Restore "[WPD/LowerTypeTests] Delay lowering/removal of type tests until after ICP"

This restores commit 80d0a137a5, and the
follow on fix in 873c0d0786, with a new
fix for test failures after a 2-stage clang bootstrap, and a more robust
fix for the Chromium build failure that an earlier version partially
fixed. See also discussion on D75201.

Reviewers: evgeny777

Subscribers: mehdi_amini, Prazek, hiraditya, steven_wu, dexonsmith, arphaman, davidxl, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73242

llvm/include/llvm/IR/ModuleSummaryIndex.h

@@ -894,7 +894,8 @@ struct TypeTestResolution {
     Single,    ///< Single element (last example in "Short Inline Bit Vectors")
     AllOnes,   ///< All-ones bit vector ("Eliminating Bit Vector Checks for
                ///  All-Ones Bit Vectors")
-  } TheKind = Unsat;
+    Unknown,   ///< Unknown (analysis not performed, don't lower)
+  } TheKind = Unknown;
 
   /// Range of size-1 expressed as a bit width. For example, if the size is in
   /// range [1,256], this number will be 8. This helps generate the most compact
@@ -1092,7 +1093,7 @@ public:
   // in the way some record are interpreted, like flags for instance.
   // Note that incrementing this may require changes in both BitcodeReader.cpp
   // and BitcodeWriter.cpp.
-  static constexpr uint64_t BitcodeSummaryVersion = 8;
+  static constexpr uint64_t BitcodeSummaryVersion = 9;
 
   // Regular LTO module name for ASM writer
   static constexpr const char *getRegularLTOModuleName() {

llvm/include/llvm/IR/ModuleSummaryIndexYAML.h

@@ -17,6 +17,7 @@ namespace yaml {
 
 template <> struct ScalarEnumerationTraits<TypeTestResolution::Kind> {
   static void enumeration(IO &io, TypeTestResolution::Kind &value) {
+    io.enumCase(value, "Unknown", TypeTestResolution::Unknown);
     io.enumCase(value, "Unsat", TypeTestResolution::Unsat);
     io.enumCase(value, "ByteArray", TypeTestResolution::ByteArray);
     io.enumCase(value, "Inline", TypeTestResolution::Inline);

llvm/lib/AsmParser/LLParser.cpp

@@ -7799,6 +7799,9 @@ bool LLParser::ParseTypeTestResolution(TypeTestResolution &TTRes) {
     return true;
 
   switch (Lex.getKind()) {
+  case lltok::kw_unknown:
+    TTRes.TheKind = TypeTestResolution::Unknown;
+    break;
   case lltok::kw_unsat:
     TTRes.TheKind = TypeTestResolution::Unsat;
     break;

llvm/lib/IR/AsmWriter.cpp

@@ -2861,6 +2861,8 @@ static const char *getWholeProgDevirtResByArgKindName(
 
 static const char *getTTResKindName(TypeTestResolution::Kind K) {
   switch (K) {
+  case TypeTestResolution::Unknown:
+    return "unknown";
   case TypeTestResolution::Unsat:
     return "unsat";
   case TypeTestResolution::ByteArray:

llvm/lib/Passes/PassBuilder.cpp

@@ -971,6 +971,12 @@ ModulePassManager PassBuilder::buildModuleSimplificationPipeline(
   if (AttributorRun & AttributorRunOption::MODULE)
     MPM.addPass(AttributorPass());
 
+  // Lower type metadata and the type.test intrinsic in the ThinLTO
+  // post link pipeline after ICP. This is to enable usage of the type
+  // tests in ICP sequences.
+  if (Phase == ThinLTOPhase::PostLink)
+    MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
+
   // Interprocedural constant propagation now that basic cleanup has occurred
   // and prior to optimizing globals.
   // FIXME: This position in the pipeline hasn't been carefully considered in
@@ -1355,6 +1361,9 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level, bool DebugLogging,
     // metadata and intrinsics.
     MPM.addPass(WholeProgramDevirtPass(ExportSummary, nullptr));
     MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
+    // Run a second time to clean up any type tests left behind by WPD for use
+    // in ICP.
+    MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
     return MPM;
   }
 
@@ -1421,6 +1430,10 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level, bool DebugLogging,
     // The LowerTypeTestsPass needs to run to lower type metadata and the
     // type.test intrinsics. The pass does nothing if CFI is disabled.
     MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
+    // Run a second time to clean up any type tests left behind by WPD for use
+    // in ICP (which is performed earlier than this in the regular LTO
+    // pipeline).
+    MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
     return MPM;
   }
 
@@ -1548,6 +1561,9 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level, bool DebugLogging,
   // to be run at link time if CFI is enabled. This pass does nothing if
   // CFI is disabled.
   MPM.addPass(LowerTypeTestsPass(ExportSummary, nullptr));
+  // Run a second time to clean up any type tests left behind by WPD for use
+  // in ICP (which is performed earlier than this in the regular LTO pipeline).
+  MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true));
 
   // Enable splitting late in the FullLTO post-link pipeline. This is done in
   // the same stage in the old pass manager (\ref addLateLTOOptimizationPasses).

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

@@ -735,6 +735,9 @@ static bool isKnownTypeIdMember(Metadata *TypeId, const DataLayout &DL,
 /// replace the call with.
 Value *LowerTypeTestsModule::lowerTypeTestCall(Metadata *TypeId, CallInst *CI,
                                                const TypeIdLowering &TIL) {
+  // Delay lowering if the resolution is currently unknown.
+  if (TIL.TheKind == TypeTestResolution::Unknown)
+    return nullptr;
   if (TIL.TheKind == TypeTestResolution::Unsat)
     return ConstantInt::getFalse(M.getContext());
 
@@ -1036,15 +1039,19 @@ void LowerTypeTestsModule::importTypeTest(CallInst *CI) {
     report_fatal_error("Second argument of llvm.type.test must be metadata");
 
   auto TypeIdStr = dyn_cast<MDString>(TypeIdMDVal->getMetadata());
+  // If this is a local unpromoted type, which doesn't have a metadata string,
+  // treat as Unknown and delay lowering, so that we can still utilize it for
+  // later optimizations.
   if (!TypeIdStr)
-    report_fatal_error(
+    return;
-        "Second argument of llvm.type.test must be a metadata string");
 
   TypeIdLowering TIL = importTypeId(TypeIdStr->getString());
   Value *Lowered = lowerTypeTestCall(TypeIdStr, CI, TIL);
+  if (Lowered) {
     CI->replaceAllUsesWith(Lowered);
     CI->eraseFromParent();
   }
+}
 
 // ThinLTO backend: the function F has a jump table entry; update this module
 // accordingly. isJumpTableCanonical describes the type of the jump table entry.
@@ -1166,11 +1173,13 @@ void LowerTypeTestsModule::lowerTypeTestCalls(
     for (CallInst *CI : TIUI.CallSites) {
       ++NumTypeTestCallsLowered;
       Value *Lowered = lowerTypeTestCall(TypeId, CI, TIL);
+      if (Lowered) {
         CI->replaceAllUsesWith(Lowered);
         CI->eraseFromParent();
       }
     }
   }
+}
 
 void LowerTypeTestsModule::verifyTypeMDNode(GlobalObject *GO, MDNode *Type) {
   if (Type->getNumOperands() != 2)

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -515,6 +515,7 @@ void PassManagerBuilder::populateModulePassManager(
       MPM.add(createBarrierNoopPass());
 
     if (PerformThinLTO) {
+      MPM.add(createLowerTypeTestsPass(nullptr, nullptr, true));
       // Drop available_externally and unreferenced globals. This is necessary
       // with ThinLTO in order to avoid leaving undefined references to dead
       // globals in the object file.
@@ -548,9 +549,11 @@ void PassManagerBuilder::populateModulePassManager(
   // inter-module indirect calls. For that we perform indirect call promotion
   // earlier in the pass pipeline, here before globalopt. Otherwise imported
   // available_externally functions look unreferenced and are removed.
-  if (PerformThinLTO)
+  if (PerformThinLTO) {
     MPM.add(createPGOIndirectCallPromotionLegacyPass(/*InLTO = */ true,
                                                      !PGOSampleUse.empty()));
+    MPM.add(createLowerTypeTestsPass(nullptr, nullptr, true));
+  }
 
   // For SamplePGO in ThinLTO compile phase, we do not want to unroll loops
   // as it will change the CFG too much to make the 2nd profile annotation
@@ -1079,8 +1082,8 @@ void PassManagerBuilder::populateThinLTOPassManager(
     PM.add(createVerifierPass());
 
   if (ImportSummary) {
-    // These passes import type identifier resolutions for whole-program
+    // This pass imports type identifier resolutions for whole-program
-    // devirtualization and CFI. They must run early because other passes may
+    // devirtualization and CFI. It must run early because other passes may
     // disturb the specific instruction patterns that these passes look for,
     // creating dependencies on resolutions that may not appear in the summary.
     //
@@ -1128,6 +1131,9 @@ void PassManagerBuilder::populateLTOPassManager(legacy::PassManagerBase &PM) {
   // control flow integrity mechanisms (-fsanitize=cfi*) and needs to run at
   // link time if CFI is enabled. The pass does nothing if CFI is disabled.
   PM.add(createLowerTypeTestsPass(ExportSummary, nullptr));
+  // Run a second time to clean up any type tests left behind by WPD for use
+  // in ICP (which is performed earlier than this in the regular LTO pipeline).
+  PM.add(createLowerTypeTestsPass(nullptr, nullptr, true));
 
   if (OptLevel != 0)
     addLateLTOOptimizationPasses(PM);

llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp

@@ -540,7 +540,9 @@ struct DevirtModule {
 
   bool areRemarksEnabled();
 
-  void scanTypeTestUsers(Function *TypeTestFunc);
+  void
+  scanTypeTestUsers(Function *TypeTestFunc,
+                    DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap);
   void scanTypeCheckedLoadUsers(Function *TypeCheckedLoadFunc);
 
   void buildTypeIdentifierMap(
@@ -1705,7 +1707,9 @@ bool DevirtModule::areRemarksEnabled() {
   return false;
 }
 
-void DevirtModule::scanTypeTestUsers(Function *TypeTestFunc) {
+void DevirtModule::scanTypeTestUsers(
+    Function *TypeTestFunc,
+    DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap) {
   // Find all virtual calls via a virtual table pointer %p under an assumption
   // of the form llvm.assume(llvm.type.test(%p, %md)). This indicates that %p
   // points to a member of the type identifier %md. Group calls by (type ID,
@@ -1724,15 +1728,16 @@ void DevirtModule::scanTypeTestUsers(Function *TypeTestFunc) {
     auto &DT = LookupDomTree(*CI->getFunction());
     findDevirtualizableCallsForTypeTest(DevirtCalls, Assumes, CI, DT);
 
-    // If we found any, add them to CallSlots.
-    if (!Assumes.empty()) {
     Metadata *TypeId =
         cast<MetadataAsValue>(CI->getArgOperand(1))->getMetadata();
+    // If we found any, add them to CallSlots.
+    if (!Assumes.empty()) {
       Value *Ptr = CI->getArgOperand(0)->stripPointerCasts();
       for (DevirtCallSite Call : DevirtCalls)
         CallSlots[{TypeId, Call.Offset}].addCallSite(Ptr, Call.CB, nullptr);
     }
 
+    auto RemoveTypeTestAssumes = [&]() {
       // We no longer need the assumes or the type test.
       for (auto Assume : Assumes)
         Assume->eraseFromParent();
@@ -1740,6 +1745,42 @@ void DevirtModule::scanTypeTestUsers(Function *TypeTestFunc) {
       // may use the vtable argument later.
       if (CI->use_empty())
         CI->eraseFromParent();
+    };
+
+    // At this point we could remove all type test assume sequences, as they
+    // were originally inserted for WPD. However, we can keep these in the
+    // code stream for later analysis (e.g. to help drive more efficient ICP
+    // sequences). They will eventually be removed by a second LowerTypeTests
+    // invocation that cleans them up. In order to do this correctly, the first
+    // LowerTypeTests invocation needs to know that they have "Unknown" type
+    // test resolution, so that they aren't treated as Unsat and lowered to
+    // False, which will break any uses on assumes. Below we remove any type
+    // test assumes that will not be treated as Unknown by LTT.
+
+    // The type test assumes will be treated by LTT as Unsat if the type id is
+    // not used on a global (in which case it has no entry in the TypeIdMap).
+    if (!TypeIdMap.count(TypeId))
+      RemoveTypeTestAssumes();
+
+    // For ThinLTO importing, we need to remove the type test assumes if this is
+    // an MDString type id without a corresponding TypeIdSummary. Any
+    // non-MDString type ids are ignored and treated as Unknown by LTT, so their
+    // type test assumes can be kept. If the MDString type id is missing a
+    // TypeIdSummary (e.g. because there was no use on a vcall, preventing the
+    // exporting phase of WPD from analyzing it), then it would be treated as
+    // Unsat by LTT and we need to remove its type test assumes here. If not
+    // used on a vcall we don't need them for later optimization use in any
+    // case.
+    else if (ImportSummary && isa<MDString>(TypeId)) {
+      const TypeIdSummary *TidSummary =
+          ImportSummary->getTypeIdSummary(cast<MDString>(TypeId)->getString());
+      if (!TidSummary)
+        RemoveTypeTestAssumes();
+      else
+        // If one was created it should not be Unsat, because if we reached here
+        // the type id was used on a global.
+        assert(TidSummary->TTRes.TheKind != TypeTestResolution::Unsat);
+    }
   }
 }
 
@@ -1931,8 +1972,13 @@ bool DevirtModule::run() {
       (!TypeCheckedLoadFunc || TypeCheckedLoadFunc->use_empty()))
     return false;
 
+  // Rebuild type metadata into a map for easy lookup.
+  std::vector<VTableBits> Bits;
+  DenseMap<Metadata *, std::set<TypeMemberInfo>> TypeIdMap;
+  buildTypeIdentifierMap(Bits, TypeIdMap);
+
   if (TypeTestFunc && AssumeFunc)
-    scanTypeTestUsers(TypeTestFunc);
+    scanTypeTestUsers(TypeTestFunc, TypeIdMap);
 
   if (TypeCheckedLoadFunc)
     scanTypeCheckedLoadUsers(TypeCheckedLoadFunc);
@@ -1954,10 +2000,6 @@ bool DevirtModule::run() {
     return true;
   }
 
-  // Rebuild type metadata into a map for easy lookup.
-  std::vector<VTableBits> Bits;
-  DenseMap<Metadata *, std::set<TypeMemberInfo>> TypeIdMap;
-  buildTypeIdentifierMap(Bits, TypeIdMap);
   if (TypeIdMap.empty())
     return true;
 
@@ -2014,14 +2056,22 @@ bool DevirtModule::run() {
     // function implementation at offset S.first.ByteOffset, and add to
     // TargetsForSlot.
     std::vector<VirtualCallTarget> TargetsForSlot;
-    if (tryFindVirtualCallTargets(TargetsForSlot, TypeIdMap[S.first.TypeID],
-                                  S.first.ByteOffset)) {
     WholeProgramDevirtResolution *Res = nullptr;
-      if (ExportSummary && isa<MDString>(S.first.TypeID))
+    const std::set<TypeMemberInfo> &TypeMemberInfos = TypeIdMap[S.first.TypeID];
+    if (ExportSummary && isa<MDString>(S.first.TypeID) &&
+        TypeMemberInfos.size())
+      // For any type id used on a global's type metadata, create the type id
+      // summary resolution regardless of whether we can devirtualize, so that
+      // lower type tests knows the type id is not Unsat. If it was not used on
+      // a global's type metadata, the TypeIdMap entry set will be empty, and
+      // we don't want to create an entry (with the default Unknown type
+      // resolution), which can prevent detection of the Unsat.
       Res = &ExportSummary
                  ->getOrInsertTypeIdSummary(
                      cast<MDString>(S.first.TypeID)->getString())
                  .WPDRes[S.first.ByteOffset];
+    if (tryFindVirtualCallTargets(TargetsForSlot, TypeMemberInfos,
+                                  S.first.ByteOffset)) {
 
       if (!trySingleImplDevirt(ExportSummary, TargetsForSlot, S.second, Res)) {
         DidVirtualConstProp |=
@@ -2135,11 +2185,14 @@ void DevirtIndex::run() {
     std::vector<ValueInfo> TargetsForSlot;
     auto TidSummary = ExportSummary.getTypeIdCompatibleVtableSummary(S.first.TypeID);
     assert(TidSummary);
-    if (tryFindVirtualCallTargets(TargetsForSlot, *TidSummary,
+    // Create the type id summary resolution regardlness of whether we can
-                                  S.first.ByteOffset)) {
+    // devirtualize, so that lower type tests knows the type id is used on
+    // a global and not Unsat.
     WholeProgramDevirtResolution *Res =
         &ExportSummary.getOrInsertTypeIdSummary(S.first.TypeID)
              .WPDRes[S.first.ByteOffset];
+    if (tryFindVirtualCallTargets(TargetsForSlot, *TidSummary,
+                                  S.first.ByteOffset)) {
 
       if (!trySingleImplDevirt(TargetsForSlot, S.first, S.second, Res,
                                DevirtTargets))

llvm/test/Bitcode/summary_version.ll

@@ -2,7 +2,7 @@
 ; RUN: opt  -module-summary  %s -o - | llvm-bcanalyzer -dump | FileCheck %s
 
 ; CHECK: <GLOBALVAL_SUMMARY_BLOCK
-; CHECK: <VERSION op0=8/>
+; CHECK: <VERSION op0=9/>
 
 
 

llvm/test/Other/new-pm-lto-defaults.ll

@@ -99,6 +99,7 @@
 ; CHECK-O2-NEXT: Running analysis: DemandedBitsAnalysis
 ; CHECK-O2-NEXT: Running pass: CrossDSOCFIPass
 ; CHECK-O2-NEXT: Running pass: LowerTypeTestsPass
+; CHECK-O-NEXT: Running pass: LowerTypeTestsPass
 ; CHECK-O2-NEXT: Running pass: ModuleToFunctionPassAdaptor<{{.*}}SimplifyCFGPass>
 ; CHECK-O2-NEXT: Running pass: EliminateAvailableExternallyPass
 ; CHECK-O2-NEXT: Running pass: GlobalDCEPass

llvm/test/Other/new-pm-thinlto-defaults.ll

@@ -79,6 +79,7 @@
 ; CHECK-O-NEXT: Running pass: LowerExpectIntrinsicPass
 ; CHECK-O3-NEXT: Running pass: CallSiteSplittingPass
 ; CHECK-O-NEXT: Finished llvm::Function pass manager run.
+; CHECK-POSTLINK-O-NEXT: Running pass: LowerTypeTestsPass
 ; CHECK-O-NEXT: Running pass: IPSCCPPass
 ; CHECK-O-NEXT: Running pass: CalledValuePropagationPass
 ; CHECK-O-NEXT: Running pass: GlobalOptPass

llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll

@@ -48,6 +48,7 @@
 ; CHECK-O-NEXT: Running pass: LowerExpectIntrinsicPass
 ; CHECK-O3-NEXT: Running pass: CallSiteSplittingPass
 ; CHECK-O-NEXT: Finished {{.*}}Function pass manager run.
+; CHECK-O-NEXT: Running pass: LowerTypeTestsPass
 ; CHECK-O-NEXT: Running pass: IPSCCPPass
 ; CHECK-O-NEXT: Running pass: CalledValuePropagationPass
 ; CHECK-O-NEXT: Running pass: GlobalOptPass

llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll

@@ -59,6 +59,7 @@
 ; CHECK-O-NEXT: Running analysis: CallGraphAnalysis
 ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running pass: PGOIndirectCallPromotion
+; CHECK-O-NEXT: Running pass: LowerTypeTestsPass
 ; CHECK-O-NEXT: Running pass: IPSCCPPass
 ; CHECK-O-NEXT: Running pass: CalledValuePropagationPass
 ; CHECK-O-NEXT: Running pass: GlobalOptPass

llvm/test/ThinLTO/X86/Inputs/cfi-unsat.ll

@@ -0,0 +1,68 @@
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-grtev4-linux-gnu"
+
+%struct.A = type { i32 (...)** }
+%struct.B = type { i32 (...)** }
+
+@_ZTV1B = linkonce_odr constant { [4 x i8*] } { [4 x i8*] [i8* null, i8* undef, i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1fEi to i8*), i8* bitcast (i32 (%struct.B*, i32)* @_ZN1B1nEi to i8*)] }, !type !0
+
+$test = comdat any
+$testb = comdat any
+
+define linkonce_odr i32 @test(%struct.A* %obj, i32 %a) comdat {
+entry:
+  %0 = bitcast %struct.A* %obj to i8**
+  %vtable5 = load i8*, i8** %0
+
+  %1 = tail call { i8*, i1 } @llvm.type.checked.load(i8* %vtable5, i32 8, metadata !"_ZTS1A")
+  %2 = extractvalue { i8*, i1 } %1, 1
+  br i1 %2, label %cont, label %trap
+
+trap:
+  tail call void @llvm.trap()
+  unreachable
+
+cont:
+  %3 = extractvalue { i8*, i1 } %1, 0
+  %4 = bitcast i8* %3 to i32 (%struct.A*, i32)*
+
+  %call = tail call i32 %4(%struct.A* nonnull %obj, i32 %a)
+
+  ret i32 %call
+}
+
+define linkonce_odr i32 @testb(%struct.A* %obj, i32 %a) comdat {
+entry:
+  %0 = bitcast %struct.A* %obj to i8**
+  %vtable5 = load i8*, i8** %0
+
+  %1 = tail call { i8*, i1 } @llvm.type.checked.load(i8* %vtable5, i32 0, metadata !"_ZTS1A")
+  %2 = extractvalue { i8*, i1 } %1, 1
+  br i1 %2, label %cont, label %trap
+
+trap:
+  tail call void @llvm.trap()
+  unreachable
+
+cont:
+  %3 = extractvalue { i8*, i1 } %1, 0
+  %4 = bitcast i8* %3 to i32 (%struct.A*, i32)*
+
+  %call = tail call i32 %4(%struct.A* nonnull %obj, i32 %a)
+
+  ret i32 %call
+}
+
+declare { i8*, i1 } @llvm.type.checked.load(i8*, i32, metadata)
+declare void @llvm.trap()
+
+define internal i32 @_ZN1B1fEi(%struct.B* %this, i32 %a) {
+entry:
+   ret i32 0
+}
+define internal i32 @_ZN1B1nEi(%struct.B* %this, i32 %a) {
+entry:
+   ret i32 0
+}
+
+!0 = !{i64 16, !"_ZTS1B"}

llvm/test/ThinLTO/X86/cfi-unsat.ll

@@ -0,0 +1,82 @@
+; REQUIRES: x86-registered-target
+
+; Test CFI devirtualization through the thin link and backend when
+; a type id is Unsat (not used on any global's type metadata).
+;
+; In this test case, the first module is split and will import a resolution
+; for its type test. The resolution would be exported by the second
+; module, which is set up so that it does not get split (treated as regular
+; LTO because it does not have any external globals from which to create
+; a unique module ID). We should not actually get any resolution for the
+; type id in this case, since no globals include it in their type metadata,
+; so the resolution is Unsat and the type.checked.load instructions are
+; converted to type tests that evaluate to false.
+
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t.o %s
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t1.o %p/Inputs/cfi-unsat.ll
+
+; RUN: llvm-lto2 run %t.o %t1.o -save-temps -use-new-pm -pass-remarks=. \
+; RUN:   -whole-program-visibility \
+; RUN:   -o %t3 \
+; RUN:   -r=%t.o,test2,px \
+; RUN:   -r=%t1.o,_ZTV1B,px \
+; RUN:   -r=%t1.o,test,px \
+; RUN:   -r=%t1.o,testb,px
+; RUN: llvm-dis %t3.index.bc -o - | FileCheck %s --check-prefix=INDEX
+; RUN: llvm-dis %t3.0.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR0
+; RUN: llvm-dis %t3.1.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR1
+
+; INDEX-NOT: "typeid:"
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-grtev4-linux-gnu"
+
+%struct.A = type { i32 (...)** }
+
+$test2 = comdat any
+
+define linkonce_odr i32 @test2(%struct.A* %obj, i32 %a) comdat {
+entry:
+  %0 = bitcast %struct.A* %obj to i8**
+  %vtable5 = load i8*, i8** %0
+
+  %1 = tail call { i8*, i1 } @llvm.type.checked.load(i8* %vtable5, i32 8, metadata !"_ZTS1A")
+  %2 = extractvalue { i8*, i1 } %1, 1
+  br i1 %2, label %cont, label %trap
+
+trap:
+  tail call void @llvm.trap()
+  unreachable
+
+cont:
+  %3 = extractvalue { i8*, i1 } %1, 0
+  %4 = bitcast i8* %3 to i32 (%struct.A*, i32)*
+
+  %call = tail call i32 %4(%struct.A* nonnull %obj, i32 %a)
+
+  ret i32 %call
+}
+
+; CHECK-IR0: define weak_odr i32 @test
+; CHECK-IR0-NEXT: entry:
+; CHECK-IR0-NEXT: %0 = bitcast
+; CHECK-IR0-NEXT: %vtable5 =
+; CHECK-IR0-NEXT: tail call void @llvm.trap()
+; CHECK-IR0-NEXT: unreachable
+; CHECK-IR0-NEXT: }
+; CHECK-IR0: define weak_odr i32 @testb
+; CHECK-IR0-NEXT: entry:
+; CHECK-IR0-NEXT: %0 = bitcast
+; CHECK-IR0-NEXT: %vtable5 =
+; CHECK-IR0-NEXT: tail call void @llvm.trap()
+; CHECK-IR0-NEXT: unreachable
+; CHECK-IR0-NEXT: }
+
+; CHECK-IR1: define weak_odr i32 @test2
+; CHECK-IR1-NEXT:   entry:
+; CHECK-IR1-NEXT:     tail call void @llvm.trap()
+; CHECK-IR1-NEXT:     unreachable
+; CHECK-IR1-NEXT:   }
+
+declare { i8*, i1 } @llvm.type.checked.load(i8*, i32, metadata)
+declare void @llvm.trap()

llvm/test/ThinLTO/X86/nodevirt-nonpromoted-typeid.ll

@@ -33,6 +33,8 @@
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-grtev4-linux-gnu"
 
+@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @g, i8* null }]
+
 %struct.D = type { i32 (...)** }
 
 @_ZTV1D = internal constant { [3 x i8*] } { [3 x i8*] [i8* null, i8* undef, i8* bitcast (i32 (%struct.D*, i32)* @_ZN1D1mEi to i8*)] }, !type !3
@@ -57,6 +59,23 @@ entry:
 ; CHECK-IR-LABEL: ret i32
 ; CHECK-IR-LABEL: }
 
+; Function Attrs: inlinehint nounwind uwtable
+define internal void @_ZN1DC2Ev(%struct.D* %this) unnamed_addr align 2 {
+entry:
+  %this.addr = alloca %struct.D*, align 8
+  store %struct.D* %this, %struct.D** %this.addr, align 8
+  %this1 = load %struct.D*, %struct.D** %this.addr
+  %0 = bitcast %struct.D* %this1 to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [3 x i8*] }, { [3 x i8*] }* @_ZTV1D, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
+  ret void
+}
+
+define internal void @g() section ".text.startup" {
+  %d = alloca %struct.D, align 8
+  call void @_ZN1DC2Ev(%struct.D* %d)
+  ret void
+}
+
 declare i1 @llvm.type.test(i8*, metadata)
 declare void @llvm.assume(i1)
 

llvm/test/ThinLTO/X86/type_test_noindircall.ll

@@ -0,0 +1,59 @@
+; Test to ensure that we correctly handle a type test not used for a virtual call.
+; If it isn't removed correctly by WPD then we could incorrectly get an Unsat
+; (resulting in an unreachable in the IR).
+
+; REQUIRES: x86-registered-target
+
+; RUN: opt -thinlto-bc -o %t.o %s
+
+; FIXME: Fix machine verifier issues and remove -verify-machineinstrs=0. PR39436.
+; RUN: llvm-lto2 run %t.o -save-temps -pass-remarks=. \
+; RUN:   -whole-program-visibility \
+; RUN:   -verify-machineinstrs=0 \
+; RUN:	 -r=%t.o,_ZTVN12_GLOBAL__N_18RealFileE,px \
+; RUN:   -o %t2
+; RUN: llvm-dis %t2.1.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR
+
+; Try again without LTO unit splitting.
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit=false -o %t3.o %s
+; RUN: llvm-lto2 run %t.o -save-temps -pass-remarks=. \
+; RUN:   -whole-program-visibility \
+; RUN:   -verify-machineinstrs=0 \
+; RUN:	 -r=%t.o,_ZTVN12_GLOBAL__N_18RealFileE,px \
+; RUN:   -o %t4
+; RUN: llvm-dis %t4.1.4.opt.bc -o - | FileCheck %s --check-prefix=CHECK-IR
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-grtev4-linux-gnu"
+
+%"class.llvm::vfs::File" = type { i32 (...)** }
+%"class.llvm::vfs::Status" = type <{ %"class.std::__cxx11::basic_string", %"class.llvm::sys::fs::UniqueID", %"struct.std::chrono::time_point", i32, i32, i64, i32, i32, i8, [7 x i8] }>
+%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider", i64, %union.anon }
+%"struct.std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider" = type { i8* }
+%union.anon = type { i64, [8 x i8] }
+%"class.llvm::sys::fs::UniqueID" = type { i64, i64 }
+%"struct.std::chrono::time_point" = type { %"struct.std::chrono::duration" }
+%"struct.std::chrono::duration" = type { i64 }
+%"class.(anonymous namespace)::RealFile" = type { %"class.llvm::vfs::File", i32, [4 x i8], %"class.llvm::vfs::Status", %"class.std::__cxx11::basic_string" }
+
+@_ZTVN12_GLOBAL__N_18RealFileE = unnamed_addr constant { [3 x i8*] } { [3 x i8*] [i8* null, i8* null, i8* bitcast (void (%"class.(anonymous namespace)::RealFile"*)* @_ZN12_GLOBAL__N_18RealFileD2Ev to i8*)] }, align 8, !type !74
+
+define internal void @_ZN12_GLOBAL__N_18RealFileD2Ev(%"class.(anonymous namespace)::RealFile"* %this) unnamed_addr #0 align 2 {
+entry:
+; CHECK-IR: %0 = getelementptr
+  %0 = getelementptr %"class.(anonymous namespace)::RealFile", %"class.(anonymous namespace)::RealFile"* %this, i64 0, i32 0, i32 0
+; CHECK-IR-NEXT: store
+  store i32 (...)** bitcast (i8** getelementptr inbounds ({ [3 x i8*] }, { [3 x i8*] }* @_ZTVN12_GLOBAL__N_18RealFileE, i64 0, inrange i32 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
+  %1 = tail call i1 @llvm.type.test(i8* bitcast (i8** getelementptr inbounds ({ [3 x i8*] }, { [3 x i8*] }* @_ZTVN12_GLOBAL__N_18RealFileE, i64 0, inrange i32 0, i64 2) to i8*), metadata !"4$09c6cc733fc6accb91e5d7b87cb48f2d")
+  tail call void @llvm.assume(i1 %1)
+; CHECK-IR-NEXT: ret void
+  ret void
+}
+
+declare i1 @llvm.type.test(i8*, metadata)
+declare void @llvm.assume(i1)
+
+; Make sure we don't inline or otherwise optimize out the direct calls.
+attributes #0 = { noinline optnone }
+
+!74 = !{i64 16, !"4$09c6cc733fc6accb91e5d7b87cb48f2d"}

llvm/test/Transforms/WholeProgramDevirt/branch-funnel.ll

@@ -10,7 +10,7 @@
 ; SUMMARY:      TypeIdMap:       
 ; SUMMARY-NEXT:   typeid3:
 ; SUMMARY-NEXT:     TTRes:           
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -23,7 +23,7 @@
 ; SUMMARY-NEXT:         ResByArg:        
 ; SUMMARY-NEXT:   typeid1:
 ; SUMMARY-NEXT:     TTRes:           
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -36,7 +36,7 @@
 ; SUMMARY-NEXT:         ResByArg:        
 ; SUMMARY-NEXT:   typeid2:
 ; SUMMARY-NEXT:     TTRes:           
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0

llvm/test/Transforms/WholeProgramDevirt/devirt-single-impl2.ll

@@ -14,7 +14,7 @@
 ; RUN:     -wholeprogramdevirt-summary-action=export -o /dev/null 2>&1 | FileCheck %s --check-prefix=MISSING-MODULE
 
 ; Check single impl devirtulation in summary
-; CHECK: typeid: (name: "_ZTS1A", summary: (typeTestRes: (kind: unsat, sizeM1BitWidth: 0), wpdResolutions: ((offset: 0, wpdRes: (kind: singleImpl, singleImplName: "_ZNK1A1fEv"))))) ; guid
+; CHECK: typeid: (name: "_ZTS1A", summary: (typeTestRes: (kind: unknown, sizeM1BitWidth: 0), wpdResolutions: ((offset: 0, wpdRes: (kind: singleImpl, singleImplName: "_ZNK1A1fEv"))))) ; guid
 
 ; MISSING-MODULE: combined summary should contain Regular LTO module
 

llvm/test/Transforms/WholeProgramDevirt/export-single-impl.ll

@@ -4,7 +4,7 @@
 ; SUMMARY:      TypeIdMap:
 ; SUMMARY-NEXT:   typeid3:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -17,7 +17,7 @@
 ; SUMMARY-NEXT:         ResByArg:
 ; SUMMARY-NEXT:   typeid1:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -30,7 +30,7 @@
 ; SUMMARY-NEXT:         ResByArg:
 ; SUMMARY-NEXT:   typeid2:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -43,7 +43,7 @@
 ; SUMMARY-NEXT:         ResByArg:
 ; SUMMARY-NEXT:   typeid4:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0

llvm/test/Transforms/WholeProgramDevirt/export-uniform-ret-val.ll

@@ -6,7 +6,7 @@
 ; SUMMARY:      TypeIdMap:
 ; SUMMARY-NEXT:   typeid4:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0

llvm/test/Transforms/WholeProgramDevirt/export-unique-ret-val.ll

@@ -6,7 +6,7 @@
 ; SUMMARY:      TypeIdMap:
 ; SUMMARY-NEXT:   typeid3:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -24,7 +24,7 @@
 ; SUMMARY-NEXT:             Bit:             0
 ; SUMMARY-NEXT:   typeid4:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0

llvm/test/Transforms/WholeProgramDevirt/export-vcp.ll

@@ -9,7 +9,7 @@ target datalayout = "e-p:64:64"
 ; SUMMARY:      TypeIdMap:
 ; SUMMARY-NEXT:   typeid3:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0
@@ -29,7 +29,7 @@ target datalayout = "e-p:64:64"
 ; SUMMARY-ARM-NEXT:         Bit:             1
 ; SUMMARY-NEXT:   typeid4:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0

llvm/test/Transforms/WholeProgramDevirt/import-indir.ll

@@ -32,7 +32,7 @@
 ; SUMMARY-NEXT: TypeIdMap:
 ; SUMMARY-NEXT:   typeid1:
 ; SUMMARY-NEXT:     TTRes:
-; SUMMARY-NEXT:       Kind:            Unsat
+; SUMMARY-NEXT:       Kind:            Unknown
 ; SUMMARY-NEXT:       SizeM1BitWidth:  0
 ; SUMMARY-NEXT:       AlignLog2:       0
 ; SUMMARY-NEXT:       SizeM1:          0

llvm/test/Transforms/WholeProgramDevirt/uniform-retval.ll

@@ -25,7 +25,7 @@ define i32 @call(i8* %obj) {
   %fptr = load i8*, i8** %fptrptr
   %fptr_casted = bitcast i8* %fptr to i32 (i8*)*
   %result = call i32 %fptr_casted(i8* %obj)
-  ; CHECK-NOT: call
+  ; CHECK-NOT: call i32 %
   ; CHECK: ret i32 123
   ret i32 %result
 }