[IR] Fix creating mutable versions of TBAA access tags

[kosarev]

Summary

Due to a typo in D41565, mutable TBAA tags created with createMutableTBAAAccessTag() lose their base types. This patch fixes that typo and updates tests respectively.

[kosarev]

Ping.

[kosarev]

Ping.

[kosarev]

Ping.

[apilipenko]

Thanks for adding the test case!

lib/IR/MDBuilder.cpp

if (IsImmutable) {
     auto *ImmutabilityFlagNode = createConstant(ConstantInt::get(Int64, 1));
     return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode,
                                  ImmutabilityFlagNode});
   }
   return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode});
 }
 
 MDNode *MDBuilder::createMutableTBAAAccessTag(MDNode *Tag) {
-  MDNode *BaseType = cast<MDNode>(Tag->getOperand(1));
+  MDNode *BaseType = cast<MDNode>(Tag->getOperand(0));
   MDNode *AccessType = cast<MDNode>(Tag->getOperand(1));
   Metadata *OffsetNode = Tag->getOperand(2);
   uint64_t Offset = mdconst::extract<ConstantInt>(OffsetNode)->getZExtValue();
 
   bool NewFormat = isa<MDNode>(AccessType->getOperand(0));
 
   // See if the tag is already mutable.
   unsigned ImmutabilityFlagOp = NewFormat ? 4 : 3;

test/Transforms/RewriteStatepointsForGC/deref-pointers.ll

entry:
   ret i8 %tmp
 }
 
 ; Same as test_md() above, but with new-format TBAA metadata.
 define i8 @test_md_new(i8 addrspace(1)* %ptr) gc "statepoint-example" {
 ; CHECK-LABEL: @test_md_new(
 ; CHECK: %tmp = load i8, i8 addrspace(1)* %ptr, !tbaa [[TAG_new:!.*]]
 entry:
-  %tmp = load i8, i8 addrspace(1)* %ptr, !tbaa !3
+  %tmp = load i8, i8 addrspace(1)* %ptr, !tbaa !4
   call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ]
   ret i8 %tmp
 }
 
 define i8 addrspace(1)* @test_decl_only_attribute(i8 addrspace(1)* %ptr) gc "statepoint-example" {
 ; CHECK-LABEL: @test_decl_only_attribute(
 ; No change here, but the prototype of some_function_ret_deref should have changed.
 ; CHECK: call i8 addrspace(1)* @some_function_ret_deref()

 ; CHECK-LABEL: @test_callsite_arg_attribute(
 ; CHECK: call void @some_function_consumer(i8 addrspace(1)* %ptr)
 entry:
   call void @some_function_consumer(i8 addrspace(1)* dereferenceable(4) noalias %ptr)
   call void @foo() [ "deopt"(i32 0, i32 -1, i32 0, i32 0, i32 0) ]
   ret i8 addrspace(1)* %ptr
 }
 
-!0 = !{!1, !1, i64 0, i64 1}  ; TAG_old
-!1 = !{!"type_old", !2}
-!2 = !{!"root"}
-
-!3 = !{!4, !4, i64 0, i64 1, i64 1}  ; TAG_new
-!4 = !{!2, i64 1, !"type_new"}
+!0 = !{!1, !2, i64 0, i64 1}  ; TAG_old
+!1 = !{!"type_base_old", !2, i64 0}
+!2 = !{!"type_access_old", !3}
+!3 = !{!"root"}
+
+!4 = !{!5, !6, i64 0, i64 1, i64 1}  ; TAG_new
+!5 = !{!3, i64 1, !"type_base_new", !6, i64 0, i64 1}
+!6 = !{!3, i64 1, !"type_access_new"}
 
 ; CHECK-DAG: [[ROOT:!.*]] = !{!"root"}
-; CHECK-DAG: [[TYPE_old:!.*]] = !{!"type_old", [[ROOT]]}
-; CHECK-DAG: [[TAG_old]] = !{[[TYPE_old]], [[TYPE_old]], i64 0}
-; CHECK-DAG: [[TYPE_new:!.*]] = !{[[ROOT]], i64 1, !"type_new"}
-; CHECK-DAG: [[TAG_new]] = !{[[TYPE_new]], [[TYPE_new]], i64 0, i64 1}
+; CHECK-DAG: [[TYPE_access_old:!.*]] = !{!"type_access_old", [[ROOT]]}
+; CHECK-DAG: [[TYPE_base_old:!.*]] = !{!"type_base_old", [[TYPE_access_old]], i64 0}
+; CHECK-DAG: [[TAG_old]] = !{[[TYPE_base_old]], [[TYPE_access_old]], i64 0}
+; CHECK-DAG: [[TYPE_access_new:!.*]] = !{[[ROOT]], i64 1, !"type_access_new"}
+; CHECK-DAG: [[TYPE_base_new:!.*]] = !{[[ROOT]], i64 1, !"type_base_new", [[TYPE_access_new]], i64 0, i64 1}
+; CHECK-DAG: [[TAG_new]] = !{[[TYPE_base_new]], [[TYPE_access_new]], i64 0, i64 1}