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

This reverts commit 748bb5a0f1964d20dfb3891b0948ab6c66236c70.

Due to Chromium CFI+ThinLTO test crashes reported on patch.

1 files changed, 18 insertions, 36 deletions

diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
index 03e1fdd3..bbc1433a 100644
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -510,9 +510,7 @@ struct DevirtModule {
 
   bool areRemarksEnabled();
 
-  void
-  scanTypeTestUsers(Function *TypeTestFunc,
-                    DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap);
+  void scanTypeTestUsers(Function *TypeTestFunc);
   void scanTypeCheckedLoadUsers(Function *TypeCheckedLoadFunc);
 
   void buildTypeIdentifierMap(
@@ -1668,9 +1666,7 @@ bool DevirtModule::areRemarksEnabled() {
   return false;
 }
 
-void DevirtModule::scanTypeTestUsers(
-    Function *TypeTestFunc,
-    DenseMap<Metadata *, std::set<TypeMemberInfo>> &TypeIdMap) {
+void DevirtModule::scanTypeTestUsers(Function *TypeTestFunc) {
   // 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,
@@ -1690,10 +1686,10 @@ void DevirtModule::scanTypeTestUsers(
     auto &DT = LookupDomTree(*CI->getFunction());
     findDevirtualizableCallsForTypeTest(DevirtCalls, Assumes, CI, DT);
 
-    Metadata *TypeId =
-        cast<MetadataAsValue>(CI->getArgOperand(1))->getMetadata();
     // If we found any, add them to CallSlots.
     if (!Assumes.empty()) {
+      Metadata *TypeId =
+          cast<MetadataAsValue>(CI->getArgOperand(1))->getMetadata();
       Value *Ptr = CI->getArgOperand(0)->stripPointerCasts();
       for (DevirtCallSite Call : DevirtCalls) {
         // Only add this CallSite if we haven't seen it before. The vtable
@@ -1706,13 +1702,6 @@ void DevirtModule::scanTypeTestUsers(
       }
     }
 
-    // If we have any uses on type metadata, keep the type test assumes for
-    // later analysis. Otherwise remove as they aren't useful, and
-    // LowerTypeTests will think they are Unsat and lower to False, which
-    // breaks any uses on assumes.
-    if (TypeIdMap.count(TypeId))
-      continue;
-
     // We no longer need the assumes or the type test.
     for (auto Assume : Assumes)
       Assume->eraseFromParent();
@@ -1911,13 +1900,8 @@ 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, TypeIdMap);
+    scanTypeTestUsers(TypeTestFunc);
 
   if (TypeCheckedLoadFunc)
     scanTypeCheckedLoadUsers(TypeCheckedLoadFunc);
@@ -1939,6 +1923,10 @@ 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;
 
@@ -1995,17 +1983,14 @@ bool DevirtModule::run() {
     // function implementation at offset S.first.ByteOffset, and add to
     // TargetsForSlot.
     std::vector<VirtualCallTarget> TargetsForSlot;
-    WholeProgramDevirtResolution *Res = nullptr;
-    if (ExportSummary && isa<MDString>(S.first.TypeID))
-      // Create the type id summary resolution regardlness of whether we can
-      // devirtualize, so that lower type tests knows the type id is used on
-      // a global and not Unsat.
-      Res = &ExportSummary
-                 ->getOrInsertTypeIdSummary(
-                     cast<MDString>(S.first.TypeID)->getString())
-                 .WPDRes[S.first.ByteOffset];
     if (tryFindVirtualCallTargets(TargetsForSlot, TypeIdMap[S.first.TypeID],
                                   S.first.ByteOffset)) {
+      WholeProgramDevirtResolution *Res = nullptr;
+      if (ExportSummary && isa<MDString>(S.first.TypeID))
+        Res = &ExportSummary
+                   ->getOrInsertTypeIdSummary(
+                       cast<MDString>(S.first.TypeID)->getString())
+                   .WPDRes[S.first.ByteOffset];
 
       if (!trySingleImplDevirt(ExportSummary, TargetsForSlot, S.second, Res)) {
         DidVirtualConstProp |=
@@ -2119,14 +2104,11 @@ void DevirtIndex::run() {
     std::vector<ValueInfo> TargetsForSlot;
     auto TidSummary = ExportSummary.getTypeIdCompatibleVtableSummary(S.first.TypeID);
     assert(TidSummary);
-    // Create the type id summary resolution regardlness of whether we can
-    // 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)) {
+      WholeProgramDevirtResolution *Res =
+          &ExportSummary.getOrInsertTypeIdSummary(S.first.TypeID)
+               .WPDRes[S.first.ByteOffset];
 
       if (!trySingleImplDevirt(TargetsForSlot, S.first, S.second, Res,
                                DevirtTargets))