Clarify that llvm.used can contain aliases.

Also add a check for llvm.used in the verifier and simplify clients now that
they can assume they have a ConstantArray.

llvm-svn: 180019

3 files changed, 7 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/IPO/ConstantMerge.cpp b/llvm/lib/Transforms/IPO/ConstantMerge.cpp
index 8336d3ad347..b63495b9685 100644
--- a/llvm/lib/Transforms/IPO/ConstantMerge.cpp
+++ b/llvm/lib/Transforms/IPO/ConstantMerge.cpp
@@ -66,9 +66,8 @@ ModulePass *llvm::createConstantMergePass() { return new ConstantMerge(); }
 static void FindUsedValues(GlobalVariable *LLVMUsed,
                            SmallPtrSet<const GlobalValue*, 8> &UsedValues) {
   if (LLVMUsed == 0) return;
-  ConstantArray *Inits = dyn_cast<ConstantArray>(LLVMUsed->getInitializer());
-  if (Inits == 0) return;
-  
+  ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
+
   for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
     if (GlobalValue *GV = 
         dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
diff --git a/llvm/lib/Transforms/IPO/StripSymbols.cpp b/llvm/lib/Transforms/IPO/StripSymbols.cpp
index 5f8681ff454..3396f7929e6 100644
--- a/llvm/lib/Transforms/IPO/StripSymbols.cpp
+++ b/llvm/lib/Transforms/IPO/StripSymbols.cpp
@@ -195,10 +195,9 @@ static void findUsedValues(GlobalVariable *LLVMUsed,
                            SmallPtrSet<const GlobalValue*, 8> &UsedValues) {
   if (LLVMUsed == 0) return;
   UsedValues.insert(LLVMUsed);
-  
-  ConstantArray *Inits = dyn_cast<ConstantArray>(LLVMUsed->getInitializer());
-  if (Inits == 0) return;
-  
+
+  ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
+
   for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
     if (GlobalValue *GV = 
           dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
diff --git a/llvm/lib/Transforms/Scalar/GlobalMerge.cpp b/llvm/lib/Transforms/Scalar/GlobalMerge.cpp
index 5d02c68a7a4..4796eb2953a 100644
--- a/llvm/lib/Transforms/Scalar/GlobalMerge.cpp
+++ b/llvm/lib/Transforms/Scalar/GlobalMerge.cpp
@@ -200,9 +200,8 @@ void GlobalMerge::collectUsedGlobalVariables(Module &M) {
   if (!GV || !GV->hasInitializer()) return;
 
   // Should be an array of 'i8*'.
-  const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
-  if (InitList == 0) return;
- 
+  const ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
+
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
     if (const GlobalVariable *G =
         dyn_cast<GlobalVariable>(InitList->getOperand(i)->stripPointerCasts()))