IR: Introduce Module::global_objects().

This is a convenience iterator that allows clients to enumerate the
GlobalObjects within a Module.

Also start using it in a few places where it is obviously the right thing
to use.

Differential Revision: http://reviews.llvm.org/D21580

llvm-svn: 273470

1 files changed, 6 insertions, 13 deletions

diff --git a/llvm/lib/Transforms/IPO/GlobalDCE.cpp b/llvm/lib/Transforms/IPO/GlobalDCE.cpp
index f30e69ccbcd..4c74698a1b6 100644
--- a/llvm/lib/Transforms/IPO/GlobalDCE.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalDCE.cpp
@@ -96,21 +96,14 @@ PreservedAnalyses GlobalDCEPass::run(Module &M, ModuleAnalysisManager &) {
       ComdatMembers.insert(std::make_pair(C, &GA));
 
   // Loop over the module, adding globals which are obviously necessary.
-  for (Function &F : M) {
-    Changed |= RemoveUnusedGlobalValue(F);
-    // Functions with external linkage are needed if they have a body
-    if (!F.isDeclaration() && !F.hasAvailableExternallyLinkage())
-      if (!F.isDiscardableIfUnused())
-        GlobalIsNeeded(&F);
-  }
-
-  for (GlobalVariable &GV : M.globals()) {
-    Changed |= RemoveUnusedGlobalValue(GV);
+  for (GlobalObject &GO : M.global_objects()) {
+    Changed |= RemoveUnusedGlobalValue(GO);
+    // Functions with external linkage are needed if they have a body.
     // Externally visible & appending globals are needed, if they have an
     // initializer.
-    if (!GV.isDeclaration() && !GV.hasAvailableExternallyLinkage())
-      if (!GV.isDiscardableIfUnused())
-        GlobalIsNeeded(&GV);
+    if (!GO.isDeclaration() && !GO.hasAvailableExternallyLinkage())
+      if (!GO.isDiscardableIfUnused())
+        GlobalIsNeeded(&GO);
   }
 
   for (GlobalAlias &GA : M.aliases()) {