[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
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll
index e88f6df..2652d36 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll
@@ -13,7 +13,7 @@
loop:
; CHECK: phi i64 addrspace(1)*
-; CHECK-DAG: [ %obj.relocated, %loop ]
+; CHECK-DAG: [ %obj.relocated.casted, %loop ]
; CHECK-DAG: [ %obj, %entry ]
call void @use_obj(i64 addrspace(1)* %obj)
%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)
@@ -78,7 +78,7 @@
; CHECK-DAG: [ %base_obj, %entry ]
; Given the two selects are equivelent, so are their base phis - ideally,
; we'd have commoned these, but that's a missed optimization, not correctness.
-; CHECK-DAG: [ [[DISCARD:%base_select.*.relocated]], %loop ]
+; CHECK-DAG: [ [[DISCARD:%base_select.*.relocated.casted]], %loop ]
; CHECK-NOT: base_phi2
; CHECK: next = select
; CHECK: base_select