vendor/llvm-project/llvmorg-10-init-17466-ge26a78e7085

1 files changed, 77 insertions, 38 deletions

diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index 3f5cc078d75fc..be0446a946ec5 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -31,6 +31,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/ModuleSummaryIndex.h"
 #include "llvm/IRReader/IRReader.h"
+#include "llvm/InitializePasses.h"
 #include "llvm/Linker/IRMover.h"
 #include "llvm/Object/ModuleSymbolTable.h"
 #include "llvm/Object/SymbolicFile.h"
@@ -231,7 +232,8 @@ selectCallee(const ModuleSummaryIndex &Index,
           return false;
         }
 
-        if (Summary->instCount() > Threshold) {
+        if ((Summary->instCount() > Threshold) &&
+            !Summary->fflags().AlwaysInline) {
           Reason = FunctionImporter::ImportFailureReason::TooLarge;
           return false;
         }
@@ -280,7 +282,8 @@ updateValueInfoForIndirectCalls(const ModuleSummaryIndex &Index, ValueInfo VI) {
 }
 
 static void computeImportForReferencedGlobals(
-    const FunctionSummary &Summary, const GVSummaryMapTy &DefinedGVSummaries,
+    const FunctionSummary &Summary, const ModuleSummaryIndex &Index,
+    const GVSummaryMapTy &DefinedGVSummaries,
     FunctionImporter::ImportMapTy &ImportList,
     StringMap<FunctionImporter::ExportSetTy> *ExportLists) {
   for (auto &VI : Summary.refs()) {
@@ -303,16 +306,28 @@ static void computeImportForReferencedGlobals(
              RefSummary->modulePath() != Summary.modulePath();
     };
 
+    auto MarkExported = [&](const ValueInfo &VI, const GlobalValueSummary *S) {
+      if (ExportLists)
+        (*ExportLists)[S->modulePath()].insert(VI);
+    };
+
     for (auto &RefSummary : VI.getSummaryList())
       if (isa<GlobalVarSummary>(RefSummary.get()) &&
-          canImportGlobalVar(RefSummary.get()) &&
+          Index.canImportGlobalVar(RefSummary.get(), /* AnalyzeRefs */ true) &&
           !LocalNotInModule(RefSummary.get())) {
         auto ILI = ImportList[RefSummary->modulePath()].insert(VI.getGUID());
         // Only update stat if we haven't already imported this variable.
         if (ILI.second)
           NumImportedGlobalVarsThinLink++;
-        if (ExportLists)
-          (*ExportLists)[RefSummary->modulePath()].insert(VI.getGUID());
+        MarkExported(VI, RefSummary.get());
+        // Promote referenced functions and variables. We don't promote
+        // objects referenced by writeonly variable initializer, because
+        // we convert such variables initializers to "zeroinitializer".
+        // See processGlobalForThinLTO.
+        if (!Index.isWriteOnly(cast<GlobalVarSummary>(RefSummary.get())))
+          for (const auto &VI : RefSummary->refs())
+            for (const auto &RefFn : VI.getSummaryList())
+              MarkExported(VI, RefFn.get());
         break;
       }
   }
@@ -351,8 +366,8 @@ static void computeImportForFunction(
     FunctionImporter::ImportMapTy &ImportList,
     StringMap<FunctionImporter::ExportSetTy> *ExportLists,
     FunctionImporter::ImportThresholdsTy &ImportThresholds) {
-  computeImportForReferencedGlobals(Summary, DefinedGVSummaries, ImportList,
-                                    ExportLists);
+  computeImportForReferencedGlobals(Summary, Index, DefinedGVSummaries,
+                                    ImportList, ExportLists);
   static int ImportCount = 0;
   for (auto &Edge : Summary.calls()) {
     ValueInfo VI = Edge.first;
@@ -462,7 +477,8 @@ static void computeImportForFunction(
       CalleeSummary = CalleeSummary->getBaseObject();
       ResolvedCalleeSummary = cast<FunctionSummary>(CalleeSummary);
 
-      assert(ResolvedCalleeSummary->instCount() <= NewThreshold &&
+      assert((ResolvedCalleeSummary->fflags().AlwaysInline ||
+	     (ResolvedCalleeSummary->instCount() <= NewThreshold)) &&
              "selectCallee() didn't honor the threshold");
 
       auto ExportModulePath = ResolvedCalleeSummary->modulePath();
@@ -481,7 +497,7 @@ static void computeImportForFunction(
       // Make exports in the source module.
       if (ExportLists) {
         auto &ExportList = (*ExportLists)[ExportModulePath];
-        ExportList.insert(VI.getGUID());
+        ExportList.insert(VI);
         if (!PreviouslyImported) {
           // This is the first time this function was exported from its source
           // module, so mark all functions and globals it references as exported
@@ -489,14 +505,11 @@ static void computeImportForFunction(
           // For efficiency, we unconditionally add all the referenced GUIDs
           // to the ExportList for this module, and will prune out any not
           // defined in the module later in a single pass.
-          for (auto &Edge : ResolvedCalleeSummary->calls()) {
-            auto CalleeGUID = Edge.first.getGUID();
-            ExportList.insert(CalleeGUID);
-          }
-          for (auto &Ref : ResolvedCalleeSummary->refs()) {
-            auto GUID = Ref.getGUID();
-            ExportList.insert(GUID);
-          }
+          for (auto &Edge : ResolvedCalleeSummary->calls())
+            ExportList.insert(Edge.first);
+
+          for (auto &Ref : ResolvedCalleeSummary->refs())
+            ExportList.insert(Ref);
         }
       }
     }
@@ -591,29 +604,64 @@ static void ComputeImportForModule(
 }
 
 #ifndef NDEBUG
+static bool isGlobalVarSummary(const ModuleSummaryIndex &Index, ValueInfo VI) {
+  auto SL = VI.getSummaryList();
+  return SL.empty()
+             ? false
+             : SL[0]->getSummaryKind() == GlobalValueSummary::GlobalVarKind;
+}
+
 static bool isGlobalVarSummary(const ModuleSummaryIndex &Index,
                                GlobalValue::GUID G) {
-  if (const auto &VI = Index.getValueInfo(G)) {
-    auto SL = VI.getSummaryList();
-    if (!SL.empty())
-      return SL[0]->getSummaryKind() == GlobalValueSummary::GlobalVarKind;
-  }
+  if (const auto &VI = Index.getValueInfo(G))
+    return isGlobalVarSummary(Index, VI);
   return false;
 }
 
-static GlobalValue::GUID getGUID(GlobalValue::GUID G) { return G; }
-
 template <class T>
 static unsigned numGlobalVarSummaries(const ModuleSummaryIndex &Index,
                                       T &Cont) {
   unsigned NumGVS = 0;
   for (auto &V : Cont)
-    if (isGlobalVarSummary(Index, getGUID(V)))
+    if (isGlobalVarSummary(Index, V))
       ++NumGVS;
   return NumGVS;
 }
 #endif
 
+#ifndef NDEBUG
+static bool
+checkVariableImport(const ModuleSummaryIndex &Index,
+                    StringMap<FunctionImporter::ImportMapTy> &ImportLists,
+                    StringMap<FunctionImporter::ExportSetTy> &ExportLists) {
+
+  DenseSet<GlobalValue::GUID> FlattenedImports;
+
+  for (auto &ImportPerModule : ImportLists)
+    for (auto &ExportPerModule : ImportPerModule.second)
+      FlattenedImports.insert(ExportPerModule.second.begin(),
+                              ExportPerModule.second.end());
+
+  // Checks that all GUIDs of read/writeonly vars we see in export lists
+  // are also in the import lists. Otherwise we my face linker undefs,
+  // because readonly and writeonly vars are internalized in their
+  // source modules.
+  auto IsReadOrWriteOnlyVar = [&](StringRef ModulePath, const ValueInfo &VI) {
+    auto *GVS = dyn_cast_or_null<GlobalVarSummary>(
+        Index.findSummaryInModule(VI, ModulePath));
+    return GVS && (Index.isReadOnly(GVS) || Index.isWriteOnly(GVS));
+  };
+
+  for (auto &ExportPerModule : ExportLists)
+    for (auto &VI : ExportPerModule.second)
+      if (!FlattenedImports.count(VI.getGUID()) &&
+          IsReadOrWriteOnlyVar(ExportPerModule.first(), VI))
+        return false;
+
+  return true;
+}
+#endif
+
 /// Compute all the import and export for every module using the Index.
 void llvm::ComputeCrossModuleImport(
     const ModuleSummaryIndex &Index,
@@ -639,13 +687,14 @@ void llvm::ComputeCrossModuleImport(
     const auto &DefinedGVSummaries =
         ModuleToDefinedGVSummaries.lookup(ELI.first());
     for (auto EI = ELI.second.begin(); EI != ELI.second.end();) {
-      if (!DefinedGVSummaries.count(*EI))
-        EI = ELI.second.erase(EI);
+      if (!DefinedGVSummaries.count(EI->getGUID()))
+        ELI.second.erase(EI++);
       else
         ++EI;
     }
   }
 
+  assert(checkVariableImport(Index, ImportLists, ExportLists));
 #ifndef NDEBUG
   LLVM_DEBUG(dbgs() << "Import/Export lists for " << ImportLists.size()
                     << " modules:\n");
@@ -852,18 +901,8 @@ void llvm::computeDeadSymbolsWithConstProp(
     function_ref<PrevailingType(GlobalValue::GUID)> isPrevailing,
     bool ImportEnabled) {
   computeDeadSymbols(Index, GUIDPreservedSymbols, isPrevailing);
-  if (ImportEnabled) {
+  if (ImportEnabled)
     Index.propagateAttributes(GUIDPreservedSymbols);
-  } else {
-    // If import is disabled we should drop read/write-only attribute
-    // from all summaries to prevent internalization.
-    for (auto &P : Index)
-      for (auto &S : P.second.SummaryList)
-        if (auto *GVS = dyn_cast<GlobalVarSummary>(S.get())) {
-          GVS->setReadOnly(false);
-          GVS->setWriteOnly(false);
-        }
-  }
 }
 
 /// Compute the set of summaries needed for a ThinLTO backend compilation of