MS ABI: Emit more canonical vbptr stores and loads
This eliminates some i8* GEPs and makes the IR that clang emits a bit
more canonical. More work is needed for vftables, but that isn't a clear
win so I plan to send it for review.
llvm-svn: 220398
diff --git a/clang/test/CodeGenCXX/microsoft-abi-dynamic-cast.cpp b/clang/test/CodeGenCXX/microsoft-abi-dynamic-cast.cpp
index 225407b..f2e9da7 100644
--- a/clang/test/CodeGenCXX/microsoft-abi-dynamic-cast.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-dynamic-cast.cpp
@@ -20,11 +20,10 @@
T* test2(A* x) { return &dynamic_cast<T&>(*x); }
// CHECK-LABEL: define %struct.T* @"\01?test2@@YAPAUT@@PAUA@@@Z"(%struct.A* %x)
// CHECK: [[CAST:%.*]] = bitcast %struct.A* %x to i8*
-// CHECK-NEXT: [[BITCAST:%.*]] = bitcast %struct.A* %x to i8**
-// CHECK-NEXT: [[VBTBL:%.*]] = load i8** [[BITCAST]], align 4
-// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i8* [[VBTBL]], i32 4
-// CHECK-NEXT: [[VBOFFPCAST:%.*]] = bitcast i8* [[VBOFFP]] to i32*
-// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFPCAST]], align 4
+// CHECK-NEXT: [[VBPTRPTR:%.*]] = getelementptr inbounds %struct.A* %x, i32 0, i32 0
+// CHECK-NEXT: [[VBTBL:%.*]] = load i32** [[VBPTRPTR]], align 4
+// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i32* [[VBTBL]], i32 1
+// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFP]], align 4
// CHECK-NEXT: [[ADJ:%.*]] = getelementptr inbounds i8* [[CAST]], i32 [[VBOFFS]]
// CHECK-NEXT: [[CALL:%.*]] = tail call i8* @__RTDynamicCast(i8* [[ADJ]], i32 [[VBOFFS]], i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUA@@@8" to i8*), i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUT@@@8" to i8*), i32 1)
// CHECK-NEXT: [[RET:%.*]] = bitcast i8* [[CALL]] to %struct.T*
@@ -34,11 +33,10 @@
// CHECK-LABEL: define %struct.T* @"\01?test3@@YAPAUT@@PAUB@@@Z"(%struct.B* %x)
// CHECK: [[VOIDP:%.*]] = getelementptr inbounds %struct.B* %x, i32 0, i32 0, i32 0
// CHECK-NEXT: [[VBPTR:%.*]] = getelementptr inbounds i8* [[VOIDP]], i32 4
-// CHECK-NEXT: [[BITCAST:%.*]] = bitcast i8* [[VBPTR:%.*]] to i8**
-// CHECK-NEXT: [[VBTBL:%.*]] = load i8** [[BITCAST]], align 4
-// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i8* [[VBTBL]], i32 4
-// CHECK-NEXT: [[VBOFFPCAST:%.*]] = bitcast i8* [[VBOFFP]] to i32*
-// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFPCAST]], align 4
+// CHECK-NEXT: [[VBPTRPTR:%.*]] = bitcast i8* [[VBPTR:%.*]] to i32**
+// CHECK-NEXT: [[VBTBL:%.*]] = load i32** [[VBPTRPTR]], align 4
+// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i32* [[VBTBL]], i32 1
+// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFP]], align 4
// CHECK-NEXT: [[DELTA:%.*]] = add nsw i32 [[VBOFFS]], 4
// CHECK-NEXT: [[ADJ:%.*]] = getelementptr inbounds i8* [[VOIDP]], i32 [[DELTA]]
// CHECK-NEXT: [[CALL:%.*]] = tail call i8* @__RTDynamicCast(i8* [[ADJ]], i32 [[DELTA]], i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUB@@@8" to i8*), i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUT@@@8" to i8*), i32 1)
@@ -57,11 +55,10 @@
// CHECK: [[CHECK:%.*]] = icmp eq %struct.A* %x, null
// CHECK-NEXT: br i1 [[CHECK]]
// CHECK: [[VOIDP:%.*]] = bitcast %struct.A* %x to i8*
-// CHECK-NEXT: [[BITCAST:%.*]] = bitcast %struct.A* %x to i8**
-// CHECK-NEXT: [[VBTBL:%.*]] = load i8** [[BITCAST]], align 4
-// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i8* [[VBTBL]], i32 4
-// CHECK-NEXT: [[VBOFFPCAST:%.*]] = bitcast i8* [[VBOFFP]] to i32*
-// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFPCAST:%.*]], align 4
+// CHECK-NEXT: [[VBPTRPTR:%.*]] = getelementptr inbounds %struct.A* %x, i32 0, i32 0
+// CHECK-NEXT: [[VBTBL:%.*]] = load i32** [[VBPTRPTR]], align 4
+// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i32* [[VBTBL]], i32 1
+// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFP]], align 4
// CHECK-NEXT: [[ADJ:%.*]] = getelementptr inbounds i8* [[VOIDP]], i32 [[VBOFFS]]
// CHECK-NEXT: [[CALL:%.*]] = tail call i8* @__RTDynamicCast(i8* [[ADJ]], i32 [[VBOFFS]], i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUA@@@8" to i8*), i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUT@@@8" to i8*), i32 0)
// CHECK-NEXT: [[RES:%.*]] = bitcast i8* [[CALL]] to %struct.T*
@@ -75,11 +72,10 @@
// CHECK-NEXT: br i1 [[CHECK]]
// CHECK: [[CAST:%.*]] = getelementptr inbounds %struct.B* %x, i32 0, i32 0, i32 0
// CHECK-NEXT: [[VBPTR:%.*]] = getelementptr inbounds i8* [[CAST]], i32 4
-// CHECK-NEXT: [[BITCAST:%.*]] = bitcast i8* [[VBPTR]] to i8**
-// CHECK-NEXT: [[VBTBL:%.*]] = load i8** [[BITCAST]], align 4
-// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i8* [[VBTBL]], i32 4
-// CHECK-NEXT: [[VBOFFPCAST:%.*]] = bitcast i8* [[VBOFFP]] to i32*
-// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFPCAST:%.*]], align 4
+// CHECK-NEXT: [[VBPTRPTR:%.*]] = bitcast i8* [[VBPTR]] to i32**
+// CHECK-NEXT: [[VBTBL:%.*]] = load i32** [[VBPTRPTR]], align 4
+// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i32* [[VBTBL]], i32 1
+// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFP]], align 4
// CHECK-NEXT: [[DELTA:%.*]] = add nsw i32 [[VBOFFS]], 4
// CHECK-NEXT: [[ADJ:%.*]] = getelementptr inbounds i8* [[CAST]], i32 [[DELTA]]
// CHECK-NEXT: [[CALL:%.*]] = tail call i8* @__RTDynamicCast(i8* [[ADJ]], i32 [[DELTA]], i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUB@@@8" to i8*), i8* bitcast (%rtti.TypeDescriptor7* @"\01??_R0?AUT@@@8" to i8*), i32 0)
@@ -99,11 +95,10 @@
// CHECK: [[CHECK:%.*]] = icmp eq %struct.A* %x, null
// CHECK-NEXT: br i1 [[CHECK]]
// CHECK: [[VOIDP:%.*]] = bitcast %struct.A* %x to i8*
-// CHECK-NEXT: [[BITCAST:%.*]] = bitcast %struct.A* %x to i8**
-// CHECK-NEXT: [[VBTBL:%.*]] = load i8** [[BITCAST]], align 4
-// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i8* [[VBTBL]], i32 4
-// CHECK-NEXT: [[VBOFFPCAST:%.*]] = bitcast i8* [[VBOFFP]] to i32*
-// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFPCAST:%.*]], align 4
+// CHECK-NEXT: [[VBPTRPTR:%.*]] = getelementptr inbounds %struct.A* %x, i32 0, i32 0
+// CHECK-NEXT: [[VBTBL:%.*]] = load i32** [[VBPTRPTR]], align 4
+// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i32* [[VBTBL]], i32 1
+// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFP]], align 4
// CHECK-NEXT: [[ADJ:%.*]] = getelementptr inbounds i8* [[VOIDP]], i32 [[VBOFFS]]
// CHECK-NEXT: [[RES:%.*]] = tail call i8* @__RTCastToVoid(i8* [[ADJ]])
// CHECK-NEXT: br label
@@ -116,11 +111,10 @@
// CHECK-NEXT: br i1 [[CHECK]]
// CHECK: [[CAST:%.*]] = getelementptr inbounds %struct.B* %x, i32 0, i32 0, i32 0
// CHECK-NEXT: [[VBPTR:%.*]] = getelementptr inbounds i8* [[CAST]], i32 4
-// CHECK-NEXT: [[BITCAST:%.*]] = bitcast i8* [[VBPTR]] to i8**
-// CHECK-NEXT: [[VBTBL:%.*]] = load i8** [[BITCAST]], align 4
-// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i8* [[VBTBL]], i32 4
-// CHECK-NEXT: [[VBOFFPCAST:%.*]] = bitcast i8* [[VBOFFP]] to i32*
-// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFPCAST:%.*]], align 4
+// CHECK-NEXT: [[VBPTRPTR:%.*]] = bitcast i8* [[VBPTR]] to i32**
+// CHECK-NEXT: [[VBTBL:%.*]] = load i32** [[VBPTRPTR]], align 4
+// CHECK-NEXT: [[VBOFFP:%.*]] = getelementptr inbounds i32* [[VBTBL]], i32 1
+// CHECK-NEXT: [[VBOFFS:%.*]] = load i32* [[VBOFFP]], align 4
// CHECK-NEXT: [[DELTA:%.*]] = add nsw i32 [[VBOFFS]], 4
// CHECK-NEXT: [[ADJ:%.*]] = getelementptr inbounds i8* [[CAST]], i32 [[DELTA]]
// CHECK-NEXT: [[CALL:%.*]] = tail call i8* @__RTCastToVoid(i8* [[ADJ]])