[GlobalDCE, Misc] Don't remove functions referenced by ifuncs

We forgot to consider the target of ifuncs when considering if a
function was alive or dead.

N.B. Also update a few auxiliary tools like bugpoint and
verify-uselistorder.

This fixes PR27593.

llvm-svn: 268468

1 files changed, 7 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/Utils/SplitModule.cpp b/llvm/lib/Transforms/Utils/SplitModule.cpp
index 6b0ce9c..3db04b8 100644
--- a/llvm/lib/Transforms/Utils/SplitModule.cpp
+++ b/llvm/lib/Transforms/Utils/SplitModule.cpp
@@ -47,7 +47,7 @@ static void addNonConstUser(ClusterMapType &GVtoClusterMap,
   if (const Instruction *I = dyn_cast<Instruction>(U)) {
     const GlobalValue *F = I->getParent()->getParent();
     GVtoClusterMap.unionSets(GV, F);
-  } else if (isa<GlobalAlias>(U) || isa<Function>(U) ||
+  } else if (isa<GlobalIndirectSymbol>(U) || isa<Function>(U) ||
              isa<GlobalVariable>(U)) {
     GVtoClusterMap.unionSets(GV, cast<GlobalValue>(U));
   } else {
@@ -107,8 +107,8 @@ static void findPartitions(Module *M, ClusterIDMapType &ClusterIDMap,
 
     // For aliases we should not separate them from their aliasees regardless
     // of linkage.
-    if (GlobalAlias *GA = dyn_cast<GlobalAlias>(&GV)) {
-      if (const GlobalObject *Base = GA->getBaseObject())
+    if (auto *GIS = dyn_cast<GlobalIndirectSymbol>(&GV)) {
+      if (const GlobalObject *Base = GIS->getBaseObject())
         GVtoClusterMap.unionSets(&GV, Base);
     }
 
@@ -205,8 +205,8 @@ static void externalize(GlobalValue *GV) {
 
 // Returns whether GV should be in partition (0-based) I of N.
 static bool isInPartition(const GlobalValue *GV, unsigned I, unsigned N) {
-  if (auto GA = dyn_cast<GlobalAlias>(GV))
-    if (const GlobalObject *Base = GA->getBaseObject())
+  if (auto *GIS = dyn_cast<GlobalIndirectSymbol>(GV))
+    if (const GlobalObject *Base = GIS->getBaseObject())
       GV = Base;
 
   StringRef Name;
@@ -236,6 +236,8 @@ void llvm::SplitModule(
       externalize(&GV);
     for (GlobalAlias &GA : M->aliases())
       externalize(&GA);
+    for (GlobalIFunc &GIF : M->ifuncs())
+      externalize(&GIF);
   }
 
   // This performs splitting without a need for externalization, which might not