vendor/llvm/llvm-trunk-r304659

1 files changed, 27 insertions, 16 deletions

diff --git a/lib/LTO/LTO.cpp b/lib/LTO/LTO.cpp
index 9efc095f9fcf..92145aaf667a 100644
--- a/lib/LTO/LTO.cpp
+++ b/lib/LTO/LTO.cpp
@@ -122,6 +122,7 @@ static void computeCacheKey(
   AddUnsigned(Conf.CGOptLevel);
   AddUnsigned(Conf.CGFileType);
   AddUnsigned(Conf.OptLevel);
+  AddUnsigned(Conf.UseNewPM);
   AddString(Conf.OptPipeline);
   AddString(Conf.AAPipeline);
   AddString(Conf.OverrideTriple);
@@ -621,6 +622,19 @@ unsigned LTO::getMaxTasks() const {
 }
 
 Error LTO::run(AddStreamFn AddStream, NativeObjectCache Cache) {
+  // Compute "dead" symbols, we don't want to import/export these!
+  DenseSet<GlobalValue::GUID> GUIDPreservedSymbols;
+  for (auto &Res : GlobalResolutions) {
+    if (Res.second.VisibleOutsideThinLTO &&
+        // IRName will be defined if we have seen the prevailing copy of
+        // this value. If not, no need to preserve any ThinLTO copies.
+        !Res.second.IRName.empty())
+      GUIDPreservedSymbols.insert(GlobalValue::getGUID(
+          GlobalValue::dropLLVMManglingEscape(Res.second.IRName)));
+  }
+
+  computeDeadSymbols(ThinLTO.CombinedIndex, GUIDPreservedSymbols);
+
   // Save the status of having a regularLTO combined module, as
   // this is needed for generating the ThinLTO Task ID, and
   // the CombinedModule will be moved at the end of runRegularLTO.
@@ -930,6 +944,17 @@ ThinBackend lto::createWriteIndexesThinBackend(std::string OldPrefix,
   };
 }
 
+static bool IsLiveByGUID(const ModuleSummaryIndex &Index,
+                         GlobalValue::GUID GUID) {
+  auto VI = Index.getValueInfo(GUID);
+  if (!VI)
+    return false;
+  for (auto &I : VI.getSummaryList())
+    if (Index.isGlobalValueLive(I.get()))
+      return true;
+  return false;
+}
+
 Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache,
                       bool HasRegularLTO) {
   if (ThinLTO.ModuleMap.empty())
@@ -962,22 +987,8 @@ Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache,
   StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR;
 
   if (Conf.OptLevel > 0) {
-    // Compute "dead" symbols, we don't want to import/export these!
-    DenseSet<GlobalValue::GUID> GUIDPreservedSymbols;
-    for (auto &Res : GlobalResolutions) {
-      if (Res.second.VisibleOutsideThinLTO &&
-          // IRName will be defined if we have seen the prevailing copy of
-          // this value. If not, no need to preserve any ThinLTO copies.
-          !Res.second.IRName.empty())
-        GUIDPreservedSymbols.insert(GlobalValue::getGUID(
-            GlobalValue::dropLLVMManglingEscape(Res.second.IRName)));
-    }
-
-    auto DeadSymbols =
-        computeDeadSymbols(ThinLTO.CombinedIndex, GUIDPreservedSymbols);
-
     ComputeCrossModuleImport(ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries,
-                             ImportLists, ExportLists, &DeadSymbols);
+                             ImportLists, ExportLists);
 
     std::set<GlobalValue::GUID> ExportedGUIDs;
     for (auto &Res : GlobalResolutions) {
@@ -992,7 +1003,7 @@ Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache,
       auto GUID = GlobalValue::getGUID(
           GlobalValue::dropLLVMManglingEscape(Res.second.IRName));
       // Mark exported unless index-based analysis determined it to be dead.
-      if (!DeadSymbols.count(GUID))
+      if (IsLiveByGUID(ThinLTO.CombinedIndex, GUID))
         ExportedGUIDs.insert(GUID);
     }