IR: Type ID summary extensions for WPD; thread summary into WPD pass.

Make the whole thing testable by adding YAML I/O support for the WPD
summary information and adding some negative tests that exercise the
YAML support.

Differential Revision: https://reviews.llvm.org/D29782

llvm-svn: 294981

include/llvm/IR/ModuleSummaryIndex.h

@@ -439,8 +439,40 @@ struct TypeTestResolution {
   unsigned SizeM1BitWidth = 0;
 };
 
+struct WholeProgramDevirtResolution {
+  enum Kind {
+    Indir,      ///< Just do a regular virtual call
+    SingleImpl, ///< Single implementation devirtualization
+  } TheKind = Indir;
+
+  std::string SingleImplName;
+
+  struct ByArg {
+    enum Kind {
+      Indir,            ///< Just do a regular virtual call
+      UniformRetVal,    ///< Uniform return value optimization
+      UniqueRetVal,     ///< Unique return value optimization
+      VirtualConstProp, ///< Virtual constant propagation
+    } TheKind = Indir;
+
+    /// Additional information for the resolution:
+    /// - UniformRetVal: the uniform return value.
+    /// - UniqueRetVal: the return value associated with the unique vtable (0 or
+    ///   1).
+    uint64_t Info = 0;
+  };
+
+  /// Resolutions for calls with all constant integer arguments (excluding the
+  /// first argument, "this"), where the key is the argument vector.
+  std::map<std::vector<uint64_t>, ByArg> ResByArg;
+};
+
 struct TypeIdSummary {
   TypeTestResolution TTRes;
+
+  /// Mapping from byte offset to whole-program devirt resolution for that
+  /// (typeid, byte offset) pair.
+  std::map<uint64_t, WholeProgramDevirtResolution> WPDRes;
 };
 
 /// 160 bits SHA1

include/llvm/IR/ModuleSummaryIndexYAML.h

@@ -33,14 +33,106 @@ template <> struct MappingTraits<TypeTestResolution> {
   }
 };
 
+template <>
+struct ScalarEnumerationTraits<WholeProgramDevirtResolution::ByArg::Kind> {
+  static void enumeration(IO &io,
+                          WholeProgramDevirtResolution::ByArg::Kind &value) {
+    io.enumCase(value, "Indir", WholeProgramDevirtResolution::ByArg::Indir);
+    io.enumCase(value, "UniformRetVal",
+                WholeProgramDevirtResolution::ByArg::UniformRetVal);
+    io.enumCase(value, "UniqueRetVal",
+                WholeProgramDevirtResolution::ByArg::UniqueRetVal);
+    io.enumCase(value, "VirtualConstProp",
+                WholeProgramDevirtResolution::ByArg::VirtualConstProp);
+  }
+};
+
+template <> struct MappingTraits<WholeProgramDevirtResolution::ByArg> {
+  static void mapping(IO &io, WholeProgramDevirtResolution::ByArg &res) {
+    io.mapOptional("Kind", res.TheKind);
+    io.mapOptional("Info", res.Info);
+  }
+};
+
+template <>
+struct CustomMappingTraits<
+    std::map<std::vector<uint64_t>, WholeProgramDevirtResolution::ByArg>> {
+  static void inputOne(
+      IO &io, StringRef Key,
+      std::map<std::vector<uint64_t>, WholeProgramDevirtResolution::ByArg> &V) {
+    std::vector<uint64_t> Args;
+    std::pair<StringRef, StringRef> P = {"", Key};
+    while (!P.second.empty()) {
+      P = P.second.split(',');
+      uint64_t Arg;
+      if (P.first.getAsInteger(0, Arg)) {
+        io.setError("key not an integer");
+        return;
+      }
+      Args.push_back(Arg);
+    }
+    io.mapRequired(Key.str().c_str(), V[Args]);
+  }
+  static void output(
+      IO &io,
+      std::map<std::vector<uint64_t>, WholeProgramDevirtResolution::ByArg> &V) {
+    for (auto &P : V) {
+      std::string Key;
+      for (uint64_t Arg : P.first) {
+        if (!Key.empty())
+          Key += ',';
+        Key += llvm::utostr(Arg);
+      }
+      io.mapRequired(Key.c_str(), P.second);
+    }
+  }
+};
+
+template <> struct ScalarEnumerationTraits<WholeProgramDevirtResolution::Kind> {
+  static void enumeration(IO &io, WholeProgramDevirtResolution::Kind &value) {
+    io.enumCase(value, "Indir", WholeProgramDevirtResolution::Indir);
+    io.enumCase(value, "SingleImpl", WholeProgramDevirtResolution::SingleImpl);
+  }
+};
+
+template <> struct MappingTraits<WholeProgramDevirtResolution> {
+  static void mapping(IO &io, WholeProgramDevirtResolution &res) {
+    io.mapOptional("Kind", res.TheKind);
+    io.mapOptional("SingleImplName", res.SingleImplName);
+    io.mapOptional("ResByArg", res.ResByArg);
+  }
+};
+
+template <>
+struct CustomMappingTraits<std::map<uint64_t, WholeProgramDevirtResolution>> {
+  static void inputOne(IO &io, StringRef Key,
+                       std::map<uint64_t, WholeProgramDevirtResolution> &V) {
+    uint64_t KeyInt;
+    if (Key.getAsInteger(0, KeyInt)) {
+      io.setError("key not an integer");
+      return;
+    }
+    io.mapRequired(Key.str().c_str(), V[KeyInt]);
+  }
+  static void output(IO &io, std::map<uint64_t, WholeProgramDevirtResolution> &V) {
+    for (auto &P : V)
+      io.mapRequired(llvm::utostr(P.first).c_str(), P.second);
+  }
+};
+
 template <> struct MappingTraits<TypeIdSummary> {
   static void mapping(IO &io, TypeIdSummary& summary) {
     io.mapOptional("TTRes", summary.TTRes);
+    io.mapOptional("WPDRes", summary.WPDRes);
   }
 };
 
 struct FunctionSummaryYaml {
   std::vector<uint64_t> TypeTests;
+  std::vector<FunctionSummary::VFuncId> TypeTestAssumeVCalls,
+      TypeCheckedLoadVCalls;
+  std::vector<FunctionSummary::ConstVCall> TypeTestAssumeConstVCalls,
+      TypeCheckedLoadConstVCalls;
 };
 
 } // End yaml namespace
@@ -51,9 +143,38 @@ LLVM_YAML_IS_SEQUENCE_VECTOR(uint64_t)
 namespace llvm {
 namespace yaml {
 
+template <> struct MappingTraits<FunctionSummary::VFuncId> {
+  static void mapping(IO &io, FunctionSummary::VFuncId& id) {
+    io.mapOptional("GUID", id.GUID);
+    io.mapOptional("Offset", id.Offset);
+  }
+};
+
+template <> struct MappingTraits<FunctionSummary::ConstVCall> {
+  static void mapping(IO &io, FunctionSummary::ConstVCall& id) {
+    io.mapOptional("VFunc", id.VFunc);
+    io.mapOptional("Args", id.Args);
+  }
+};
+
+} // End yaml namespace
+} // End llvm namespace
+
+LLVM_YAML_IS_SEQUENCE_VECTOR(FunctionSummary::VFuncId)
+LLVM_YAML_IS_SEQUENCE_VECTOR(FunctionSummary::ConstVCall)
+
+namespace llvm {
+namespace yaml {
+
 template <> struct MappingTraits<FunctionSummaryYaml> {
   static void mapping(IO &io, FunctionSummaryYaml& summary) {
     io.mapOptional("TypeTests", summary.TypeTests);
+    io.mapOptional("TypeTestAssumeVCalls", summary.TypeTestAssumeVCalls);
+    io.mapOptional("TypeCheckedLoadVCalls", summary.TypeCheckedLoadVCalls);
+    io.mapOptional("TypeTestAssumeConstVCalls",
+                   summary.TypeTestAssumeConstVCalls);
+    io.mapOptional("TypeCheckedLoadConstVCalls",
+                   summary.TypeCheckedLoadConstVCalls);
   }
 };
 
@@ -83,10 +204,10 @@ template <> struct CustomMappingTraits<GlobalValueSummaryMapTy> {
       Elem.push_back(llvm::make_unique<FunctionSummary>(
           GVFlags, 0, ArrayRef<ValueInfo>{},
           ArrayRef<FunctionSummary::EdgeTy>{}, std::move(FSum.TypeTests),
-          ArrayRef<FunctionSummary::VFuncId>{},
-          ArrayRef<FunctionSummary::VFuncId>{},
-          ArrayRef<FunctionSummary::ConstVCall>{},
-          ArrayRef<FunctionSummary::ConstVCall>{}));
+          std::move(FSum.TypeTestAssumeVCalls),
+          std::move(FSum.TypeCheckedLoadVCalls),
+          std::move(FSum.TypeTestAssumeConstVCalls),
+          std::move(FSum.TypeCheckedLoadConstVCalls)));
     }
   }
   static void output(IO &io, GlobalValueSummaryMapTy &V) {
@@ -94,7 +215,11 @@ template <> struct CustomMappingTraits<GlobalValueSummaryMapTy> {
       std::vector<FunctionSummaryYaml> FSums;
       for (auto &Sum : P.second) {
         if (auto *FSum = dyn_cast<FunctionSummary>(Sum.get()))
-          FSums.push_back(FunctionSummaryYaml{FSum->type_tests()});
+          FSums.push_back(FunctionSummaryYaml{
+              FSum->type_tests(), FSum->type_test_assume_vcalls(),
+              FSum->type_checked_load_vcalls(),
+              FSum->type_test_assume_const_vcalls(),
+              FSum->type_checked_load_const_vcalls()});
       }
       if (!FSums.empty())
         io.mapRequired(llvm::utostr(P.first).c_str(), FSums);

include/llvm/Transforms/IPO.h

@@ -235,7 +235,8 @@ ModulePass *createCrossDSOCFIPass();
 
 /// \brief This pass implements whole-program devirtualization using type
 /// metadata.
-ModulePass *createWholeProgramDevirtPass();
+ModulePass *createWholeProgramDevirtPass(PassSummaryAction Action,
+                                         ModuleSummaryIndex *Index);
 
 /// This pass splits globals into pieces for the benefit of whole-program
 /// devirtualization and control-flow integrity.

lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -700,7 +700,8 @@ void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) {
   PM.add(createGlobalSplitPass());
 
   // Apply whole-program devirtualization and virtual constant propagation.
-  PM.add(createWholeProgramDevirtPass());
+  PM.add(createWholeProgramDevirtPass(
+      Summary ? PassSummaryAction::Export : PassSummaryAction::None, Summary));
 
   // That's all we need at opt level 1.
   if (OptLevel == 1)

lib/Transforms/IPO/WholeProgramDevirt.cpp

@@ -54,10 +54,13 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/ModuleSummaryIndexYAML.h"
 #include "llvm/Pass.h"
 #include "llvm/PassRegistry.h"
 #include "llvm/PassSupport.h"
 #include "llvm/Support/Casting.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/Utils/Evaluator.h"
@@ -72,6 +75,26 @@ using namespace wholeprogramdevirt;
 
 #define DEBUG_TYPE "wholeprogramdevirt"
 
+static cl::opt<PassSummaryAction> ClSummaryAction(
+    "wholeprogramdevirt-summary-action",
+    cl::desc("What to do with the summary when running this pass"),
+    cl::values(clEnumValN(PassSummaryAction::None, "none", "Do nothing"),
+               clEnumValN(PassSummaryAction::Import, "import",
+                          "Import typeid resolutions from summary and globals"),
+               clEnumValN(PassSummaryAction::Export, "export",
+                          "Export typeid resolutions to summary and globals")),
+    cl::Hidden);
+
+static cl::opt<std::string> ClReadSummary(
+    "wholeprogramdevirt-read-summary",
+    cl::desc("Read summary from given YAML file before running pass"),
+    cl::Hidden);
+
+static cl::opt<std::string> ClWriteSummary(
+    "wholeprogramdevirt-write-summary",
+    cl::desc("Write summary to given YAML file after running pass"),
+    cl::Hidden);
+
 // Find the minimum offset that we may store a value of size Size bits at. If
 // IsAfter is set, look for an offset before the object, otherwise look for an
 // offset after the object.
@@ -261,6 +284,10 @@ struct VirtualCallSite {
 
 struct DevirtModule {
   Module &M;
+
+  PassSummaryAction Action;
+  ModuleSummaryIndex *Summary;
+
   IntegerType *Int8Ty;
   PointerType *Int8PtrTy;
   IntegerType *Int32Ty;
@@ -279,8 +306,9 @@ struct DevirtModule {
   // true.
   std::map<CallInst *, unsigned> NumUnsafeUsesForTypeTest;
 
-  DevirtModule(Module &M)
-      : M(M), Int8Ty(Type::getInt8Ty(M.getContext())),
+  DevirtModule(Module &M, PassSummaryAction Action, ModuleSummaryIndex *Summary)
+      : M(M), Action(Action), Summary(Summary),
+        Int8Ty(Type::getInt8Ty(M.getContext())),
         Int8PtrTy(Type::getInt8PtrTy(M.getContext())),
         Int32Ty(Type::getInt32Ty(M.getContext())),
         RemarksEnabled(areRemarksEnabled()) {}
@@ -315,20 +343,35 @@ struct DevirtModule {
   void rebuildGlobal(VTableBits &B);
 
   bool run();
+
+  // Lower the module using the action and summary passed as command line
+  // arguments. For testing purposes only.
+  static bool runForTesting(Module &M);
 };
 
 struct WholeProgramDevirt : public ModulePass {
   static char ID;
 
-  WholeProgramDevirt() : ModulePass(ID) {
+  bool UseCommandLine = false;
+
+  PassSummaryAction Action;
+  ModuleSummaryIndex *Summary;
+
+  WholeProgramDevirt() : ModulePass(ID), UseCommandLine(true) {
+    initializeWholeProgramDevirtPass(*PassRegistry::getPassRegistry());
+  }
+
+  WholeProgramDevirt(PassSummaryAction Action, ModuleSummaryIndex *Summary)
+      : ModulePass(ID), Action(Action), Summary(Summary) {
     initializeWholeProgramDevirtPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnModule(Module &M) override {
     if (skipModule(M))
       return false;
-
-    return DevirtModule(M).run();
+    if (UseCommandLine)
+      return DevirtModule::runForTesting(M);
+    return DevirtModule(M, Action, Summary).run();
   }
 };
 
@@ -338,17 +381,50 @@ INITIALIZE_PASS(WholeProgramDevirt, "wholeprogramdevirt",
                 "Whole program devirtualization", false, false)
 char WholeProgramDevirt::ID = 0;
 
-ModulePass *llvm::createWholeProgramDevirtPass() {
-  return new WholeProgramDevirt;
+ModulePass *llvm::createWholeProgramDevirtPass(PassSummaryAction Action,
+                                               ModuleSummaryIndex *Summary) {
+  return new WholeProgramDevirt(Action, Summary);
 }
 
 PreservedAnalyses WholeProgramDevirtPass::run(Module &M,
                                               ModuleAnalysisManager &) {
-  if (!DevirtModule(M).run())
+  if (!DevirtModule(M, PassSummaryAction::None, nullptr).run())
     return PreservedAnalyses::all();
   return PreservedAnalyses::none();
 }
 
+bool DevirtModule::runForTesting(Module &M) {
+  ModuleSummaryIndex Summary;
+
+  // Handle the command-line summary arguments. This code is for testing
+  // purposes only, so we handle errors directly.
+  if (!ClReadSummary.empty()) {
+    ExitOnError ExitOnErr("-wholeprogramdevirt-read-summary: " + ClReadSummary +
+                          ": ");
+    auto ReadSummaryFile =
+        ExitOnErr(errorOrToExpected(MemoryBuffer::getFile(ClReadSummary)));
+
+    yaml::Input In(ReadSummaryFile->getBuffer());
+    In >> Summary;
+    ExitOnErr(errorCodeToError(In.error()));
+  }
+
+  bool Changed = DevirtModule(M, ClSummaryAction, &Summary).run();
+
+  if (!ClWriteSummary.empty()) {
+    ExitOnError ExitOnErr(
+        "-wholeprogramdevirt-write-summary: " + ClWriteSummary + ": ");
+    std::error_code EC;
+    raw_fd_ostream OS(ClWriteSummary, EC, sys::fs::F_Text);
+    ExitOnErr(errorCodeToError(EC));
+
+    yaml::Output Out(OS);
+    Out << Summary;
+  }
+
+  return Changed;
+}
+
 void DevirtModule::buildTypeIdentifierMap(
     std::vector<VTableBits> &Bits,
     DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap) {

test/Transforms/LowerTypeTests/export-allones.ll

@@ -153,7 +153,9 @@
 ; SUMMARY-NEXT:     TTRes:
 ; SUMMARY-NEXT:       Kind:            AllOnes
 ; SUMMARY-NEXT:       SizeM1BitWidth:  7
+; SUMMARY-NEXT:     WPDRes:
 ; SUMMARY-NEXT:   typeid2:
 ; SUMMARY-NEXT:     TTRes:
 ; SUMMARY-NEXT:       Kind:            AllOnes
 ; SUMMARY-NEXT:       SizeM1BitWidth:  32
+; SUMMARY-NEXT:     WPDRes:

test/Transforms/LowerTypeTests/export-bytearray.ll

@@ -32,7 +32,9 @@
 ; SUMMARY-NEXT:     TTRes:
 ; SUMMARY-NEXT:       Kind:            ByteArray
 ; SUMMARY-NEXT:       SizeM1BitWidth:  7
+; SUMMARY-NEXT:     WPDRes:
 ; SUMMARY-NEXT:   typeid2:
 ; SUMMARY-NEXT:     TTRes:
 ; SUMMARY-NEXT:       Kind:            ByteArray
 ; SUMMARY-NEXT:       SizeM1BitWidth:  32
+; SUMMARY-NEXT:     WPDRes:

test/Transforms/LowerTypeTests/export-inline.ll

@@ -27,7 +27,9 @@
 ; SUMMARY-NEXT:     TTRes:
 ; SUMMARY-NEXT:       Kind:            Inline
 ; SUMMARY-NEXT:       SizeM1BitWidth:  5
+; SUMMARY-NEXT:     WPDRes:
 ; SUMMARY-NEXT:   typeid2:
 ; SUMMARY-NEXT:     TTRes:
 ; SUMMARY-NEXT:       Kind:            Inline
 ; SUMMARY-NEXT:       SizeM1BitWidth:  6
+; SUMMARY-NEXT:     WPDRes:

test/Transforms/WholeProgramDevirt/Inputs/import-indir.yaml

@@ -0,0 +1,41 @@
+---
+GlobalValueMap:
+  42:
+    - TypeTestAssumeVCalls:
+        - GUID: 123
+          Offset: 0
+        - GUID: 456
+          Offset: 4
+      TypeCheckedLoadVCalls:
+        - GUID: 789
+          Offset: 8
+        - GUID: 1234
+          Offset: 16
+      TypeTestAssumeConstVCalls:
+        - VFunc:
+            GUID: 123
+            Offset: 4
+          Args: [12, 24]
+      TypeCheckedLoadConstVCalls:
+        - VFunc:
+            GUID: 456
+            Offset: 8
+          Args: [24, 12]
+TypeIdMap:
+  typeid1:
+    WPDRes:
+      0:
+        Kind: Indir
+      4:
+        Kind: Indir
+        ResByArg:
+          "":
+            Kind: UniformRetVal
+            Info: 12
+          12:
+            Kind: UniformRetVal
+            Info: 24
+          "12,24":
+            Kind: UniformRetVal
+            Info: 48
+...

test/Transforms/WholeProgramDevirt/export-nothing.ll

@@ -0,0 +1,7 @@
+; RUN: opt -wholeprogramdevirt -wholeprogramdevirt-summary-action=export -wholeprogramdevirt-write-summary=%t -o /dev/null %s
+; RUN: FileCheck %s < %t
+
+; CHECK: ---
+; CHECK-NEXT: GlobalValueMap:
+; CHECK-NEXT: TypeIdMap:
+; CHECK-NEXT: ...

test/Transforms/WholeProgramDevirt/import-indir.ll

@@ -0,0 +1,99 @@
+; Test that we correctly import an indir resolution for type identifier "typeid1".
+; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import -wholeprogramdevirt-read-summary=%S/Inputs/import-indir.yaml -wholeprogramdevirt-write-summary=%t < %s | FileCheck %s
+; RUN: FileCheck --check-prefix=SUMMARY %s < %t
+
+; SUMMARY:     GlobalValueMap:
+; SUMMARY-NEXT:  42:
+; SUMMARY-NEXT:    - TypeTests:
+; SUMMARY-NEXT:      TypeTestAssumeVCalls:
+; SUMMARY-NEXT:        - GUID:            123
+; SUMMARY-NEXT:          Offset:          0
+; SUMMARY-NEXT:        - GUID:            456
+; SUMMARY-NEXT:          Offset:          4
+; SUMMARY-NEXT:      TypeCheckedLoadVCalls:
+; SUMMARY-NEXT:        - GUID:            789
+; SUMMARY-NEXT:          Offset:          8
+; SUMMARY-NEXT:        - GUID:            1234
+; SUMMARY-NEXT:          Offset:          16
+; SUMMARY-NEXT:      TypeTestAssumeConstVCalls:
+; SUMMARY-NEXT:        - VFunc:
+; SUMMARY-NEXT:            GUID:            123
+; SUMMARY-NEXT:            Offset:          4
+; SUMMARY-NEXT:          Args:
+; SUMMARY-NEXT:            - 12
+; SUMMARY-NEXT:            - 24
+; SUMMARY-NEXT:      TypeCheckedLoadConstVCalls:
+; SUMMARY-NEXT:        - VFunc:
+; SUMMARY-NEXT:            GUID:            456
+; SUMMARY-NEXT:            Offset:          8
+; SUMMARY-NEXT:          Args:
+; SUMMARY-NEXT:            - 24
+; SUMMARY-NEXT:            - 12
+; SUMMARY-NEXT: TypeIdMap:
+; SUMMARY-NEXT:   typeid1:
+; SUMMARY-NEXT:     TTRes:
+; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       SizeM1BitWidth:  0
+; SUMMARY-NEXT:     WPDRes:
+; SUMMARY-NEXT:       0:
+; SUMMARY-NEXT:         Kind:            Indir
+; SUMMARY-NEXT:         SingleImplName:  ''
+; SUMMARY-NEXT:         ResByArg:
+; SUMMARY-NEXT:       4:
+; SUMMARY-NEXT:         Kind:            Indir
+; SUMMARY-NEXT:         SingleImplName:  ''
+; SUMMARY-NEXT:         ResByArg:
+; SUMMARY-NEXT:           :
+; SUMMARY-NEXT:             Kind:            UniformRetVal
+; SUMMARY-NEXT:             Info:            12
+; SUMMARY-NEXT:           12:
+; SUMMARY-NEXT:             Kind:            UniformRetVal
+; SUMMARY-NEXT:             Info:            24
+; SUMMARY-NEXT:           12,24:
+; SUMMARY-NEXT:             Kind:            UniformRetVal
+; SUMMARY-NEXT:             Info:            48
+
+target datalayout = "e-p:32:32"
+
+declare void @llvm.assume(i1)
+declare void @llvm.trap()
+declare {i8*, i1} @llvm.type.checked.load(i8*, i32, metadata)
+declare i1 @llvm.type.test(i8*, metadata)
+
+; CHECK: define i1 @f1
+define i1 @f1(i8* %obj) {
+  %vtableptr = bitcast i8* %obj to [1 x i8*]**
+  %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
+  %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
+  %p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid1")
+  call void @llvm.assume(i1 %p)
+  %fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
+  %fptr = load i8*, i8** %fptrptr
+  %fptr_casted = bitcast i8* %fptr to i1 (i8*, i32)*
+  ; CHECK: call i1 %
+  %result = call i1 %fptr_casted(i8* %obj, i32 5)
+  ret i1 %result
+}
+
+; CHECK: define i1 @f2
+define i1 @f2(i8* %obj) {
+  %vtableptr = bitcast i8* %obj to [1 x i8*]**
+  %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
+  %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
+  %pair = call {i8*, i1} @llvm.type.checked.load(i8* %vtablei8, i32 4, metadata !"typeid1")
+  %fptr = extractvalue {i8*, i1} %pair, 0
+  %p = extractvalue {i8*, i1} %pair, 1
+  ; CHECK: [[P:%.*]] = call i1 @llvm.type.test
+  ; CHECK: br i1 [[P]]
+  br i1 %p, label %cont, label %trap
+
+cont:
+  %fptr_casted = bitcast i8* %fptr to i1 (i8*, i32)*
+  ; CHECK: call i1 %
+  %result = call i1 %fptr_casted(i8* %obj, i32 undef)
+  ret i1 %result
+
+trap:
+  call void @llvm.trap()
+  unreachable
+}