[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/preprocess.ll b/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
index ffdfe5b..39567b1 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
@@ -13,8 +13,9 @@
; CHECK-LABEL: next:
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: gc.relocate
-; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated)
-; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated)
+; CHECK-NEXT: bitcast
+; 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 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, i32 0, i32 0, i32 0)
call void (...) @consume(i64 addrspace(1)* %obj2)