[gc.statepoint] Change gc.statepoint intrinsic's return type to token type instead of i32 type

Summary: This patch changes gc.statepoint intrinsic's return type to token type instead of i32 type. Using token types could prevent LLVM to merge different gc.statepoint nodes into PHI nodes and cause further problems with gc relocations. The patch also changes the way on how gc.relocate and gc.result look for their corresponding gc.statepoint on unwind path. The current implementation uses the selector value extracted from a { i8*, i32 } landingpad as a hook to find the gc.statepoint, while the patch directly uses a token type landingpad (http://reviews.llvm.org/D15405) to find the gc.statepoint. 

Reviewers: sanjoy, JosephTremoulet, pgavlin, igor-laevsky, mjacob

Subscribers: reames, mjacob, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D15662

llvm-svn: 256443
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll b/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
index 012fff5..e165749 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
@@ -17,7 +17,7 @@
 ; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated.casted)
 ; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated.casted)
   %obj2 = phi i64 addrspace(1)* [ %obj, %entry ]
-  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
+  call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
   call void (...) @consume(i64 addrspace(1)* %obj2)
   call void (...) @consume(i64 addrspace(1)* %obj)
   ret void
@@ -33,7 +33,7 @@
 
 unreached:
   %obj = phi i64 addrspace(1)* [null, %unreached]
-  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
+  call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
   call void (...) @consume(i64 addrspace(1)* %obj)
   br label %unreached
 }
@@ -46,7 +46,7 @@
   ret void
 
 unreached:
-  invoke i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
+  invoke token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
           to label %normal_return unwind label %exceptional_return
 
 normal_return:                                    ; preds = %entry
@@ -62,4 +62,4 @@
 ; Bound the last check-not
 ; CHECK-LABEL: @foo
 
-declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
+declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)