[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/base-pointers-4.ll b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-4.ll
index 9faaefb..4e0bb14 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-4.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-4.ll
@@ -13,10 +13,10 @@
 
 loop:
 ; CHECK: loop:
-; CHECK:  %safepoint_token1 = call i32 (i64, i32, i64 addrspace(1)* ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_p1i64f(i64 0, i32 0, i64 addrspace(1)* ()* @generate_obj, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i3
+; CHECK:  %safepoint_token1 = call token (i64, i32, i64 addrspace(1)* ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_p1i64f(i64 0, i32 0, i64 addrspace(1)* ()* @generate_obj, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i3
 ; CHECK-NEXT:  %obj2 = call i64 addrspace(1)* @llvm.experimental.gc.result
-  %safepoint_token1 = call i32 (i64, i32, i64 addrspace(1)* ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_p1i64f(i64 0, i32 0, i64 addrspace(1)* ()* @generate_obj, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
-  %obj2 = call i64 addrspace(1)* @llvm.experimental.gc.result.p1i64(i32 %safepoint_token1)
+  %safepoint_token1 = call token (i64, i32, i64 addrspace(1)* ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_p1i64f(i64 0, i32 0, i64 addrspace(1)* ()* @generate_obj, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
+  %obj2 = call i64 addrspace(1)* @llvm.experimental.gc.result.p1i64(token %safepoint_token1)
   switch i32 %condition, label %dest_a [
     i32 0, label %dest_b
     i32 1, label %dest_c
@@ -36,17 +36,17 @@
 ; CHECK:  %obj_to_consume = phi i64 addrspace(1)* [ %obj2, %dest_a ], [ null, %dest_b ], [ null, %dest_c ]
 
   %obj_to_consume = phi i64 addrspace(1)* [ %obj2, %dest_a ], [ null, %dest_b ], [ null, %dest_c ]
-  %safepoint_token3 = call i32 (i64, i32, void (i64 addrspace(1)*)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(i64 0, i32 0, void (i64 addrspace(1)*)* @consume_obj, i32 1, i32 0, i64 addrspace(1)* %obj_to_consume, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
+  %safepoint_token3 = call token (i64, i32, void (i64 addrspace(1)*)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(i64 0, i32 0, void (i64 addrspace(1)*)* @consume_obj, i32 1, i32 0, i64 addrspace(1)* %obj_to_consume, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
   br label %merge.split
 
 merge.split:                                      ; preds = %merge
-  %safepoint_token = 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 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
+  %safepoint_token = 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 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
   br label %loop
 }
 
 
 ; Function Attrs: nounwind
-declare i64 addrspace(1)* @llvm.experimental.gc.result.p1i64(i32) #0
-declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
-declare i32 @llvm.experimental.gc.statepoint.p0f_p1i64f(i64, i32, i64 addrspace(1)* ()*, i32, i32, ...)
-declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(i64, i32, void (i64 addrspace(1)*)*, i32, i32, ...)
+declare i64 addrspace(1)* @llvm.experimental.gc.result.p1i64(token) #0
+declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
+declare token @llvm.experimental.gc.statepoint.p0f_p1i64f(i64, i32, i64 addrspace(1)* ()*, i32, i32, ...)
+declare token @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(i64, i32, void (i64 addrspace(1)*)*, i32, i32, ...)