524,11 @@ static bool isGCSafepointPoll(Function &F) {
 static bool shouldRewriteFunction(Function &F) {
   // TODO: This should check the GCStrategy
   if (F.hasGC()) {
-    const std::string StatepointExampleName("statepoint-example");
-    return StatepointExampleName == F.getGC();
+    const char *FunctionGCName = F.getGC();

+    const StringRef StatepointExampleName("statepoint-example");

+    const StringRef CoreCLRName("coreclr");

+    return (StatepointExampleName == FunctionGCName) ||

+      (CoreCLRName == FunctionGCName);
   } else
     return false;
 }