[RewriteStatepointsForGC] Fix a bug on creating gc_relocate for pointer to vector of pointers

Summary:
In RewriteStatepointsForGC pass, we create a gc_relocate intrinsic for
each relocated pointer, and the gc_relocate has the same type with the
pointer. During the creation of gc_relocate intrinsic, llvm requires to
mangle its type. However, llvm does not support mangling of all possible
types. RewriteStatepointsForGC will hit an assertion failure when it
tries to create a gc_relocate for pointer to vector of pointers because
mangling for vector of pointers is not supported.

This patch changes the way RewriteStatepointsForGC pass creates
gc_relocate. For each relocated pointer, we erase the type of pointers
and create an unified gc_relocate of type i8 addrspace(1)*. Then a
bitcast is inserted to convert the gc_relocate to the correct type. In
this way, gc_relocate does not need to deal with different types of
pointers and the unsupported type mangling is no longer a problem. This
change would also ease further merge when LLVM erases types of pointers
and introduces an unified pointer type.

Some minor changes are also introduced to gc_relocate related part in
InstCombineCalls, CodeGenPrepare, and Verifier accordingly.

Patch by Chen Li!

Reviewers: reames, AndyAyers, sanjoy

Reviewed By: sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9592

llvm-svn: 237009

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll
index 2fc9d42ee1f..11e252f43aa 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll
@@ -12,11 +12,11 @@ entry:
 loop:                                             ; preds = %loop, %entry
 ; CHECK-LABEL: loop:
 ; CHECK: phi i64 addrspace(1)*
-; CHECK-DAG:  [ %base_obj.relocated, %loop ] 
+; CHECK-DAG:  [ %base_obj.relocated.casted, %loop ] 
 ; CHECK-DAG:  [ %base_obj, %entry ]
 ; CHECK:  %current = phi i64 addrspace(1)* 
 ; CHECK-DAG:  [ %obj, %entry ]
-; CHECK-DAG:  [ %next.relocated, %loop ]
+; CHECK-DAG:  [ %next.relocated.casted, %loop ]
   %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ]
   %next = getelementptr i64, i64 addrspace(1)* %current, i32 1
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)